Ventricular cardiac rhythm disorders. Sudden cardiac death: clinical guidelines

List of Abbreviations

AAT – antiarrhythmic therapy

AAD – antiarrhythmic drug (C01B Antiarrhythmics, class I and III)

(AAD class IA – ATC C01BA Antiarrhythmic drugs, class IA

AAD class IB – ATC C01BB Antiarrhythmic drugs, class IB

AAD class IC – ATC C01BC Antiarrhythmic drugs, class IC

AAD class III – ATC C01BD Antiarrhythmic drugs, class III)

AV – atrioventricular

AH – arterial hypertension

BP – blood pressure

ARVC – arrhythmogenic right ventricular cardiomyopathy

ARB – angiotensin II receptor blocker (ATC C09CA Angiotensin II receptor blockers)

ARNI – angiotensin II receptor blockers in combination with other agents (ATC C09DX04 valsartan + sacubitril**)

ATC – Anatomical Therapeutic Chemical classification system

SCD – sudden cardiac death

CHD – congenital heart disease

SCD – sudden cardiac death

IEFS – intracardiac electrophysiological study

LVOT – left ventricular outflow tract

RVOT – right ventricular outflow tract

ГКМП – hypertrophic cardiomyopathy

DCM – dilated cardiomyopathy

ESC – European Society of Cardiology

AP – accessory pathway

ИМ – myocardial infarction

STEMI – ST-segment elevation myocardial infarction

VA – ventricular arrhythmia

VRA – ventricular rhythm abnormalities

VTA – ventricular tachyarrhythmia

VT – ventricular tachycardia

VES – ventricular extrasystole

ACE inhibitor – angiotensin-converting enzyme inhibitor (ATC C09A ACE inhibitors)

CHD – coronary heart disease

ICD – implantable cardioverter-defibrillator***

SGLT2 inhibitor – sodium-glucose cotransporter 2 inhibitor (ATC A10BK Sodium-glucose cotransporter 2 (SGLT2) inhibitors)

CA – catheter ablation (radiofrequency ablation of arrhythmogenic zones; robotic-assisted radiofrequency ablation of arrhythmogenic zones, cryoablation of arrhythmogenic zones)

AAC – arrhythmia-associated cardiomyopathy

CAG – coronary angiography

CPVT – catecholaminergic polymorphic ventricular tachycardia

LV – left ventricle

LBBB – left bundle branch block

MRI – magnetic resonance imaging

SVT – supraventricular tachycardia

NSVT – non-sustained ventricular tachycardia

ACS – acute coronary syndrome

OMT – optimal medical therapy

RV – right ventricle

PVS – programmed ventricular stimulation (cardiac pacing)

RCT – randomized controlled trial

SQTS – short QT syndrome

CPR – cardiopulmonary resuscitation

HF – heart failure

SHD – structural heart disease

CRT – cardiac resynchronization therapy (implantation of a triple-chamber pacemaker (resynchronization therapy))

CRT device – implantable device for cardiac resynchronization therapy (triple-chamber pacemaker, also known as a triple-chamber (biventricular) implantable cardioverter-defibrillator***)

CVD – cardiovascular disease

LQTS – long QT syndrome

LCE – level of confidence of evidence

SVT – sustained ventricular tachycardia

SMVT – sustained monomorphic ventricular tachycardia

GRS – grade of recommendation strength

EF – ejection fraction

VF – ventricular fibrillation

FC – functional class

Holter ECG – Holter electrocardiogram monitoring (ambulatory cardiac rhythm monitoring)

CHF – chronic heart failure

PCI – percutaneous coronary intervention (transluminal balloon angioplasty and stenting of coronary arteries)

HR – heart rate

ECV – electrical cardioversion (external electrical cardioversion (defibrillation))

ECG – electrocardiography

ECMO – extracorporeal membrane oxygenation

EchoCG – echocardiography

NYHA – New York Heart Association

QTc – corrected QT interval

** – the drug is included in the list of vital and essential drugs

*** – medical device implanted when providing medical care under the state guarantee program for free medical care to citizens

# – medicinal product for medical use used inconsistently with the indications for use, contraindications, routes of administration, and doses contained in the instructions for use of the medicinal product

Terms and Definitions

Instrumental diagnostics – diagnostics using various devices, apparatus, and instruments for patient examination [1, 2].

Outcome – any possible result arising from the exposure to a causal factor, prophylactic or therapeutic intervention, or any established changes in health status occurring as a consequence of an intervention [3].

Conflict of interest – a situation in which a medical or pharmaceutical worker, in the exercise of their professional activities, has a personal interest in obtaining material gain or other advantage, either personally or through a representative, which influences or may influence the proper performance of their professional duties due to a contradiction between the personal interest of the medical or pharmaceutical worker and the interests of the patient [2].

Medical intervention – a set of medical examinations and/or medical procedures, as well as artificial termination of pregnancy, performed by a medical worker or other employee authorized to engage in medical activities, affecting a person's physical or mental state and having a prophylactic, diagnostic, therapeutic, rehabilitative, or research orientation [2].

Medical worker – an individual who has medical or other education, works in a medical organization whose job (official) duties include the performance of medical activities, or an individual who is an individual entrepreneur directly engaged in medical activities [2].

Patient – an individual to whom medical care is provided or who applies for medical care regardless of the presence of a disease and their condition [2].

Working group for the development/updating of clinical guidelines – a team of specialists working together and in coordination to develop/update clinical guidelines and bearing joint responsibility for the results of this work.

Condition – changes in the body arising from exposure to pathogenic and/or physiological factors and requiring medical care [2].

Syndrome – a stable set of symptoms with a unified pathogenesis [4]. The term "syndrome" is traditionally used for a number of conditions where the etiology and pathogenesis are already known, although the term "disease" would be more appropriate. For example, Brugada syndrome, long QT syndrome, and several others.

Structural heart disease – this term applies to adult and pediatric populations and includes coronary artery disease, all types of cardiomyopathies (DCM, HCM, restrictive cardiomyopathy, ARVC), valvular and congenital heart defects [5], as well as the presence of marked LV hypertrophy (according to some data, marked hypertrophy is characterized by an LV lateral wall or interventricular septum thickness ≥ 14 mm in adults, or > 2 z-scores in children [6] according to echocardiography and/or cardiac MRI; however, members of the clinical guidelines working group consider it appropriate for the attending physician to interpret the degree of marked left ventricular myocardial hypertrophy independently due to the lack of conclusive scientific data).

Thesis-recommendation – a statement reflecting the procedure and correctness of performing a particular medical intervention with proven efficacy and safety.

Level of Evidence (LoE) – the degree of certainty that the found effect of a medical intervention is true [7].

Level of recommendations confidence (LRC) – the degree of certainty in the reliability of the intervention effect and in the fact that following the recommendations will bring more benefit than harm in a specific situation [7].

Interventional treatment – a method of treating diseases through minimally invasive intervention, without incisions and tissue joining or with minimal tissue damage. With respect to the treatment of cardiac arrhythmias, interventional treatment most often refers to catheter destruction (ablation) of the arrhythmia substrate/focus, and the placement of endocardial leads for cardiac pacing.

Surgical treatment – a method of treating diseases through the division and joining of tissues during a surgical operation.

ESC – European Society of Cardiology. In the text of these clinical guidelines, recommendations are additionally graded in accordance with ESC guidelines. In accordance with international standards, classes of recommendations and levels of evidence are distinguished.

RSC – Russian Society of Cardiology.

Implantable cardioverter-defibrillator*** (ICD) – an electronic implantable device designed for electrotherapy (cardiac pacing and high-energy shocks) of life-threatening arrhythmias and the prevention of cardiac arrest.

ICD programming (selection of operating parameters for a permanent implantable antiarrhythmic device; programming of a permanent implantable antiarrhythmic device; testing the status of a permanent implantable antiarrhythmic device) – interrogation of the ICD with retrieval from its memory of stored cardiac electrical signals, other information about cardiac rhythms, checking and adjusting pacing and defibrillation parameters, as well as other parameters provided in a specific device. A specialist performing the programming of a permanent implantable antiarrhythmic device (pacemaker, ICD, CRT, etc.) must have specific knowledge about the operation of such devices and experience in their adjustment (programming).

Appropriate ICD shock – high-energy electrotherapy (shock) delivered by the ICD to terminate true ventricular tachycardia (VT) and ventricular fibrillation (VF).

Inappropriate ICD shock – high-energy electrotherapy (shock) delivered by the ICD when device algorithms discriminated (identified) electrogram signals as VT, while the true cause of the detected signals is another etiology, such as SVT, electrical signal noise due to lead fracture, double-counting due to detection of T waves along with QRS, etc. The term is not ideal because, from the perspective of ICD operating algorithms, the delivery of a shock is motivated by the received signals. One-third of the experts involved in the preparation of these guidelines consider "unwarranted shock" to be a more adequate term, but "inappropriate" is well-established in Russian-language literature and is used below in this document. Another term should be distinguished – "unnecessary ICD shock" – a situation where VT termination could have occurred spontaneously, but the programmed algorithm in the ICD delivers a shock prior to spontaneous VT termination; this also applies to situations where VT could be terminated by painless pacing, but the ICD program delivers a shock instead.

Cardiac resynchronization therapy (CRT) (implantation of a triple-chamber pacemaker (resynchronization therapy)) – a method of treating chronic heart failure in the presence of intraventricular conduction disturbances (most commonly left bundle branch block), which is carried out by resynchronizing heart contractions using a triple-chamber (biventricular) implantable cardioverter-defibrillator***. Such systems typically include a right atrial lead, a right ventricular lead, and a left ventricular lead. Leads may be implanted transvenously, surgically, or via thoracotomy.

Holter ECG monitoring (Holter heart rhythm monitoring) is a diagnostic method that provides continuous ECG recording using a portable device (monitor), tracking changes in heart function over an extended period (18 hours or more) during normal daily activity.

Catheter ablation (CA) of arrhythmias (radiofrequency ablation of arrhythmogenic zones; robot-assisted radiofrequency ablation of arrhythmogenic zones; cryoablation of arrhythmogenic zones) is an interventional catheter procedure using specialized catheters inserted into the heart chambers via blood vessels or into the pericardial sac, which involves delivering energy to a myocardial site to eliminate heart rhythm disorders (arrhythmias). Radiofrequency energy is most commonly used for CA (radiofrequency ablation), though other types of energy—such as laser or ultrasound—may also be employed.

1. Brief information on the disease or condition

1.1 Definition of the disease or condition

Ventricular arrhythmias (VA) or ventricular rhythm disorders – a general term for heart rhythm disturbances where the source of ectopic activity or the re-entry circuit is located below the bundle of His, i.e., in its branches, the Purkinje network, or the ventricular myocardium.

Ventricular premature complex (VPC) – a premature (relative to the baseline rhythm) electrical activation of the heart with a widened QRS complex (QRS duration ≥ 120 ms), a T wave discordant to the main deflection of the ventricular complex, and the absence of a P wave preceding the ventricular complex.

Monofocal or monomorphic VPCs – VPCs with a single QRS morphology.

Multifocal or polymorphic VPCs – VPCs with varying QRS morphology.

VPCs with a short coupling interval – VPCs that fall on the T wave of the preceding conducted beat.

Ventricular tachycardia – ≥ 3 consecutive beats at a rate greater than 100 bpm originating from the ventricles, regardless of atrial and AV nodal conduction [8].

Accelerated idioventricular rhythm – ≥ 3 consecutive complexes with a rate > 40 bpm and < 100 bpm originating from the ventricles.

Non-sustained ventricular tachycardia (NSVT) – ventricular tachycardia lasting less than 30 seconds and terminating spontaneously.

Sustained ventricular tachycardia – VT lasting ≥ 30 seconds or requiring intervention for termination.

Monomorphic VT – VT characterized by identical QRS complex configurations.

Polymorphic VT – VT with an unstable, changing QRS complex configuration.

Bidirectional VT – alternation of the frontal QRS axis from beat to beat (observed in catecholaminergic polymorphic VT, Andersen-Tawil syndrome, digitalis toxicity, and acute myocarditis).

Torsades de pointes – torsades de pointes tachycardia, a subtype of polymorphic VT associated with prolonged QT interval duration, featuring continually changing QRS complexes that resemble a sinusoidal wave around the baseline ECG isoelectric line.

Electrical storm – three or more episodes of VT within 24 hours, with an interval of at least 5 minutes between episodes, requiring either antitachycardia pacing or electrical cardioversion/defibrillation.

Ventricular flutter – rhythmic, high-amplitude, widened electrical ventricular deflections at a rate exceeding 250 bpm, with T waves being indistinguishable.

Ventricular fibrillation – chaotic electrical activity presenting as polymorphic oscillations that constantly vary in configuration, amplitude, duration, and frequency, with a range of 300 beats/min or higher.

Frequent ventricular premature beats – an ectopic complex burden of > 10% of total heart beats according to 24-hour Holter ECG monitoring, which is important for predicting the risk of arrhythmia-induced cardiomyopathy (AIC). For patients with acute myocardial infarction, premature beats > 10 per hour are considered "frequent," which has prognostic significance for life-threatening ventricular tachyarrhythmias.

Sudden death – an unexpected fatal event, non-traumatic in origin, occurring within 1 hour of symptom onset in a previously healthy individual. If the death is unwitnessed, sudden death is diagnosed if the victim was in a stable condition 24 hours prior to death.

Sudden cardiac death (SCD) – a term used when sudden death occurs in a subject with a known congenital or acquired potentially fatal heart disease during life, or when cardiovascular pathology is identified at autopsy and could be the cause of death, or when no obvious extracardiac causes of death are found at autopsy, and an arrhythmia is the most likely cause of death.

Sudden cardiac arrest (SCA) – an unexpected cessation of circulation occurring within 1 hour of the onset of acute symptoms, which was reversed by successful resuscitation measures (e.g., defibrillation). In the International Classification of Diseases-10, it is designated as I.46 "Cardiac arrest" and I.46.0 "Cardiac arrest with successful resuscitation".

Sudden unexplained death – unexplained sudden death occurring in a person older than 1 year of age.

Sudden infant death syndrome – unexpected, non-violent death of a previously considered healthy infant under one year of age, for which history findings are inadequate to explain the cause of death, and toxicological and pathomorphological examinations yield negative results.

Sudden arrhythmic death syndrome – unexplained sudden death occurring in a person older than 1 year of age, with negative results from toxicological and pathomorphological examinations.

Idiopathic ventricular arrhythmia – when clinical evaluation of the patient fails to identify diseases potentially associated with ventricular arrhythmia.

Primary prevention of SCD – measures aimed at reducing the risk of SCD in individuals who have an elevated risk of SCD but no history of life-threatening arrhythmias or aborted cardiac arrest.

Secondary prevention of SCD – measures aimed at reducing the risk of SCD in individuals with a history of life-threatening arrhythmias or aborted cardiac arrest.

Brugada syndrome – a hereditary channelopathy syndrome characterized by a typical ECG pattern and a high risk of ventricular fibrillation and SCD.

Catecholaminergic polymorphic ventricular tachycardia (CPVT) – a rare hereditary channelopathy characterized by a malignant course of adrenergically induced bidirectional and polymorphic ventricular tachycardia.

Neuromuscular diseases – a group of hereditary diseases characterized by progressive primary involvement of nerve fibers (neuropathies) or skeletal muscle (myopathies and myodystrophies). Cardiac muscle and conduction system involvement is variable and does not correlate with the severity of neurological and myopathic symptoms.

Non-compaction myocardium – a specific type of cardiomyopathy characterized by prominent trabeculation and deep intertrabecular recesses in the left and/or right ventricle, frequently accompanied by a thin compacted epicardial myocardial layer. The diagnosis is established based on echocardiographic and/or MRI criteria (ratio of non-compacted to compacted layer thickness > 2). Many patients with left ventricular non-compaction are completely asymptomatic, but associations with all known types of cardiomyopathies are possible, progressing to heart failure, thromboembolism, arrhythmias, or history of SCD.

QT interval – reflects ventricular electrical systole (time in milliseconds from the onset of the QRS complex to the end of the T wave). Its duration depends on gender (QT is longer in women), age (QT prolongs with age), and heart rate (inversely proportional). For an objective assessment of the QT interval, the heart rate-corrected QT interval (QTc) is currently used, determined by Bazett's and Fridericia's formulas. Normally, the QTc is 340–480 ms for women and 340–460 ms for men. Values greater than 500 ms are considered pathological.

Long QT syndrome (LQTS) – the most common hereditary channelopathy syndrome (prevalence 1:3000 – 1:2500 of the population), characterized by prolongation of the QT interval and life-threatening ventricular arrhythmias, mostly provoked by adrenergic activation.

Short QT syndrome (SQTS) – a rare hereditary channelopathy characterized by shortening of the QT interval and an increased risk of life-threatening arrhythmias.

Experienced center (in the context of interventional procedures) – a medical institution or a department of an institution where staff specialists have significant experience in managing patients with cardiac arrhythmias, and where catheter ablations of tachyarrhythmias, such as atrial fibrillation, atypical atrial flutter, post-infarction ventricular tachycardias, ventricular tachycardias in arrhythmogenic right ventricular cardiomyopathy (ARVC), dilated cardiomyopathy (DCM), and others, are performed on a regular basis.

Experienced specialist (in the context of interventional procedures) – a medical specialist with significant experience in managing patients with cardiac arrhythmias, such as atrial fibrillation, atypical atrial flutter, and ventricular tachycardias, who regularly performs catheter ablations of the tachyarrhythmia substrate, such as atrial fibrillation, atypical atrial flutter, post-infarction VTs, VTs in ARVC, DCM, and others.

Pathogenic and likely pathogenic genetic variant – The American College of Medical Genetics and Genomics (ACMG) proposed a framework for interpreting the association between genetic variants and disease causation by standardizing them into classes. Genetic variants that are proven causes of disease have pathogenicity class V (commonly written as Pathogenic, Path, P). Genetic variants that are highly likely to be causes of disease have pathogenicity class IV (commonly written as Likely pathogenic, LikelyPat, LP).

Mutations – the term is used in this document to refer to pathogenicity class IV and V variants.

Genetic variant of unknown clinical significance – an alteration in the gene deoxyribonucleic acid (DNA) sequence whose effect on human health is unknown; a pathogenicity class III variant according to the ACMG (2015) criteria [9].

Arrhythmia-induced cardiomyopathy (AIC) – dilation of the ventricular chamber(s) and a decrease in ventricular systolic function most likely caused or exacerbated by a cardiac rhythm disorder, such as frequent VES, incessant/recurrent VT, atrial fibrillation, atrial tachycardia, etc. In many cases, AIC is partially or fully reversible after suppression of the arrhythmia. In addition to rhythm rate and the proportion of ectopic heart beats, the width of ectopic QRS complexes is also important for the risk of developing AIC.

1.2 Etiology and pathogenesis of the disease or condition (group of diseases or conditions)

The main mechanisms of VA are:

- re-entry mechanism (circus movement of the excitation wave);

- abnormal automaticity;

- triggered activity induced by early or delayed afterdepolarization;

- accelerated normal automaticity.

The creation of conditions for the occurrence of the re-entry phenomenon in the ventricular myocardium—in the form of zones of slowed conduction and areas of heart muscle with different refractory periods—is usually associated with pathological changes in the myocardium. Therefore, paroxysmal VT in the vast majority of cases complicates the course of severe heart diseases, such as CAD (especially in the presence of post-infarction scars and chronic left ventricular aneurysm), inflammatory myocardial diseases, cardiomyopathies (DCM, HCM, ARVC, etc.), and infiltrative myocardial diseases. Cardiac arrest as a mechanism of SCD occurs in the absolute majority of cases (more than 80%) as a result of VF or VT, and significantly less often (less than 20%) as a result of asystole [10].

1.3 Epidemiology of the Disease or Condition

1.3.1 Incidence of sudden cardiac death

SCD accounts for about 50% of all cardiovascular deaths, and in half of the cases, SCD is the first manifestation of the disease; the most frequent mechanism of SCD is ventricular tachyarrhythmia [11, 12, 13, 14, 15, 16].

Ideally, cases suspected of SCD should be registered and subjected to autopsy, which will reliably rule out non-cardiac causes of sudden death. SCD as an irreversible outcome and the result of sudden cardiac arrest accounts for up to 50% of all deaths in individuals aged 35–50 years, predominantly males, although recently there has been a trend toward an increase in the proportion of females, as well as adolescents and young adults. The risk of SCD is higher in men and increases with age due to the higher prevalence of CAD among older people [17].

SCD accounts for half of all deaths from cardiovascular diseases, with an estimated 7 million people dying suddenly worldwide [18, 19].

Data on the prevalence of SCD in Russia are limited, partly due to the specific features of SCD registration in different countries. The proportion of SCD across all age groups was 49.1% (15,420 out of 31,428 autopsies, or 123.3 per 100,000 population per year). Meanwhile, the prevalence of SCD at ages 1 to 45 years was 27.5% (2,790 out of 10,132 autopsies) [20]. However, values of 200–250 thousand people per year appear closer to reality [21].

1.3.2 Causes of sudden death across different age groups

The number of SCD cases increases with age. In infancy and childhood, SCD is 1 per 100,000 person-years. In middle age (5th–6th decades of life), the incidence of SCD is about 50 per 100,000 person-years [22, 23, 24], reaching an incidence of 200 per 100,000 person-years by the 8th decade of life [12].

At any age, the incidence of SCD is higher among men than among women, even after adjusting for risk factors such as CAD [16, 25, 26, 27].

In Europe, SCD accounts for about 10–20% of all deaths [28, 29]. The epidemiology of SCD in Europe is closely linked to CAD, which accounts for 75–80% of SCD cases [30]. Although the prevalence of CAD has not decreased, there has been a significant reduction in CAD mortality. Statistically, the incidence of SCD is decreasing [30], but the proportion of SCD out of total cardiovascular deaths is likely increasing [31, 32].

Regular physical activity has undeniable benefits for the cardiovascular system. In certain populations (especially middle-aged men), SCD may occur during or immediately after super-intense physical exertion [33], which suggests CAD plays a role as the most common cause of SCD [34].

Heart diseases associated with SCD vary by age. Annually, 300,000 people in Europe experience out-of-hospital cardiac arrest [17, 35]. Primary electrical disorders, cardiomyopathies, as well as myocarditis and coronary artery anomalies predominate in young individuals [17, 34, 35].

During the fourth decade of life, half of SCD cases are associated with CAD, especially acute coronary syndrome [36, 37].

In older adults, chronic structural diseases predominate (acute and chronic forms of CAD, valvular heart disease, heart failure), whereas in individuals under 50 years of age, hereditary electrical diseases or structural non-ischemic diseases may cause more than 50% of SCD cases [34].

1.3.3 Population and individual risk prognosis

Overall cardiovascular risk assessment should be performed in accordance with the 2017 cardiovascular prevention guidelines [38]. Several studies have shown that there is a genetic predisposition to sudden death during acute ischemia [39, 40]. It is important to identify relatively small high-risk subgroups in the general population in whom SCD may be the first manifestation of the disease. Recently, US scientists have proposed novel population-based SCD risk stratification models [41]. There are no clear data supporting the benefit of mass screening programs in the general population to prevent SCD [42].

For decades, researchers have hypothesized a wide range of SCD "indicators" and "markers," especially in the presence of CAD. Several non-invasive risk markers have been proposed (including late potentials, heart rate variability, repolarization dynamics, and baroreflex sensitivity) [43]. However, despite promising initial findings, these "predictors" have not yet impacted clinical practice. Left ventricular ejection fraction (LVEF) is used in combination with the New York Heart Association (NYHA) functional class only to determine indications for ICDs for primary prevention of SCD in chronic CAD and DCM. Risk stratification schemes and calculators have been developed for inherited arrhythmogenic diseases such as HCM, ARVC, and lamin A/C (LMNA) cardiomyopathy [44, 45].

Sudden cardiac death risk calculators

Numerous SCD risk calculators have been proposed for adults and children [46, 47]. The evolution of SCD prediction over recent decades has included the establishment of standards for model development, their validation (internal and external), followed by the publication of papers on SCD prediction models [48, 49]. Typical shortcomings in the development and validation of risk calculators include, among other things, the use of historical datasets not representative of modern patient cohorts, missing values, composite endpoints with composite events of varying clinical significance, lack of external validation, and lack of calibration.

Risk calculators are recommended for use by the European Society of Cardiology (validated in the European patient population) and can be used in Russia for clinical decision support.

1.4 Features of Coding the Disease or Condition

I46. Cardiac arrest

I46.0. Cardiac arrest with successful resuscitation

I46.1. Sudden cardiac death, so described

I46.9. Cardiac arrest, unspecified

I47.0. Re-entry ventricular arrhythmia

I47.2. Ventricular tachycardia

I47.9. Paroxysmal tachycardia, unspecified

I49.0. Ventricular fibrillation and flutter

I49.3. Premature ventricular depolarization

I49.4. Other and unspecified depolarization

I49.8. Other specified cardiac arrhythmias

I49.9. Cardiac arrhythmia, unspecified

1.5 Classification of the disease or condition

Classifications of ventricular arrhythmias (VAs) based on VA type and number were formulated more than 40–50 years ago. However, due to significant developments in VA treatment over the past two decades, the introduction of personalized patient approaches based on modern diagnostic methods, and improved assessment of prognosis and complication risks, a more up-to-date systematization of VA data is required for clinical practice. Many VA parameters (e.g., arrhythmia symptomatology, arrhythmia burden, electrophysiological mechanism, and arrhythmogenic focus localization) are almost never reflected in clinical diagnoses, yet they are of paramount importance in determining treatment strategies and methods for arrhythmia suppression.

The current version of the guidelines proposes a new expanded version of the VA classification, which systematizes important characteristics of the arrhythmia that influence prognosis and treatment. Furthermore, it designates VA characteristics that should be indicated in the diagnosis or diagnosis description in medical documentation (designated as a "key characteristic"), as well as VA characteristics that are not mandatory in the diagnosis, but are desirable following additional patient evaluation or an electrophysiological study.

This classification was unanimously approved by all members of the working group for these clinical guidelines, approved by the Clinical Guidelines Committee of the Russian Society of Cardiology on March 23, 2023, and can be recommended for use in daily clinical practice.

Table 1. 2023 Russian Society of Cardiology Classification of Ventricular Arrhythmias (RSC-VA-23)

Examples of diagnosis formulation:

1. ICD-10 diagnosis: I49.3 Premature ventricular depolarization.

Arrhythmia diagnosis description: Idiopathic symptomatic frequent (> 10% of ventricular beats) monomorphic isolated premature ventricular complexes originating from the right ventricular outflow tract.

2. ICD-10 diagnosis: I25 Chronic ischemic heart disease. I25.2 Old myocardial infarction. I47.2 Ventricular tachycardia. I46.1 Sudden cardiac death, so described.

Arrhythmia diagnosis description: Paroxysmal symptomatic (cardiac arrest dated 01.02.2023) rapid sustained monomorphic left ventricular tachycardia in the setting of post-infarction cardiosclerosis.

The Lown B./Wolf M. and Ryan M. ventricular arrhythmia classifications remain relevant for risk stratification in the early and delayed periods following myocardial infarction [50, 51].

1.6 Clinical presentation of the disease or condition

Clinical manifestations of ventricular tachyarrhythmias can vary significantly, ranging from absolute asymmetry to palpitations, chest discomfort, retrosternal pain, dyspnea, dizziness, syncopal episodes, and sudden cardiac death. Palpitations, presyncope, and syncope are the three most important symptoms that require a thorough history-taking and additional workup to rule out ventricular tachyarrhythmias.

2. Diagnostics, medical indications and contraindications for diagnostic methods

Diagnostic criteria

Ventricular arrhythmias (VAs) or ventricular rhythm disorders are a general term for heart rhythm disturbances where the source of ectopic activity or re-entry circuit is located below the bundle of His, i.e., in its branches, the Purkinje network, or the ventricular myocardium.

The primary diagnostic methods for ventricular arrhythmias are ECG and Holter ECG monitoring; however, in certain cases, to establish and refine the diagnosis, as well as for the differential diagnosis of wide QRS complex tachycardias, an intracardiac electrophysiological study (EPS) is performed.

General ECG signs for all ventricular arrhythmias include: 1) a wide, deformed QRS complex (≥ 120 ms), which is usually premature, less often timely or escape; 2) absence of a preceding P wave; 3) T wave discordance relative to the main wave of the ventricular complex; 4) presence of fusion complexes. Variants of ventricular arrhythmias and their ECG diagnostic criteria are detailed in section 1.1.

Diagnostic evaluation for suspected ventricular arrhythmias includes the following stages:

- thorough review of complaints, history of present illness, and family history;

- physical examination and general assessment;

- laboratory and instrumental tests: simpler methods at the first stage and more advanced methods at the second stage of evaluation (as indicated);

- post-mortem examination and molecular analysis of sudden cardiac death victims;

- genetic testing;

- imaging modalities and morphological studies.

2.1 Complaints and Anamnesis

ESC IC (LoE C, SoR 5)

Comment. The nature of the clinical symptoms of PVCs, as well as their prognostic significance for the patient's health and life, depends on the manifestations of the extrasystoles themselves, but even more so on the underlying disease causing them. Rare isolated PVCs in individuals without signs of organic heart disease may be asymptomatic or mildly symptomatic, presenting only as a sensation of skipped heart beats. Frequent extrasystoles with periods of bigeminy, especially in patients with impaired cardiac contractility (coronary artery disease, cardiomyopathies, other forms of myocardial damage), in addition to skipped beats, can lead to decreased blood pressure, weakness, dizziness, and the onset or worsening of dyspnea.

• When interviewing a patient with structural heart disease who is at high risk for ventricular arrhythmias, it is recommended to purposefully inquire about symptoms to identify paroxysmal ventricular arrhythmias due to the high probability of their development [50, 51].

ESC IC (LoE C, SoR 5)

Comment. The severity of clinical manifestations depends on the heart rate during the paroxysm, the presence or absence of structural heart disease, and concomitant pathology (e.g., brachiocephalic artery atherosclerosis).

• In order to detect life-threatening conditions in patients with structural heart disease, especially those with a history of myocardial infarction and reduced left ventricular ejection fraction, it is recommended to consider ventricular arrhythmias as one of the probable causes of syncopal episodes [50, 51].

ESC IC (LoE C, SoR 5)

• In order to identify life-threatening conditions during patient interview, it is recommended to consider long QT syndrome (LQTS) and catecholaminergic polymorphic ventricular tachycardia (CPVT) as potential causes of cardiogenic syncope occurring at the peak of physical or emotional exertion, especially in young patients without structural heart disease. Furthermore, specific triggers for LQTS-related syncope such as a sudden loud noise, swimming, or awakening should be taken into account [52, 53].

ESC IB (LoE B, GoR 3)

Comment. When taking the medical history of patients with LQTS, it is recommended to pay attention to the medications the patient is taking, as QT interval prolongation can be induced by many non-cardiological drugs (a regularly updated list is available at https://crediblemeds.org/; current information on drug side effects is available at https://www.drugs.com/).

• In patients with suspected or confirmed ventricular tachyarrhythmias, it is recommended to take a family history aimed at identifying cases of sudden and unexplained deaths (e.g., drowning) among first- and second-degree relatives at a young age to assess the likelihood of genetically determined ventricular arrhythmias [50, 51].

ESC IC (LoE C, SoR 5)

2.2 Physical Examination

• All patients undergoing evaluation should be recommended the following standard measurements to establish the diagnosis of primary and comorbid conditions or to rule out potential triggers of ventricular arrhythmias [50, 54]:

- anthropometric parameters (measurement of height, body weight, body mass index, waist circumference measurement);

- general thermometry and assessment of skin condition;

- assessment for the presence of edema and its distribution;

- measurement of blood pressure in peripheral arteries;

- evaluation of peripheral pulse, including rate and rhythm regularity;

- assessment of jugular venous distension and pulsation, which may indicate venous congestion;

- auscultation of the heart, carotid, renal, and femoral arteries to detect pathological murmurs;

- palpation of the thyroid gland: size, tenderness, mobility.

ESC IC (LoE C, SoR 5)

Comment. In addition to basic parameters, it is recommended to assess specific changes to rule out reversible causes that may potentially be associated with ventricular arrhythmias. Screening for cutaneous manifestations of rare systemic inflammatory (scleroderma, sarcoidosis) and infectious diseases (Chagas disease, borreliosis, etc.) is important [55]. Patients with LQTS and CPVT are characterized by bradycardia. In rare cases, examination of patients with congenital LQTS or arrhythmogenic right ventricular cardiomyopathy (ARVC) may reveal sensory organ anomalies (congenital deafness) and musculoskeletal abnormalities (syndactyly).

• During the physical examination of patients with paroxysmal heart rhythm disorders, it is recommended to identify signs of hemodynamic instability (decreased blood pressure) in order to determine the appropriate medical care pathway [56, 57].

ESC IC (LoE C, SoR 5)

Comment. In the vast majority of ventricular arrhythmias, physical examination findings between paroxysms are unremarkable. Premature heartbeats (extrasystoles) may be noted when palpating the pulse, measuring blood pressure, or auscultating the patient's heart.

2.3 Laboratory Diagnostics

As part of the evaluation, it is advisable to perform a standard laboratory minimum, including a complete blood count and a general clinical blood chemistry panel to determine the overall cardiovascular risk level, with monitoring of additional parameters to confirm or exclude transient, correctable disturbances that are potentially significant for the occurrence of ventricular arrhythmias.

All patients with ventricular tachyarrhythmias (VTA) as part of the initial evaluation and during dynamic follow-up, to rule out comorbid conditions and determine treatment tactics, should undergo a biochemical blood test including: sodium and potassium levels, creatinine level, glucose level, total protein level, total bilirubin level, uric acid level, C-reactive protein level, aspartate aminotransferase and alanine aminotransferase activity, blood cholesterol and lipoprotein levels, and triglyceride levels [58, 59, 60, 61, 62].

RSC IIaC (LOC C, LOE 5)

• In all cases in adult patients with VTA, it is recommended to perform an evaluation to confirm or exclude transient (modifiable) factors significant for the occurrence of VA (use of cardiac glycosides, AAP (C01B Antiarrhythmic drugs, classes I and III), serum potassium and magnesium levels, signs of acute MI, hyperthyroidism, etc.) [59, 63, 64].

ESC IC (LoE C, SoR 5)

• Patients with significant QT interval prolongation on ECG are recommended to undergo a set of tests to identify transient causes: thyroid-stimulating hormone blood test in adults to detect hypothyroidism and hyperthyroidism, hypokalemia, hypocalcemia, drug use, metabolic disorders, various diets, etc.) [61, 62, 63, 64, 65].

ESC IC (LoE C, GoR 4 – for adults, LoE C, GoR 5 – for children)

• In patients with a Brugada pattern on the ECG, it is recommended to exclude transient causes leading to such ECG changes (e.g., acute coronary syndrome, pulmonary embolism, pericarditis, etc.) [50, 51].

LoE C, GoR 5

2.4 Instrumental Diagnostics

Screening of patients with suspected or proven VTA

Standard 12-lead ECG can help identify signs of hereditary diseases associated with VA and SCD, such as channelopathies (LQTS and SQTS, Brugada syndrome, CPVT) and cardiomyopathies (ARVC and HCM). ECG signs such as bundle branch block, AV block, ventricular hypertrophy, and a Q wave characteristic of CAD or infiltrative cardiomyopathy indicate structural heart disease. Electrolyte disturbances and the effects of various drugs can lead to repolarization abnormalities and/or QRS complex prolongation.

Among instrumental diagnostic methods, echocardiography is most commonly used; compared to cardiac MRI and CT, it is less expensive, more accessible, and allows highly accurate diagnosis of myocardial, heart valve diseases, or congenital heart defects associated with VA and SCD [66]. In addition, in most patients, it makes it possible to assess LV systolic function and regional myocardial wall motion.

• 12-lead ECG recording is recommended for all patients with cardiovascular diseases during evaluation to detect VA [50, 740].

ESC IA (LoE C, GoR 5)

• 12-lead ECG recording and electrocardiographic monitoring are recommended for all patients with suspected VA to confirm or rule them out [50, 740].

RSC IC (LoE C, GoR 5)

Comment. Electrocardiographic monitoring is advisable to detect VA and evaluate the outcomes of medical and surgical treatment. Electrocardiographic monitoring makes it possible to correlate patient symptoms with registered rhythm disorders, assess the clinical and electrocardiographic characteristics of VA (types, burden, arrhythmia morphology, duration and recurrence of VT, ventricular rate during VT, association with triggering factors).

• Exercise ECG is recommended for patients if it is known or suspected that VA is provoked by physical exertion, to establish the diagnosis, determine prognosis, evaluate the efficacy of drug therapy or ablation [67].

ESC IA (LoE C, GoR 5)

Comment. This examination must be performed by qualified personnel in a facility equipped in accordance with the requirements.

• Echocardiography to assess LV and RV function and detect ARVC is recommended for all patients with suspected or proven sustained ventricular arrhythmias, or those at high risk for severe ventricular arrhythmias or SCD [68, 69, 741].

ESC IA (LoE C, SoR 5)

Comment. Echocardiography should be performed in all patients presenting with ventricular arrhythmias and suspected ARVC, as well as in patients at high risk for ventricular arrhythmias or SCD, for example, those with dilated, hypertrophic, or right ventricular cardiomyopathy, survivors of acute MI, or relatives of patients with hereditary conditions carrying a high risk of SCD.

• Stress testing (ECG / stress echocardiography / myocardial perfusion single-photon emission computed tomography with functional tests) is recommended for adult patients with ventricular arrhythmias who have an intermediate or high probability of CAD based on age or symptoms, with the aim of provoking ischemic changes or ventricular arrhythmias, as well as to clarify the diagnosis and prognosis in the presence of exercise-induced sustained ventricular arrhythmias or suspected such pathology, including CPVT [67, 68, 69].

ESC IB (Level of Evidence C, Grade of Recommendation 5)

Comment. Some patients are indicated for stress echocardiography (pharmacological or exercise stress), including patients in whom ventricular arrhythmias may be provoked by ischemia, as well as those who cannot tolerate physical exertion or have resting ECG changes that limit the accuracy of ECG for detecting ischemia.

• Cardiac MRI with contrast enhancement or ECG-synchronized cardiac computed tomography angiography in patients with ventricular arrhythmias is recommended to obtain detailed information on LV and RV function and/or structural heart changes in cases where echocardiography does not provide definitive information [8, 51].

ESC IIa B (LoE C, GoR 5)

Comment. The quality of almost all imaging modalities is affected by frequent premature ventricular contractions. ECG gating, additional sequential breath-holds, and the use of beta-blockers to lower heart rate can improve image quality [8].

• In cases of rare symptoms (e.g., syncope) and the inability to capture an episode during ECG monitoring, the use of an implantable cardiac monitor*** is recommended to detect potential transient arrhythmias capable of causing such symptoms [70, 71].

ESC IA (LOCR C, LOE 4)

Comment. The type of ECG monitoring device and the duration of recording should correspond to the frequency of clinical events. 24–72-hour Holter monitoring is suitable for nearly daily arrhythmias, whereas for rare events, longer ECG recording is advisable: 5–7 day ECG monitoring for weekly events, and an implantable cardiac monitor*** for events occurring several times a year or less frequently.

Invasive diagnostic methods

ESC IIaC (LoE C, GoR 4)

ESC IIaC (LoE C, GoR 5)

Intracardiac electrophysiological study (EPS) with programmed ventricular stimulation is used to assess ventricular tachycardia inducibility, map potential ablation targets, assess the risk of recurrent VT or SCD, identify the causes of loss of consciousness potentially related to rhythm disorders, and determine indications for an implantable cardioverter-defibrillator*** (ICD).

• In patients with characteristic clinical manifestations but no documented ECG during the episodes, as well as in cases where the diagnosis cannot be definitively established based on an ECG recorded during a paroxysm, EPS is recommended for VT induction and diagnosis verification [50, 51].

ESC IB (Level of Evidence C, Grade of Recommendation 5)

• EPS is recommended for adult patients presenting with syncope and suspected bradyarrhythmia or tachyarrhythmia, taking into account symptoms (e.g., palpitations) or non-invasive test results, particularly in patients with ARVC, for SCD risk stratification and selection of management tactics [74, 75].

ESC IB (LoE C, GoR 4)

Comment. Syncope is an unfavorable sign in patients with syncope of suspected cardiac origin (SSCO), especially with pronounced LV dysfunction. The presence of nonsustained ventricular tachycardia (NSVT) according to Holter ECG monitoring, syncope, and SSCO strongly indicates the presence of inducible VT. When syncopal episodes, heart disease, and reduced LVEF are combined, there is a high frequency of repeated arrhythmia episodes and fatal cases, even when PES gives negative results. PES is advisable to perform in patients with LV dysfunction after a myocardial infarction (LVEF < 40%), but this study is not a sensitive method for patients with non-ischemic cardiomyopathy; moreover, the induction of polymorphic VT or VF, especially with aggressive stimulation, is not a specific marker. In coronary artery disease, the value (predictive accuracy) of diagnostic information obtained during PES can reach 50%.

• PES is recommended for SCD risk stratification in adult patients with Brugada syndrome and ARVC, although the interpretation of the study results requires caution [76, 77, 78].

ESC IB (CQR C, LVE 4 for adults; CQR C, LVE 3 for children)

Comment. The absence of VT or VF induction during the study indicates a favorable prognosis; however, the prognostic significance of VT or VF induction is currently undetermined.

• PES is not recommended for SCD risk stratification in adult patients with congenital long QT syndrome (LQTS) and CPVT [76, 77, 79, 80, 81].

ESC III (CQR C, LVE 4)

Comment. The amount of valuable diagnostic information obtained using PES varies significantly depending on the type and severity of the underlying heart disease, the presence or absence of spontaneous VT, medications taken, the stimulation protocol, and the stimulation site. The highest induction rate and reproducibility of the method are observed in patients who have suffered a myocardial infarction. Diagnostic informativity differs across patient groups and is usually quite low in the absence of syncope and ECG changes [75, 77] and often yields false-negative results [77]. In patients with normal LV function and without syncope, PES may provoke nonspecific tachyarrhythmia.

Provocative tests in the diagnostics of ventricular tachyarrhythmias

Active orthostatic test. Evaluating the dynamics of the QT interval during ECG recording during an orthostatic test has diagnostic significance, making it possible in some cases to identify individuals with LQTS. After assuming an upright position, a moderate increase in sinus rate is observed; in healthy patients, the duration of the QT interval decreases, whereas in patients with LQTS, the duration of the QT interval decreases less significantly, does not change, or increases (this is maximally pronounced in patients with type 1 LQTS). Prolongation of the corrected QT interval (QTc) in orthostasis of more than 499–500 ms is one of the diagnostic criteria [80, 81, 82].

Graded exercise test on a bicycle ergometer or treadmill. Evaluating the duration of the QT interval during the recovery period is the most informative. The dynamics of the corrected QT interval is assessed at baseline, at peak exercise, and at the 4th minute of the recovery period. A QTc interval value ≥ 480 ms at the 4th minute of recovery after the stress test is considered one of the criteria for diagnosing congenital LQTS (a criterion comparable in significance to the presence of T-wave alternans) [81, 82].

2.5 Other Procedures

Molecular genetic testing methods

Medical genetic counseling in facilities with experience in genetic testing and follow-up is necessary for all patients with primary electrical heart diseases (channelopathies) and their relatives, and should include a discussion of the benefits, risks, and limitations of genetic testing. Patients should be fully informed about the meaning and significance of screening, its possible results, their clinical significance, and cardiovascular genetics issues in general. Treatment strategy should not be based solely on the results of genetic testing, but should rely on the results of a comprehensive clinical, instrumental, and genetic evaluation [81, 83, 84].

It is advisable to perform genetic testing in patients with a potential primary electrical heart disease (channelopathy) only in combination with appropriate medical genetic counseling [81, 82, 83, 84].

Long QT syndrome (LQTS)

• Molecular genetic testing for mutations in genes with proven causative character for LQTS (KCNQ1, KCNH2, SCN5A, CALM1, CALM2, CALM3) is recommended for diagnostic purposes in all patients with a high probability of a clinical diagnosis of LQTS based on personal and family history, resting ECG, Holter ECG, and exercise test data (Schwartz score in Appendix G1 [83, 84, 85]).

RSC IB (CQR B, LVE 3)

Comment. In patients with a prolonged QT interval and a specific phenotype characteristic of hereditary syndromes, screening for mutations in the corresponding genes should be performed (e.g., KCNQ1 and KCNE1 genes in Jervell and Lange-Nielsen syndrome; CACNA1C gene in Timothy syndrome; KCNJ2 gene in Andersen syndrome; TRDN gene if triadin knockout syndrome is suspected; NAA10 gene in Ogden syndrome) [84, 85, 86].

• Performing comprehensive molecular genetic testing to identify potential mutations in KCNQ1, KCNH2, SCN5A, CALM1, CALM2, CALM3 genes (types 1, 2, and 3 LQTS are the most common forms of the disease) is recommended for the diagnosis of LQTS in all patients with clinical manifestations of LQTS and prolongation of the QTc interval registered on a resting ECG or during provocative diagnostic tests, as well as in all patients without clinical symptoms characteristic of LQTS, when prolongation of the QTc interval > 480 ms in prepubertal age and QTc > 500 ms in adults is registered on the ECG in the absence of other possible causes of QT interval prolongation [82, 83, 86].

ESC IA (LoE B, QoE 3)

Comment. Molecular genetic testing methods are of significant importance in diagnosing LQTS and determining patient prognosis. When performing comprehensive genetic assays, mutations are detected in approximately 75% of patients, so a negative genetic test result does not completely rule out a diagnosis of LQTS. In the case of a negative test for first-line mutations, exome sequencing may be considered to search for the causative variant in the proband.

• Performing a comprehensive molecular genetic study to identify possible mutations in the KCNQ1, KCNH2, and SCN5A genes is recommended for patients without characteristic LQTS symptoms, when QTc interval prolongation > 480 ms in prepubertal age and QTc > 500 ms in adults is registered on the ECG in the absence of other possible causes of QT interval prolongation, for the purpose of diagnosing LQTS [82, 83, 86].

ESC IA (LoE B, QoE 3)

• If a genetic mutation is detected in a patient with LQTS, screening aimed at identifying this mutation is recommended for all close relatives, even in the absence of clinical manifestations and ECG changes characteristic of this disease, to assess individual prognosis [82, 83].

ESC IIaB (Level of Evidence B, Grade of Recommendation 3)

RSC IIb C (CQR C, LVE 5)

• To assess individual prognosis, variant-specific cascade family screening is recommended for relatives of the proband with LQTS, even in the absence of clinical manifestations and ECG changes characteristic of this disease [81, 83].

RSC IC (LoE C, GoR 5)

Comment. Genetic testing to assess prognosis in children who are relatives of a proband with an identified mutation is recommended starting from birth (at any age).

Brugada syndrome

The only gene with proven causality in Brugada syndrome is the SCN5A gene, but mutations in this gene account for only about 20% of cases. Known phenocopies of Brugada syndrome, such as myocardial ischemia, electrolyte disturbances, pulmonary embolism, and drug intoxication, must be ruled out before testing is performed.

• Screening for mutations in the SCN5A is recommended for patients with a type 1 Brugada ECG pattern, either occurring spontaneously or induced by sodium channel blockers, combined with clinical manifestations and/or a positive family history, in order to diagnose Brugada syndrome [85, 86].

RSC IC (Reliability of Evidence B, Level of Evidence 3)

• Variant-specific cascade family screening is recommended for family members of the proband with identified rare genetic variants of classes IV-V of pathogenicity for sudden cardiac death (SCD) risk stratification [85, 86].

RSC IIa C (Reliability of Evidence B, Level of Evidence 3)

ESC IIIC (LoE B, LoR 3)

Catecholaminergic polymorphic ventricular tachycardia (CPVT)

• Molecular genetic testing for mutations in RYR2, CASQ2, CALM1-3, TRDN, TECRL, KCNJ2 is recommended for all patients with CPVT and those whose clinical manifestations are highly likely to be caused by this condition, for diagnostic purposes and individual prognosis refinement [82, 87].

ESC IC (RR S, ELD 5)

Comment. The clinical manifestations of Purkinje fiber-associated polymorphic ventricular tachycardia (SCN5A mutations) and Andersen-Tawil syndrome (KCNJ2 mutations) may also overlap with CPVT; however, the frequency of premature ventricular contractions (PVCs) at rest (outside of catecholaminergic stimulation) in such patients is quite high, which distinguishes these syndromes from true CPVT. Therefore, including the SCN5A gene in the diagnostic panel may also be justified for a number of patients.

• If a pathognomonic genetic mutation is detected in a patient via molecular genetic testing aimed at identifying this mutation, molecular genetic screening is recommended for all first-degree relatives of the patient, even in the absence of clinical manifestations of the disease, for diagnostic purposes and individual prognosis refinement [82, 84].

ESC IC (RR S, ELD 5)

Short QT syndrome

• For patients with suspected short QT syndrome (SQTS), it is recommended to consider comprehensive mutation screening in the KCNH2, KCNQ1, KCNJ2, and SLC4A3 genes to identify and assess individual risks [82].

ESC IC (LoE C, GoR 5)

Comment. The low sensitivity of methods in diagnosing the disease should be taken into account.

• To assess individual prognosis, variant-specific cascade family screening is recommended for relatives of the proband with SQTS, even in the absence of clinical manifestations and ECG changes characteristic of this disease [82].

RSC IIaB (Reliability of Evidence C, Level of Evidence 5)

Arrhythmogenic cardiomyopathy

Arrhythmogenic cardiomyopathy is generally characterized by fibrous or fibrofatty replacement of the myocardium, leading to progressive impairment of contractility (focal/global) and a high frequency of ventricular arrhythmias. Structural changes can affect both the right and left ventricles, and biventricular forms are also known. Three main phenotypes are distinguished: predominantly right ventricular variant ("classical" arrhythmogenic right ventricular cardiomyopathy — ARVC), biventricular variant, and predominantly left ventricular variant (also known as "arrhythmogenic left ventricular cardiomyopathy" — ALVC). Identification of a genetic variant of high pathogenicity classes (Pathogenic/Likely Pathogenic) is a major diagnostic criterion for all types of arrhythmogenic cardiomyopathy, and may be a prerequisite for diagnosing the left ventricular variant of arrhythmogenic cardiomyopathy. The most frequent inheritance pattern of arrhythmogenic cardiomyopathy is autosomal dominant, though a small number of autosomal recessive forms are also known [81, 88, 89, 90].

• Mutation screening in PKP2, DSP, DSG2, DSC2, JUP, TMEM43, PLN, FLNC, DES, LMNA is recommended for all patients with a definitive diagnosis of arrhythmogenic cardiomyopathy established based on current diagnostic criteria. If high-pathogenicity variants are identified, cascade family screening aimed at detecting this mutation is recommended for all close relatives, even in the absence of clinical manifestations of the disease, for diagnostic purposes and individual prognosis refinement [81, 82, 84].

LoE C, GoR 5

• All patients with a probable and possible diagnosis of arrhythmogenic cardiomyopathy established on the basis of modern diagnostic criteria are recommended to undergo mutation screening in PKP2, DSP, DSG2, DSC2, JUP, TMEM43, PLN, FLNC, DES, LMNA genes for diagnostic purposes and individual prognosis refinement [81, 82, 83, 88, 90].

RSC IIaB (Reliability of Evidence C, Level of Evidence 5)

Comment. If variants with a high pathogenicity class are identified, it is advisable to perform cascade family screening aimed at detecting this mutation in all first-degree relatives of the proband, even in the absence of clinical manifestations of the disease.

Pathological anatomical examination and molecular genetic analysis in victims of sudden cardiac death

• Autopsy (A08.30.019 Autopsy) is recommended to determine the causes of sudden death and clarify whether SCD is a consequence of rhythm disorders or other mechanisms (e.g., aortic aneurysm rupture) [82, 91].

ESC IC (LoE C, SoR 5)

• Regardless of the timing of the autopsy, along with the pathological anatomical examination, it is recommended to perform a pathological anatomical examination of myocardial biopsy (surgical) material using electron microscopic methods, including the study of labeled blocks of cross-sections of the myocardium of both ventricles of sufficient representativeness, in order to establish the causes of sudden death [82, 91].

ESC IC (LoE C, SoR 5)

• Postmortem examination of blood samples and other biological fluids of SCD victims (immunocytochemical study of biological material; studies of biological fluids used to examine substance concentrations and enzyme activity in body fluid media; forensic chemical examination (study) of a biological object for the presence of chemical substances) and molecular genetic testing for mutations in genes associated with the risk of SCD are recommended in all cases of unexplained SCD to establish the causes of sudden death [82, 91].

ESC IC (LoE C, SoR 5)

• Postmortem molecular genetic testing for the potential identification of genes potentially associated with the development of congenital heart disease should be considered in all SCD victims for whom channelopathies or cardiomyopathies are likely, in order to establish the causes of sudden death [82, 91].

ESC IIaC (LoE C, SoE 4)

Diagnostic investigations in specific clinical manifestations of VT and/or SCD

The most common manifestation variants of VT and/or SCD are:

- newly diagnosed NSVT and/or PVCs (variants: incidentally detected during examination for another condition, purposefully detected during examination of a patient with characteristic complaints or SCD risk);

- newly onset sustained VT;

- survivor of sudden cardiac arrest (SCA);

- deceased due to SCA.

Incidental detection of non-sustained ventricular tachycardia

In patients with newly documented VA (frequent PVCs, NSVT, SMVT), it is necessary to record a baseline 12-lead ECG, record VA on a 12-lead ECG whenever possible, and perform echocardiography. In case of incidental detection of NSVT, additional ECG examination is required, in particular, 24-hour or longer Holter ECG monitoring (H-ECG).

Newly diagnosed sustained monomorphic ventricular tachycardia

In patients with the first episode of SMVT, the following studies can be performed to identify the etiological cause: programmed ventricular stimulation (PVS), electroanatomical mapping, and mapping-guided biopsy.

Survivor of SCA

In electrically unstable patients after SCA with suspected ongoing myocardial ischemia, coronary angiography (CAG) is indicated. All survivors of SCA should undergo echocardiography to assess cardiac structure and function. The evaluation of an SCA survivor without an obvious extracardiac cause should be performed by a multidisciplinary team of specialists. SCA survivors should undergo brain/chest CT if ECG and echocardiography results fail to reveal a vascular cause of SCA. Upon hospital admission of an SCA survivor, it is advisable to perform a toxicological blood test (immunocytochemical study of biological material; studies of biological fluids used to examine substance concentrations and enzyme activities in body fluid media; forensic chemical examination (study) of a biological object for the presence of chemical substances) and collect a blood sample for molecular genetic testing of mutations in genes associated with the risk of SCD (channelopathy screening). All SCA survivors without a clear cause need coronary artery visualization and late gadolinium-enhanced cardiac MRI (ATC V08CA Paramagnetic contrast media) to assess the structure and function of the heart and cardiac vessels.

Victim of sudden death (SD)

In cases of SD, it is necessary to ascertain the details of the circumstances of death, symptoms preceding death, family history, and review previous medical records. Comprehensive post-mortem autopsy should be pursued in all cases of unexpected SD, especially at the age under 50 years. In cases of SD, it is recommended to preserve biological samples suitable for DNA isolation and consult a cardiologist if a hereditary cause is suspected or the cause of death is undetermined. Following sudden arrhythmic death (SAD), it is advisable to perform post-mortem molecular genetic testing aimed at identifying a primary electrical heart disease when the decedent is young (≤ 50 years) and/or the circumstances and/or family history confirm a primary electrical disease.

Relatives of individuals who died from SAD

Evaluation of family members of those who died from SAD is advisable: for first-degree relatives; for relatives who are predicted mutation carriers based on family history analysis; for relatives with suspicious symptoms; when the decedent was < 50 years of age or if there are other data suggesting a hereditary disease. Family evaluation of an SAD decedent should include genetic testing if post-mortem genetic testing of the decedent revealed a pathogenic mutation.

• In patients with newly confirmed ventricular arrhythmias (frequent VES, NSVT, NSVTA) and suspected ARVC (excluding CHD) after initial evaluation, cardiac MRI is recommended to rule out ARVC [92].

ESC IIaB (LoE C, GoR 4)

• Interrogation (programming) of an existing permanent implantable antiarrhythmic device (pacemaker***, ICD***, or other) or a wearable device (e.g., monitor) with analysis of intracardiac electrogram recordings and/or ECG is recommended in all SCA survivors to diagnose the likely heart rhythm disorder leading to SCA [8].

ESC IB (Level of Evidence C, Grade of Recommendation 5)

• SCA survivors are recommended to undergo repeat 12-lead ECG recording during a stable rhythm (including ECG in high precordial leads), as well as continuous ECG monitoring (e.g., Holter monitoring), to detect signs of myocardial changes and/or rhythm and conduction disturbances [90, 92, 740].

ESC IB (Level of Evidence C, Grade of Recommendation 5)

• Pharmacological testing with sodium channel blockers (class IA, IC antiarrhythmic drugs) (for the potential detection of Brugada syndrome or other electrophysiological abnormalities) and exercise stress testing are recommended for SCA survivors without an apparent underlying cause [93].

ESC IB (LoE C, GoR 4)

• Toxicological testing (studies of biological fluids used to examine substance concentrations and enzyme activities in body fluid media) is recommended in cases of SD with an undetermined cause of death to rule out exposure to harmful substances as the cause of SD [94].

ESC IB (LoE C, GoR 4)

• If a hereditary heart disease is suspected at autopsy, it is recommended to refer first-degree relatives for evaluation to a clinic with the appropriate expertise and capabilities for advanced screening aimed at SCD risk stratification [95].

ESC IB (LoE C, GoR 4)

• In non-autopsy cases of SD where a hereditary heart disease is suspected, it is recommended to refer first-line relatives for cardiac evaluation to a clinic with the appropriate expertise and capabilities for advanced screening aimed at SCD risk stratification [96].

ESC IB (LoE C, GoR 4)

ESC IB (LoE C, GoR 4)

• In families with SAD of undetermined diagnosis following clinical evaluation, it is recommended to monitor the children of the deceased until they reach adulthood for the purpose of SCD risk stratification [98].

ESC IC (Level of Evidence C, Grade of Recommendation 4)

• Pharmacological testing with sodium channel blockers (class IA, IC antiarrhythmic drugs) is recommended in relatives of SAD decedents aged 16 years and older if their baseline evaluation and/or the proband's evaluation results raise suspicion of Brugada syndrome [82, 98].

ESC IIaB (LoE C, SoR 4)

3. Treatment, including drug and non-drug therapies, diet therapy, and pain management

3.1 General principles of patient management during ventricular tachyarrhythmia

3.1.1 Elimination of reversible causes

Reversible causes of ventricular arrhythmias can account for up to 50% of SCDs [98]. However, in most cases, it is difficult to determine the underlying cause of SCD and whether it is reversible. Furthermore, it is crucial to understand that eliminating a reversible cause of ventricular rhythm disturbances may require a considerable amount of time. A comprehensive evaluation of patients with SCD is mandatory if heart disease has not been previously diagnosed or its progression is suspected.

• In cases of suspected drug-induced ventricular arrhythmias, discontinuation of these drugs is recommended [99, 100, 101].

ESC IB (LoE B, GoR 3)

Comment. The arrhythmogenic effect of drugs should be suspected in patients taking medications that can alter the electrical properties of the heart (e.g., cause QRS widening or QT interval prolongation) or contribute to electrolyte imbalance (e.g., thiazide and loop diuretics). In such cases, these drugs must be discontinued, and the electrolyte balance restored; furthermore, the use of QT-prolonging drugs (e.g., class III antiarrhythmic drugs) should be avoided [100, 101, 102]. Refractory, recurrent paroxysms of torsades de pointes VT against the background of drug-induced QT prolongation can be terminated by overdrive transvenous ventricular pacing.

• Patients with ventricular arrhythmias are recommended to undergo diagnosis of reversible causes followed by their correction (e.g., electrolyte imbalance, ischemia, hypoxemia, fever) [100, 101].

ESC I C (LoE C, GoR 4)

Comment. Electrolyte imbalance, particularly hypokalemia, can provoke ventricular arrhythmias, while rapidly developing hyperkalemia can cause asystole [103]. Factors such as bradycardia, ischemia, coronary artery spasm, thrombosis, fever, fasting, and diet may also contribute to the occurrence of ventricular arrhythmias [102]. Emergency correction of these reversible disorders is recommended. Hypomagnesemia and/or hypokalemia may be the cause of polymorphic VT such as TdP. Intravenous administration of #magnesium sulfate** is an effective treatment for TdP even in the absence of hypomagnesemia [8, 104, 105, 106, 107, 108]. Adult doses: 2–4 g slow IV push under blood pressure monitoring. The dose may be increased to 6–10 g in the absence of hypotension. Pediatric doses: 12.5% #magnesium sulfate** solution intravenously slowly at 25–50 mg/kg (not exceeding 2 g) [65, 105, 106, 107, 108].

(See Appendix A, Tables A3.4).

Survivors of SCD with a suspected reversible cause have a high mortality rate [109]. In a recent large observational study [110] of SCD survivors associated with a reversible and correctable cause, subsequent ICD*** implantation was associated with lower all-cause mortality, except for SCD in acute MI. Thus, prophylactic ICD*** implantation is possible taking into account the underlying heart disease and individual risk assessment for life-threatening ventricular arrhythmias.

• If, after a thorough assessment of individual risk for ventricular arrhythmias/SCD, the recurrence of VT/SCD is considered high, patients older than 16 years with a remediable cause of ventricular arrhythmias are recommended to undergo ICD*** implantation despite the possibility of its correction [109, 110, 111].

ESC IIaC (LoE C, GoR 4)

3.1.2 Resuscitation measures

• In cardiac arrest (pulseless VT or VF), immediate performance of cardiopulmonary resuscitation (CPR) protocols is necessary (i.e., unequivocally recommended) [66, 109, 111, 112, 113].

ESC IC (Level of Evidence C, Grade of Recommendation 4)

• In cardiac arrest with shockable rhythms (pulseless VT or VF), the key element of CPR (i.e., explicitly recommended) is emergency electrical cardioversion/defibrillation of the heart [112, 113, 114, 115, 116, 117].

ESC IC (LoE C, SoR 5)

• In VF/pulseless VT, after three ineffective shocks from an implantable cardioverter-defibrillator, intravenous bolus administration of amiodarone** (300 mg for adults) is recommended while continuing CPR to increase the efficacy of resuscitation measures and prevent immediate recurrences of VT/VF [111, 118, 119, 120].

ESC IА (LOCR B, LOE 2)

Comment. Administration of an additional 150 mg of amiodarone** is recommended after 5 ineffective shocks from the cardioverter-defibrillator. #Amiodarone** doses for children [118]: IV push 5 mg/kg over 15–20 min., followed by continuous IV infusion: 1 mg/min. for 6 h, 0.5 mg/min. for 18 h (up to 1200 mg per day) (See Appendix A, Tables A3.2 and A3.4).

• Intravenous (IV) administration of lidocaine** while continuing CPR is recommended in case of defibrillation failure or continuous recurrence of arrhythmia to increase the chances of terminating VF and preventing immediate recurrences of VT/VF if amiodarone** is unavailable [102, 117, 119, 120, 121].

ESC IIaB (LoE B, GoR 2 for adults; LoE C, GoR 5 for children)

Comment. Drug doses for adults and children are specified in Appendix A3, Tables A3.2 and A3.4].

ESC IIbA (LoE B, GoR 2 for adults; LoE C, GoR 5 for children)

Comment. The drug is administered to stimulate peripheral vasoconstriction, centralize circulation, and improve cerebral and myocardial perfusion. According to clinical studies, higher doses of the drug do not offer an advantage over the standard 1-mg dose. The timing of the first #epinephrine** dose depends on the cardiac rhythm associated with cardiac arrest:

- for rhythms amenable to defibrillation or cardioversion, the first dose of #epinephrine** is administered after three ineffective shocks from the cardioverter-defibrillator;

- for rhythms not amenable to shock therapy (pulseless electrical activity and asystole), the first dose of #epinephrine** is administered immediately after establishing intravenous access. Drug administration must not interrupt CPR or delay interventions such as defibrillation or cardioversion.

• Emergency electrical cardioversion is recommended for VT accompanied by acute hemodynamic instability (symptomatic arterial hypotension, syncope/presyncope, signs of acute myocardial ischemia, pulmonary edema/acute HF) [8, 126, 127].

ESC IA (LoE C, SoR 5)

3.1.3 Termination of sustained monomorphic ventricular tachycardia

The management of patients with sustained VT should be based on its etiology and clinical presentation. Appendix B, Figure 1 presents the emergency care algorithm for regular (rhythmic) wide-complex tachycardia. Drug doses for terminating VT paroxysms in adults and children are presented in Appendix A3, Tables A3.2 and A3.4.

• In patients with sustained monomorphic VT (SMVT) and hemodynamic instability, external electrical cardioversion (ECV) is recommended as first-line therapy [8, 67, 102, 106, 108, 127].

ESC IB (Level of Evidence C, Grade of Recommendation 5)

Comment. ECV is not indicated for patients with recurrent non-sustained VT.

In hemodynamically stable patients, recording a 12-lead ECG during any wide-complex tachycardia is of critical importance.

• During emergency medical care, paroxysms of wide-complex tachycardia should be recommended to be managed as VT unless the diagnosis of supraventricular tachycardia (SVT) is unquestionable [8, 127, 128, 129, 130, 131].

ESC IC (LoE C, SoR 5)

Comment. Interpreting a wide-complex tachycardia as SVT solely based on the absence of acute hemodynamic instability is a common clinical error. Drugs used to terminate VT are also effective for SVT, whereas drugs used to terminate SVT (#verapamil**) can cause blood pressure reduction and lead to acute hemodynamic instability in patients with VT.

• In patients with regular wide-complex tachycardia without hemodynamic instability and suspected SVT, vagal maneuvers are recommended [131, 132, 133, 134].

ESC IIaC (LoE C, GoR 5)

• If vagal maneuvers are ineffective in adult patients with regular wide-complex tachycardia without hemodynamic instability and suspected SVT, IV administration of #triphasadenine is recommended [108, 135, 136].

ESC IIaC (LoE C, GoR 3)

Comments. Certain types of VT, the mechanism of which is related to cAMP-mediated triggered activity, can be terminated by IV administration of #triphasadenine [136]. Drug doses for adults are specified in Appendix A3, Table A3.2

Atrial fibrillation in the presence of an accessory pathway can be diagnosed by the ECG pattern «FAST» («fast, wide, irregular»). It can mimic VT; therefore, IV administration of drugs that slow AV conduction (#triphasadenine, beta-blockers, verapamil**, digoxin**, and amiodarone**) should be avoided [137].

Immediate termination of SMVT is recommended even in the presence of hemodynamic stability, as the patient may experience rapid deterioration. VT termination can be achieved using ECV, antiarrhythmic drugs (AADs), or electrical pacing. All AADs can cause hypotension. In addition, the individual risk of anesthesia/sedation during ECV should be considered.

• In patients with SMVT without hemodynamic instability, ECV is recommended as initial treatment provided the risk of anesthesia/sedation is low [8].

ESC IC (RR S, ELD 5)

• In patients with SMVT and established or suspected arrhythmogenic right ventricular cardiomyopathy (ARVC) without hemodynamic instability, IV administration of #procainamide** is recommended [108, 138].

ESC IIaB (LoE B, GoR 2)

Comment. In the PROCAMIO trial [140], procainamide** administration was associated with a higher rate of VT termination and fewer serious adverse effects compared to amiodarone**. IV administration of #procainamide** should not be used in adult patients with severe heart failure, acute myocardial infarction, and end-stage renal disease. In patients with an ICD***, transvenous catheter overdrive pacing may lead to termination of VT with a cycle length shorter than that programmed in the ICD***.

Adult drug dosages are provided in Appendix A3, Table A3.2. Dosages of #procainamide** in children: 0.15–0.2 ml/kg [102, 108].

• In patients with SMVT without hemodynamic instability and without a confirmed diagnosis, it is recommended to consider IV administration of #amiodarone** [65, 67, 102, 108, 138].

ESC IIbB (LoE B, GoR 2 for adults; LoE C, GoR 5 for children)

Comment. Drug doses for children are specified in Appendix A3, Table A3.4.

• In patients with established idiopathic VT without hemodynamic instability, IV administration of a beta-blocker (for RVOT-VT) or #verapamil** or #triphasadenine (for fascicular VT, RVOT-VT) is recommended [67, 139, 140, 141, 142, 143, 144].

ESC I C (LoE C, GoR 4)

Comment. Drug doses for children are specified in Appendix A3, Table A3.4.

• IV administration of #verapamil** is not recommended for terminating wide-complex tachycardia of unknown etiology in adults [141, 142].

ESC IIIB (LoE C, GoE 4)

Comment. #Verapamil** is effective for terminating fascicular VT [140], but can cause severe hypotension.

A comprehensive evaluation of patients with sustained VT is mandatory if the underlying heart disease is unknown or its progression is highly likely. The physician's algorithm of actions regarding a patient with a first episode of SMVT is presented in Appendix B (Figure 3).

3.1.4 Management of patients with electrical storm and incessant ventricular tachycardia

Electrical storm is frequently encountered in patients with an ICD*** [116, 144, 145]. Patients who have experienced an electrical storm exhibit psychological disorders, HF decompensation, and an increased risk of death [146, 147]. The severity of an electrical storm can range from recurrent asymptomatic VT episodes terminating with #triphasadenine to life-threatening electrical instability with ventricular arrhythmia recurrences after frequent multiple shocks. Frequent ICD shocks may be inappropriate. Appendix B, Figures 2A, 2B, and 2C present the management algorithm for patients with electrical storm or repeated ICD shocks.

In patients with frequent unwarranted ICD*** discharges (e.g., due to SVT or intracardiac lead displacement, nonsustained VT, or persistently recurrent VT that terminates and restarts spontaneously), it is advisable to deactivate the ICD*** defibrillation function.

If an implantable antiarrhythmic device (IAD) programmer is unavailable, the ICD*** can be deactivated by placing a magnet over the device.

In the presence of hemodynamic instability, advanced CPR must be initiated [148]. Reversible conditions contributing to the initiation and maintenance of VT require correction (see section 3.1.1). Subsequent management depends on the type and etiology of VA [145, 148]. Treatment often requires a multimodal approach, including ICD*** reprogramming when necessary, antiarrhythmic drug (AAD) administration, sedation, cardioversion, autonomic nervous system modulation (neuromodulation), and mechanical circulatory support.

• Mild to moderate sedation is recommended for patients presenting with electrical storm to reduce psychological stress and lower proarrhythmic sympathetic tone [8].

ESC IC (LoE C, GoR 5)

• In patients with structural heart disease and electrical storm in the absence of contraindications, it is recommended to prescribe beta-blockers (preferably non-selective) combined with intravenous #amiodarone** [149, 150].

ESC IB (Level of Evidence C, Grade of Recommendation 5)

Comment. Non-selective beta-blockers, such as #propranolol**, which surpasses metoprolol** in efficacy [150], are most frequently used in combination with #amiodarone** [151]. Drug dosages are specified in Appendix A3, Tables A3.2 and A3.4.

The use of drugs such as #procainamide** [148] or lidocaine** [149, 152, 153] depends on the specific clinical scenario, type, and etiology of VA.

• Deep sedation with intubation is recommended for adult patients with drug-refractory electrical storm [154].

ESC IIaC (LoE C, GoR 4)

Comment. Confirmation in pediatric populations is lacking.

• Intravenous administration of #magnesium sulfate** with the addition of #potassium chloride** is recommended for patients with torsade de pointes VT [106, 107, 108, 117].

ESC IB (Level of Evidence C, Grade of Recommendation 5)

Comment. Drug dosages are specified in Appendix A3, Tables A3.2 and A3.4.

• Transvenous temporary ventricular overdrive pacing is recommended for adult patients with acquired LQTS and recurrent torsade de pointes VT, alongside the correction of underlying pathology and intravenous administration of #magnesium sulfate** [102, 105, 106, 107, 124].

ESC IC (RR S, ELD 5)

Comment. Drug dosages are specified in Appendix A3, Tables A3.2 and A3.4.

• Cardioversion is recommended for patients older than 16 years with incessant VT or electrical storm refractory to antiarrhythmic drugs [155, 156].

ESC IB (CGR B, LOR 3)

• Catheter ablation is recommended for adult patients with recurrent VT/VF episodes triggered by premature ventricular complexes with matching QRS morphology, refractory to medical therapy or unresponsive to coronary revascularization [157, 158, 159, 160].

ESC IIaC (LoE C, GoR 4)

Comment. The most common underlying arrhythmia driving electrical storm is Purkinje-related VT associated with structural heart disease, which is readily treatable by catheter ablation [146]. Retrospective analysis has demonstrated that successful ablation is associated with a significant reduction in VT recurrence, electrical storm frequency, and improved long-term survival [155]. In patients with incessant slow monomorphic VT, catheter ablation is preferred over antiarrhythmic drug therapy, which may paradoxically slow the VT further.

If beta-blocker therapy is insufficient or poorly tolerated for reducing sympathetic tone, certain patients may benefit from autonomic modulation, such as percutaneous stellate ganglion blockade [161], thoracic epidural anesthesia [162], or left cardiac sympathetic denervation [163].

• In adult patients with electrical storm refractory to medical therapy and where catheter ablation is ineffective or unfeasible, it is recommended to consider interventions targeting autonomic regulation (neuromodulation) [157, 162, 163].

ESC IIbC (LoE C, GoR 4)

• In cases of electrical storm refractory to AAD therapy and complicated by cardiogenic shock, it is recommended to consider mechanical circulatory support in patients older than 18 years [164, 165].

ESC IIbC (LoE C, GoR 4)

Comments. Mechanical circulatory support may be utilized to stabilize hemodynamics when conventional therapy fails, and to provide circulatory support during catheter ablation procedures [165]. A recently published meta-analysis [166] comprising 2,465 patients demonstrated a significantly lower mortality rate with prophylactic use of mechanical circulatory support among patients suffering from electrical storm or at high risk [167]. Conversely, emergent deployment of mechanical circulatory support during the ablation procedure was associated with a high mortality rate [168].

In patients with electrical storm triggered by recurrent paroxysmal VT or VF, subsequent management strategies are guided by the underlying cause of the ventricular arrhythmia.

3.2 General Principles of Treatment Aimed at Preventing Ventricular Arrhythmia Episodes

3.2.1 Medical therapy

An essential prerequisite for the successful management of VA and the prevention of SCD is the effective treatment of the underlying heart disease and comorbidities. Coronary artery disease is the principal cardiac pathology driving malignant ventricular tachyarrhythmias and SCD. Management of the underlying condition responsible for malignant ventricular tachyarrhythmias and SCD must be carried out in accordance with current clinical practice guidelines for the respective diseases/conditions.

Optimal medical therapy for the underlying heart disease, including maximally tolerated dosages of heart failure medications, is mandatory [169].

• In patients with heart failure with reduced ejection fraction, the use of ACE inhibitors/ARBs/ARNI, mineralocorticoid receptor antagonists (ATC C03DA Aldosterone antagonists), beta-blockers, and SGLT2 inhibitors is recommended to reduce heart failure mortality and SCD [170, 171, 172, 173, 174, 175, 176, 177, 178, 179, 180, 181, 182].

ESC IA (LoE C, GoR 5)

Antiarrhythmic drugs play an important role as adjunctive therapy in the management of VAs, particularly in symptomatic patients. To date, no antiarrhythmic agent other than beta-blockers has demonstrated a reduction in all-cause mortality. Each drug carries a significant potential for adverse effects, including proarrhythmia. For instance, numerous drugs prescribed for other indications can prolong the QT interval (http://www.crediblemeds.org) and provoke torsade de pointes VT. Certain agents possess negative inotropic and chronotropic properties, exacerbating heart failure and inducing bradycardia. Class IA and IC antiarrhythmic drugs, along with certain other sodium channel blockers, elevate the risk of VA in patients with Brugada syndrome (http://www.brugadadrugs.org).

The selection of a therapeutic strategy for VA is based on the presence or absence of structural heart disease and/or left ventricular dysfunction. A list of key antiarrhythmic drugs, indications for use, dosages, and adverse effects is provided in Appendix A3.

Medical Antiarrhythmic Therapy (AAT) for Ventricular Ectopic Activity in Patients Without Structural Heart Disease / Left Ventricular Dysfunction

• In patients without structural heart disease, pharmacological suppression of frequent premature ventricular complexes is recommended if the arrhythmia is accompanied by clinical symptoms, or if the burden exceeds 10% of total heartbeats on Holter monitoring and leads to left ventricular remodeling and decreased myocardial contractility [183, 184, 185, 186, 187, 188, 189].

ESC IC (LoE C, SoR 5)

Comment. Before prescribing any antiarrhythmic medications, it is crucial to verify that premature ventricular complexes are not the result of reversible causes (see section 3.1.1.). In the absence of structural heart disease/left ventricular dysfunction, so-called "idiopathic" ventricular ectopic activity may present as isolated premature ventricular complexes, couplets, nonsustained VT, or similar manifestations of ventricular parasystole. Patients without structural heart disease/left ventricular dysfunction have a favorable prognosis regardless of the morphological type of ventricular ectopy, the total daily burden of premature ventricular complexes, or the coupling interval, and do not require SCD prophylaxis [183, 184]. For specific considerations regarding the prescription of antiarrhythmic drugs in pediatric patients within this clinical context, refer to section 3.5.

• To suppress frequent, symptomatic ventricular ectopic activity in patients without structural heart disease / LV dysfunction, it is recommended to prescribe beta-blockers, class I antiarrhythmic drugs (AADs) (according to the E.M. Vaughan Williams classification modified by B.N. Singh and D.C. Harrison) (ATC C01B Antiarrhythmics, class I and III), non-dihydropyridine calcium channel blockers with direct cardiac effects (ATC C08D Selective calcium channel blockers with direct cardiac effects) (#verapamil**), #sotalol** and #amiodarone** (see Appendix A3, Tables A3.1 and A3.2) [108, 183, 184, 185].

ESC IIaB (LoE B, LoR 3 – for adults, LoR C, LoR 5 – for children)

Comment. The most effective agents for suppressing PVCs are class IC antiarrhythmic drugs (propafenone**, diethylaminopropionylethoxycarbonylaminophenothiazine [203, 204, 206, 207], lappaconitine hydrobromide**, and flecainide in adults), as well as class III AADs (ATC C01B Antiarrhythmics, class I and III) (#sotalol** and #amiodarone**). In frequent, symptomatic monomorphic PVCs originating from the RVOT area or fascicular PVCs from the LV, catheter ablation is recommended as the first-line treatment [190, 191].

A list of drugs recommended for the treatment of ventricular arrhythmias in adults and children, indicating their standard therapeutic doses, is presented in Appendix A3, Tables A3.1 and A3.2.

• Given the high probability of developing serious extra-cardiac adverse effects with long-term use of #amiodarone**, this drug is not recommended as a first-line AAD in patients with "idiopathic" ventricular arrhythmias, and may only be considered in symptomatic arrhythmia or decreased LVEF, provided that other antiarrhythmic drugs are ineffective or not tolerated [192].

ESC IIIC (LoE C, LoR 5)

Comment. Doses for adults and children are specified in Appendix A3, Tables A3.1 and A3.3.

• In the presence of non-sustained ventricular tachycardia episodes in patients without structural heart disease / LV dysfunction, for the prevention of arrhythmia recurrence, it is recommended to prescribe beta-blockers, #verapamil**, as well as class I and III AADs [66, 185, 193, 194, 195, 196, 197, 198, 199, 200, 201, 202, 203, 204, 205].

ESC IIaB (Level of Evidence B, Grade of Recommendation 3)

Comment. From the perspective of SCD risk, in most cases, patients with idiopathic VT have a favorable prognosis for life; however, these arrhythmias can be accompanied by pronounced systemic hemodynamic disorders (syncope, pulmonary edema), and in the case of a persistently chronic course, they can lead to a progressive decrease in myocardial contractility and the development of tachycardiomyopathy. In the absence of effective AAT, these conditions can significantly impair patients' quality of life. The choice of drug for AAT aimed at preventing VT recurrence should be made taking into account individual triggering factors and ECG changes characteristic of different forms of VT. Beta-blockers are the drugs of choice for idiopathic VT triggered by physical exertion or emotional stress. Prophylactic administration of #verapamil** is advisable for the treatment of non-paroxysmal RVOT-VT and the prevention of paroxysms of fascicular left ventricular tachycardia. The most effective agents for preventing recurrences of paroxysmal monomorphic VT, including those not associated with RVOT/FLVT, in adults are class IC AAP and amiodarone**. #Sotalol**, due to its insufficient efficacy and the potential risk of proarrhythmia associated with potassium channel blockade (TdP), should not be prescribed as a first-line drug. It is necessary to consider the possibility of extracardiac side effects with amiodarone**; therefore, in patients with idiopathic VPBs, this drug should be prescribed only if other class Ic AAP are ineffective or cannot be used, and interventional treatment methods are unavailable.

For specific features of prescribing medicinal products for the treatment of heart rhythm disorders in children in this clinical situation, see section 3.5.

A list of medications for adults and children is provided in Appendix A3, Tables A3.1 and A3.3 [65, 186, 194, 205].

As an alternative to pharmacological antiarrhythmic drug therapy for any idiopathic monomorphic VT, catheter ablation of the arrhythmia source should be considered [184, 190].

Pharmacological antiarrhythmic drug therapy of ventricular ectopic activity in patients with structural heart disease / LV dysfunction

• In the presence of ventricular ectopic activity in patients with structural heart disease / LV dysfunction, the risk of SCD is increased, and antiarrhythmic therapy is recommended for its prevention [206, 207, 208, 209, 210, 211, 212, 213].

ESC IA (LoE C, SoR 5)

Comment. In patients with structural heart disease, the risk of SCD depends on the nature of ventricular ectopic activity and the severity of LV dysfunction. The presence of frequent PVCs (>10 PVCs per hour), multiple forms of ventricular ectopic activity (paired PVCs, non-sustained ventricular tachycardia), and/or reduced LV contractility (LVEF < 40% according to echocardiography) in patients with structural heart disease is associated with an increased risk of SCD [206, 207].

• For the management of patients with structural heart disease / LV dysfunction who have an increased risk of SCD and require primary or secondary prevention thereof, it is recommended to prescribe beta-blockers [211, 213, 214, 215, 216, 217].

ESC IA (LoE C, SoR 5)

Comment. Beta-blockers (preferably selective lipophilic ones) should be prescribed taking into account contraindications to their use and potential adverse effects [211, 214].

• Pharmacological antiarrhythmic drug therapy is recommended for adult patients with structural heart disease / LV dysfunction to suppress frequent symptomatic PVCs, or if the ventricular ectopic activity count is >10% of the total daily heartbeats according to Holter ECG and is associated with cardiac chamber dilation and decreased LV myocardial contractility [191, 218, 219, 220].

ESC IC (LoE B, LoR 2)

• In patients over 18 years of age with implanted medical devices, such as an implantable three-chamber (biventricular) pacemaker***, implantable three-chamber (biventricular) cardioverter-defibrillator*** (for cardiac resynchronization therapy; hereinafter — implantable CRT device), the use of pharmacological antiarrhythmic therapy is recommended to suppress frequent PVCs in cases where they lead to a decrease in the proportion of biventricular paced rhythm below the recommended level [221, 222, 223].

ESC IIaB (LoE C, GoR 4)

Comment. To achieve the best CRT effect, one should strive for the highest possible percentage of biventricular paced rhythm (97-100%). The presence of at least 93% biventricular paced complexes (according to data from implanted CRT devices or obtained via Holter ECG) is considered optimal for CRT [224].

In children, it is advisable to adhere to the same approach, despite the lack of a sufficient evidence base.

• As antiarrhythmic treatment for PVCs in adult patients with structural heart disease / LV dysfunction, it is recommended to prescribe beta-blockers, sotalol**, amiodarone**, or a combination of beta-blockers and amiodarone** [102, 219, 220, 225, 226].

ESC IА (LOCR B, LOE 2)

Comment. Beta-blockers must be considered as the backbone of VPB AAT. Sotalol** suppresses ventricular ectopic activity more effectively than beta-blockers; however, its use is not recommended in patients with LVEF < 40% according to echocardiography, as well as with signs of CHF or renal failure. Amiodarone**, as monotherapy and in combination with beta-blockers, is the most effective AAP for treating VPBs in patients with ARVC/LV dysfunction. At the same time, its use is associated with the highest risk of severe extracardiac side effects. Consequently, amiodarone** should be prescribed when beta-blockers/sotalol** are ineffective or contraindicated, and interventional treatment for VPBs is not feasible. A list of drugs recommended for the treatment of VPBs, indicating their standard therapeutic doses, is presented in Appendix A3, Tables A3.1 and A3.3 [219].

ESC IIIA (LoE C, LoR 5)

Comment. Antiarrhythmic drugs (AADs), classes IA and IC, must not be used to suppress PVCs in patients with coronary artery disease (CAD), including post-myocardial infarction survivors, as well as in patients with other forms of heart disease leading to decreased LV contractility (LVEF < 40% on echocardiography) and/or manifestations of chronic heart failure (CHF). The administration of class IA and IC AADs is also contraindicated in patients with severe LV myocardial hypertrophy. Selective calcium channel blockers with a direct effect on the heart (#verapamil** and #diltiazem) are of low efficacy in treating ventricular arrhythmias (VA) in patients with structural heart disease (SHD) and may worsen the prognosis of patients with LV dysfunction and heart failure.

• Assessment of the efficacy and safety of suppressing ventricular ectopic activity in patients with SHD/LV dysfunction is recommended under the guidance of repeat 24-hour Holter ECG monitoring performed during the administration of antiarrhythmic drugs at a therapeutic dose for a duration sufficient to achieve their antiarrhythmic effect [207, 231, 232].

ESC IIaC (LoE C, GoR 5)

Comment. Assessment of the antiarrhythmic effect of beta-blockers is advisable on days 3–5 of their administration, #sotalol** – on days 5–7, #amiodarone** – taking into account pharmacokinetic features; the full therapeutic effect is assessed 4–6 weeks after the start of administration. The administration of each subsequent antiarrhythmic drug should be carried out no earlier than after 5 half-life periods of the previous one, and for #amiodarone** – no earlier than 1.5 months after its discontinuation. To assess the efficacy of the tested antiarrhythmic drugs, it is recommended to use the following criteria: when taking antiarrhythmic drugs at a therapeutic dose, a decrease in the total number of PVCs by more than 50% and/or a reduction in the number of hours per day during which PVCs were registered by more than 2 times compared to baseline without AAT is recorded. Concurrently, patients should exhibit a 10-fold or greater reduction in couplets of PVCs, as well as complete elimination of non-sustained ventricular tachycardia (NSVT). To assess the long-term efficacy and safety of antiarrhythmic drug therapy, regular ECG recording and the use of other diagnostic methods depending on the individual characteristics of patients are advisable [207].

• Administration of #amiodarone** or a combination of #amiodarone** with beta-blockers (excluding #sotalol**) is recommended for the prevention of paroxysmal VT/VF in patients with SHD or LV dysfunction as an alternative to an ICD*** if ICD implantation cannot be performed for any reason, or if patients refuse ICD*** implantation [213, 233, 234].

ESC IA (LoE C, GoR 5)

Comment. In patients requiring primary and secondary prevention of sudden cardiac death (SCD), #amiodarone** or its combination with beta-blockers is the only pharmacological alternative to an ICD*** capable of preventing the onset of VT/VF and increasing patient life expectancy. Catheter ablation of the arrhythmia source should be considered as an alternative to pharmacological AAT for recurrent episodes of VT/VF. In children, it is advisable to adhere to the same approach despite the lack of a sufficient evidence base. A list of drugs recommended for the treatment of VA, indicating their standard therapeutic doses, is presented in Appendix A3, Tables A3.1 and A3.3.

• Administration of prophylactic AAT with #amiodarone** is recommended for patients with SHD or LV dysfunction in the presence of recurrent episodes of VT/VF requiring ICD*** interventions despite beta-blocker therapy [65, 213, 233, 234].

ESC IIaC (LoE C, GoR 5)

Comment. The "first-choice" drugs for preventing recurrent episodes of VT/VF in patients with SHD or LV dysfunction are #sotalol**, #amiodarone**, and the combination of #amiodarone** with beta-blockers. Class IB AAD, #phenytoin**, is recommended as a "second-line" agent for frequent relapses of VT/VF in patients over 18 years of age with SHD and implanted ICDs***, in case of insufficient efficacy of beta-blockers, #sotalol**, and #amiodarone**, as well as when their administration is impossible due to absolute contraindications or severe adverse effects of treatment. #Phenytoin** is recommended for long-term oral administration in patients over 18 years of age at doses of 400–600 mg/day. The combined use of class IB AAD, #phenytoin**, and class III AAD (#sotalol** and #amiodarone**) is recommended for adult patients with SHD/LV dysfunction and an implanted ICD*** in cases where other treatment options (monotherapy and/or catheter ablation) have failed to eliminate recurrences of VT and VF. Catheter ablation of the arrhythmia source should be considered as an alternative to pharmacological AAT in case of recurrent episodes of VT/VF and appropriate ICD*** interventions. A list of medications for adult patients and children is presented in Appendix A3, Tables A3.1 and A3.3 [65, 148, 202, 231, 232, 233, 234, 235, 236, 237, 238].

• Treatment of patients with paroxysms of VT/VF is recommended to be carried out concurrently with the identification and elimination of individual pathogenetic factors underlying the onset of arrhythmia [142, 188, 239, 240].

ESC IC (LoE C, SoR 5)

Comment. Potential pathogenetic factors triggering the onset of VT include the arrhythmogenic effect of medications, electrolyte disturbances (hypokalemia, hypomagnesemia), elevated sympathetic nervous system tone, hyperthyroidism, hypovolemia, inflammation, myocardial volume and pressure overload, obstructive sleep apnea syndrome, hypoxia, and acute myocardial ischemia. Patients with heart failure and reduced LVEF must be on optimal medical therapy including ACE inhibitors/ARBs/ARNI, beta-blockers, aldosterone antagonists, and SGLT2 inhibitors [171, 172].

3.2.2 Antiarrhythmic devices

Implantable cardioverter-defibrillator***

An implantable cardioverter-defibrillator*** (ICD***) is a device designed to terminate life-threatening arrhythmias in order to prevent SCD [51].

ICD*** implantation is usually performed under local anesthesia. The use of ICD*** in the prevention of SCD is based on the arrhythmic mechanism of SCD development. Restoration of sinus (or underlying) rhythm occurs by delivering an electrical shock of several tens of joules or bursts of electrical pacing, which are painless for the patient and require less energy. The ICD*** should be considered as the primary modality for primary and secondary prevention of SCD [227, 245].

ICD for secondary prevention of SCD

• ICD*** implantation is recommended for patients with documented VF or VT with marked hemodynamic alterations, provided there are no transient causes for their development and at least 48 hours have elapsed since the onset of myocardial infarction. Patients must be receiving optimal medical therapy (OMT) and have a life expectancy of at least one year in a satisfactory clinical status [8, 51, 246].

ESC IA (LoE C, SoR 5)

ESC IIbC (LoE B, LoD 2)

• ICD*** implantation is recommended for patients over 18 years of age with sustained VT in the presence of moderately severe left ventricular dysfunction (LVEF less than 45%), regardless of the feasibility of catheter ablation and the results of the procedure [223, 224, 225].

RSCC IIaC (LoE B, LoD 2)

Comment. ICD*** implantation in patients with sustained VT is associated with increased survival compared to AAT. To date, there are no studies comparing the results of ICD*** therapy and catheter ablation without an ICD*** in patients with sustained VT. Considering the limited data and the high recurrence rate of sustained VT after catheter ablation, ICD implantation is advisable for all patients with LV dysfunction (LVEF < 45%) and sustained VT.

• ICD*** implantation is recommended for patients over 18 years of age with NSVT and LV dysfunction (LVEF less than 40%) due to a prior myocardial infarction and inducible sustained VT or VF during an electrophysiological study (EPS) [223, 224, 225].

RSCC IIaC (LoE B, LoD 2)

ICD for primary prevention of SCD

Randomized trials and meta-analyses have demonstrated that the risk of SCD is associated with impaired LV function, and the use of an ICD*** as a primary prevention tool for SCD significantly impacts the mortality rate in this category of patients with both ischemic and non-ischemic etiologies [225, 247, 248, 249, 250, 251, 252, 253, 254, 255, 256, 257].

For all indications for ICD*** use, the decision in favor of the latter is made only if the patient's predicted life expectancy exceeds 1 year. The need for adequate myocardial revascularization, along with the goal of radically eliminating arrhythmia, takes priority over ICD*** therapy.

Patients with heart failure with reduced LVEF must be on OMT, including ACE inhibitors/ARBs/ARNI, beta-blockers, aldosterone antagonists, SGLT2 inhibitors, with a reassessment of LVEF on therapy before deciding on ICD*** implantation for primary prevention of SCD, provided the predicted life expectancy is > 1 year.

• ICD*** implantation for primary prevention of SCD is not recommended within 40 days after myocardial infarction [247, 248].

ESC IIIA (LoE B, GoR 2)

• ICD implantation*** is recommended to reduce the risk of SCD in patients with LV dysfunction (LV EF 35% or less) and CHF (NYHA class II or III) NYHA receiving OMT, at least 40 days after MI and 90 days after myocardial revascularization [225, 247].

ESC IА (LOCR B, LOE 2)

• ICD*** implantation is recommended in patients with non-ischemic LV dysfunction (LVEF of 35% or less) and chronic heart failure NYHA class II or III on OMT [5, 111, 225, 254, 255, 256, 257, 258].

ESC IB (Level of Evidence C, Grade of Recommendation 5)

• ICD*** implantation is recommended for the prevention of SCD in patients older than 18 years awaiting heart transplantation outside a hospital setting [236, 237, 259, 260].

ESC IIaC (LoE B, GoR 3)

Comment. In children, it is advisable to follow the same approach despite the lack of a sufficient evidence base.

Conditions in which ICD therapy is not indicated or is contraindicated:

- the predicted life expectancy of patients with a satisfactory functional status does not exceed 1 year, even if they have indications corresponding to levels of evidence 1–5;

- patients suffering from incessantly recurrent VT or VF;

- patients with severe psychiatric disorders that may be exacerbated by device implantation or interfere with systematic follow-up;

- patients with NYHA class IV heart failure refractory to medical therapy who are not candidates for heart transplantation;

- patients with syncope of unclear origin without inducible ventricular tachyarrhythmias and without programmed ventricular stimulation;

- in cases where VT or VF are radically curable, either surgically or via catheter ablation;

- arrhythmias associated with WPW syndrome, ventricular outflow tract tachycardias, fascicular and idiopathic VT, in the absence of programmed ventricular stimulation;

- patients in whom a ventricular tachyarrhythmia episode occurred due to transient or reversible disorders (e.g., acute myocardial infarction, electrolyte imbalance, drug side effects, trauma), when correction of the disorder is possible and can significantly reduce the risk of arrhythmia recurrence.

Cardiac resynchronization therapy in patients with chronic heart failure to reduce the risk of SCD. Combined CRT-D devices (Three-chamber [biventricular] implantable cardioverter-defibrillator***)

The efficacy of CRT has been demonstrated in numerous clinical trials and meta-analyses in both ischemic and non-ischemic cardiomyopathy [261, 262, 263, 264, 265]. European registry data indicate lower mortality in patients with combined CRT-D devices (with defibrillator function) (Three-chamber [biventricular] implantable cardioverter-defibrillator***) [266].

• CRT device implantation (three-chamber [biventricular] implantable pacemaker*** or three-chamber [biventricular] implantable cardioverter-defibrillator***) is recommended in symptomatic patients older than 18 years with chronic heart failure, sinus rhythm, and left bundle branch block (LBBB) QRS morphology, QRS duration ≥ 150 ms, LVEF ≤ 35%, on OMT, to reduce symptoms, morbidity, and the risk of death [261, 267, 268, 269, 270, 271].

ESC IA (LoE B, GoR 2)

• CRT device implantation (three-chamber [biventricular] implantable pacemaker*** or three-chamber [biventricular] implantable cardioverter-defibrillator***) is recommended in symptomatic patients older than 18 years with chronic heart failure, sinus rhythm, and LBBB QRS morphology, QRS duration of 130–149 ms, LVEF ≤ 35%, on OMT, to reduce symptoms, morbidity, and the risk of death [268, 269, 270, 271].

ESC IB (Level of Evidence B, Grade of Recommendation 2)

• CRT device implantation (three-chamber [biventricular] implantable pacemaker*** or three-chamber [biventricular] implantable cardioverter-defibrillator***) is recommended in symptomatic patients older than 18 years with chronic heart failure, sinus rhythm, and non-LBBB QRS morphology, QRS duration ≥ 150 ms, LVEF ≤ 35%, on OMT, to reduce symptoms, morbidity, and the risk of death [269, 270, 271].

ESC IIaB (LoE B, GoR 2)

• CRT device implantation (three-chamber [biventricular] implantable pacemaker*** or three-chamber [biventricular] implantable cardioverter-defibrillator***) is recommended in symptomatic patients older than 18 years with chronic heart failure, sinus rhythm, and non-LBBB QRS morphology, QRS duration of 130–149 ms, LVEF ≤ 35%, on OMT, to reduce symptoms, morbidity, and the risk of death [269, 270, 271].

ESC IIbB (Level of Evidence B, Grade of Recommendation 2)

• CRT device implantation (three-chamber [biventricular] implantable pacemaker*** or three-chamber [biventricular] implantable cardioverter-defibrillator***) is not recommended in patients with chronic heart failure and a QRS duration of less than 130 ms [272, 273].

ESC IIIA (LoE B, GoR 2)

• CRT device implantation (three-chamber [biventricular] implantable pacemaker*** or three-chamber [biventricular] implantable cardioverter-defibrillator***) is recommended in patients older than 18 years with chronic heart failure, NYHA class III–IV, QRS duration ≥ 130 ms, LVEF ≤ 35%, with atrial fibrillation on OMT, to reduce symptoms, morbidity, and the risk of death. Patients must be provided with continuous biventricular pacing with effective ventricular capture [274, 275, 276, 277, 278].

ESC IIaB (LE B, LoE 2)

• In patients older than 18 years with a CRT device (three-chamber [biventricular] implantable pacemaker*** or three-chamber [biventricular] implantable cardioverter-defibrillator***) and atrial fibrillation, in case of ineffective biventricular pacing, it is recommended to induce heart block using catheter ablation of the AV node [279, 280].

ESC IIaC (LoE C, GoR 4)

• CRT device implantation (three-chamber [biventricular] implantable pacemaker*** or three-chamber [biventricular] implantable cardioverter-defibrillator***) is recommended in patients older than 18 years with atrial fibrillation, uncontrolled ventricular rate, who are candidates for AV node ablation [21, 281, 282, 283, 284].

ESC IIaB (LoE B, GoR 2)

• CRT device implantation (three-chamber [biventricular] implantable pacemaker*** or three-chamber [biventricular] implantable cardioverter-defibrillator***) is recommended in symptomatic patients older than 18 years with chronic heart failure, LVEF < 40%, who have indications for permanent ventricular pacing due to bradycardia, to reduce symptoms and morbidity [285, 286, 287, 288].

ESC IА (LOCR B, LOE 2)

• CRT device implantation (three-chamber [biventricular] implantable pacemaker*** or three-chamber [biventricular] implantable cardioverter-defibrillator***) is recommended as a replacement for an existing pacemaker*** or ICD*** for adult patients with LVEF < 40% who require permanent ventricular pacing, with progressive deterioration due to worsening chronic heart failure despite OMT [259, 288, 289, 290, 291, 292].

ESC IА (LOCR B, LOE 2)

Comment. The decision on selecting the type of resynchronization therapy device (three-chamber [biventricular] implantable pacemaker*** or three-chamber [biventricular] implantable cardioverter-defibrillator***) should be based on existing indications for ICD*** therapy and a detailed discussion of this issue with the patient and their relatives, taking into account the benefits of implanting a CRT device with defibrillation function and potential complications, consequences related to lifestyle changes, situations requiring device deactivation, and the feasibility of long-term patient follow-up.

Implantable cardioverter-defibrillator*** (subcutaneous)

Difficulties with the use of endocardial leads (defibrillator leads) in certain patients have led to the development of subcutaneous ICDs*** with one or two leads implanted subcutaneously, outside the thoracic cavity. Research results indicate that subcutaneous defibrillators can prevent SCD. Subcutaneous ICDs*** can be used for the primary prevention of SCD; however, to date, there are no long-term large-scale studies of such patient cohorts, and the corresponding effects of subcutaneous ICDs** have not yet been fully described. Prospective randomized trials are currently ongoing to compare efficacy and complications in patients with subcutaneous versus standard ICDs***.

• Implantation of a cardioverter-defibrillator*** (subcutaneous) is recommended as an alternative to a cardioverter-defibrillator with endocardial leads (Endocardial defibrillator lead***) in patients with indications for an ICD when antibradycardia pacing, CRT, and antitachycardia pacing are not required [293, 294, 295, 296, 297, 298].

ESC IIa C (LoE C, GoR 4)

• Implantation of a cardioverter-defibrillator*** (subcutaneous) is recommended as an alternative to a defibrillator with endocardial leads (Endocardial defibrillator lead***) in cases of complicated venous access, infectious complications related to a previous device, and in all instances where the use of endocardial leads is impossible, impractical, or potentially hazardous [293, 294, 295, 296, 297, 298].

ESC IIb C (LoE C, GoR 4)

Management of patients with an implanted cardioverter-defibrillator***

It is worth noting that the methodology for ICD*** programming in adults and children has no fundamental differences. There are no separate publications concerning the specific features of ICD*** programming in children.

• Discussion of potential lifestyle changes related to ICD*** implantation is recommended for all patients indicated for ICD*** therapy [299, 300, 301, 302].

ESC IC (LoE B, GoR 3)

• Assessment of mental status and treatment of psychiatric disorders are recommended for all patients with frequent ICD*** discharges [300, 301, 302].

ESC IC (LoE B, GoR 3)

• The need for ICD*** deactivation should be collectively discussed in the event of significant clinical deterioration and at the terminal stage of the disease, involving the patient or their legal representatives [303, 304].

RSC IC (LoE C, GoR 5)

Comment: when making a decision on ICD*** implantation, paramount importance is given to considering the patient's life expectancy, quality of life, and comorbidities, as well as evaluating and discussing these issues with the patient during ICD*** replacement.

Selected aspects of device-based therapy

Optimization of ICD*** programming.

ESC IA (LOCE B, LOE 1)

RSC IC (CGR C, LOR 5)

ESC IA (LoE C, GoR 5)

ESC IA (LoE C, GoR 5)

ESC IA (LoE B, GoR 2)

ESC IA (LoE B, GoR 2)

ESC IB (LoE B, GoR 3)

ESC IB (LoE C, GoR 4)

ESC IB (LoE B, GoR 2)

ESC IB (Level of Evidence C, Grade of Recommendation 5)

• In adult patients with subcutaneous implantable cardioverter-defibrillators***, it is recommended to program a dual detection zone with activation of the discrimination algorithm in the lower zone [323, 324, 325].

ESC IB (LoE B, GoR 3)

• For routine ICD*** programming, it is recommended to activate more than one tachycardia detection zone [316, 326].

ESC IIA (LoE C, GoR 4)

• Reprogramming of a previously implanted ICD*** is recommended in case of repeated inappropriate device activations [5, 51, 309].

RSC IC (LoE C, GoR 5)

Aspects of end-of-life patient management

At the end of a patient's life, palliative medical care becomes the primary approach in treatment, and the previously adopted treatment strategy may be modified. Palliative medical care is a set of measures including medical interventions, psychological support, and nursing care aimed at improving the quality of life of incurably ill citizens and directed at relieving pain and other severe disease manifestations [328]. Currently, discussions about individual treatment goals are rarely conducted with patients, even during the terminal stage of the disease [329]. Initiating palliative care for patients does not mean abandoning standard treatment approaches or a lack of chances for stabilization and/or improvement of their condition. Palliative care is provided to improve the quality of life (QoL) of the patient and their family members and continues alongside standard therapy for the patient's disease [330].

According to published data, in the last 30 days of life, 21% to 27% of patients with implanted defibrillator leads experienced therapeutic shocks [331, 332], which was accompanied by a sense of suffering [332]. An analysis of 130 ICD devices retrieved after patient death revealed that 31% of patients experienced a shock in the last 24 hours of life: 55% of them received 3 shocks, and 32% received more than 10 shocks. Nearby medical personnel or family members noted stress and pain in the dying patients [333, 334].

Over the past 10 years, the deactivation of ICD** defibrillation in patients with terminal chronic illness has been incorporated into treatment guidelines for these diseases as part of the palliative care strategy [169, 335, 336].

RSC IC (LoE C, GoR 5)

To disable the defibrillation function, all of the following criteria must be met:

- determination of the terminal stage of the disease or severe disease severity—unmodifiable by currently known methods of intervention—and determination of the palliative phase of treatment in conjunction with a specialist in the patient's primary disease;

- organ transplantation and/or implantation of mechanical circulatory support systems is not intended for the patient's treatment;

- the patient's own desire (if competent) to disable the defibrillation function (the patient's choice is focused on QoL and general comfort);

- informed consent to disable the ICD defibrillation function signed by the patient or their relatives (if the patient is incompetent or unconscious).

Comments. The decision to urgently disable the defibrillation function (to prevent continuous ICD*** firing) can be made and carried out (e.g., by placing a magnet over the ICD*** area) by a medical board at the time of death of a patient in the terminal stage of their disease. The decision to disable the defibrillation function is made by the patient and the medical board, with documentation in the inpatient or outpatient medical record and notification of the patient's relatives about this decision (with the patient's consent). Disabling the defibrillation function can be performed in outpatient, inpatient, or hospice settings. It is important to remember that the patient's decision to disable or enable the defibrillation function may change over time, and this decision should be considered decisive for implementation and documentation in medical records [338].

• Discussion of preliminary treatment planning, the purpose of which is for the physician or medical team to inform the patient and their family members about the course of the disease, treatment options, and palliative care, is recommended to be carried out before the patient finds it difficult to make their own decisions [330, 339].

ESC IB (Level of Evidence C, Grade of Recommendation 5)

Comments: treatment goals may change depending on the stage of the disease, the severity of comorbidities, and the patient's decision. Given the unpredictability of the disease course, the evolution of the patient's attitude towards treatment, and the possibility of a divergence between the patient's opinion and the opinion of family members regarding the disease and the scope of treatment, it is necessary to inform the patient and their relatives about the disease course, prognosis, and treatment options, and to jointly determine the goals and objectives of therapy [340].

3.2.3 Catheter ablation (radiofrequency ablation of arrhythmogenic zones; robotic-assisted radiofrequency ablation of arrhythmogenic zones; cryoablation of arrhythmogenic zones)

• Performing CA procedure for the treatment of VT/PVC is recommended using 3D navigation systems (cardiac mapping system with the ability to display 3D mapping results) to increase the safety and efficacy of the procedure [341].

RSC IIaC (LOC C, LOE 5)

Comments. In children, it is advisable to adhere to the same recommendation as in adults, despite the lack of a sufficient evidence base.

• In patients with recurrent NSVT or sustained polymorphic VT/VF, when ventricular arrhythmias are induced by repeated PVCs of identical morphology, it is recommended to consider the possibility of CA [51, 342].

RSC IIaC (LOC C, LOE 5)

Comments. In children, it is advisable to adhere to the same recommendation as in adults, despite the lack of a sufficient evidence base.

Catheter ablation (CA) (radiofrequency ablation of arrhythmogenic zones; cryoablation of arrhythmogenic zones) in patients without structural heart disease

The outflow tract region of the right and left ventricles is frequently the source of idiopathic VTs and PVCs. In 70% of cases, this is the right ventricular outflow tract (RVOT); in the remaining cases, the sinuses of Valsalva, the left ventricular outflow tract (LVOT), the great cardiac vein, epicardial zones, the aortomitral junction, and less commonly, the proximal pulmonary artery directly above the pulmonic valve. Idiopathic focal outflow tract VT (OT-VT) typically occurs in patients without structural heart disease, although minor changes on MRI have been identified in some patients.

Ventricular tachycardia originating from the cardiac outflow tract

• Performing CA of ventricular arrhythmias presumably originating from the RVOT area is recommended in the presence of symptoms and/or in case of inefficacy of AAT (e.g., beta-blockers), as well as in patients with impaired LV systolic function due to frequent VT/PVC [51, 116, 342, 343].

ESC IB (Level of Evidence C, Grade of Recommendation 5)

Comment. For patients with VT/PVC presumably originating from the RVOT, CA is recommended as a first-line treatment method, whereas for VT/PVC originating from the LVOT, its performance should be considered only in the absence of AAT efficacy.

• Performing CA by experienced specialists for the treatment of VT/PVC presumably originating from the LVOT, the aortic valve area, or epicardial VT/PVC is recommended in symptomatic patients when 1 or more class IC APDs are ineffective, and also when patients are unwilling to remain on long-term AAT [186, 344].

ESC IIaB (LoE C, GoE 5)

• Catheter ablation for the treatment of VT/PVC presumably originating from the sinuses of Valsalva is recommended only when class IC APD therapy is ineffective [344].

ESC IC (RR S, ELD 5)

• An epicardial approach for VT/PVC ablation is recommended only after failed endocardial ablation of outflow tract VT/PVC [345].

ESC I C (LoE C, GoR 4)

Comment. Most focal epicardial VTs arise in close proximity to major cardiac veins or coronary arteries, and the main risk of such a procedure is coronary artery injury.

More detailed information on performing CA in pediatric patients without structural heart disease can be found in section 3.5.

Idiopathic left ventricular tachycardia

Fascicular VT is the most common type, with the reentry circuit localized in the branching area of the posterior branch of the left bundle branch (> 90%), and rarely the anterior branch, developing predominantly in young individuals without structural heart disease. CA is the treatment method of first choice for such patients in experienced centers, because the disease occurs mainly in young persons, and long-term drug therapy is ineffective in this case.

Ventricular tachycardia originating from the papillary muscles, mitral or tricuspid annulus area

• In the absence of a response to treatment of VT/PVC originating from the papillary muscles, mitral or tricuspid annulus area with antiarrhythmic drugs, class IC and/or beta-blockers, CA is recommended [51, 346].

ESC IC (RR S, ELD 5)

Comment. When mapping and performing ablation in the papillary muscle area, it is quite difficult to achieve a stable catheter position, therefore transseptal access is recommended in some cases, along with monitoring using intracardiac echocardiography. Successful ablation can very rarely be complicated by mitral regurgitation.

Catheter ablation (CA) (radiofrequency ablation of arrhythmogenic zones; cryoablation of arrhythmogenic zones) in patients with structural heart disease / left ventricular dysfunction

In patients with LV dysfunction and sustained VT, the pathophysiological mechanism of the arrhythmia in many cases consists in the formation of a reentry circuit against the background of scar changes, and the target of ablation is the critical isthmus within this circuit. VT in such patients is most often monomorphic in character. The preferred procedural endpoint is the absence of any inducible VTs. In the event of electrical storm development, performing CA can help terminate it and reduce the frequency of recurrent episodes compared to medical therapy.

• Performing urgent CA in experienced centers is recommended in patients with incessant VT or electrical storm leading to repeated ICD shocks*** [51, 155, 156].

ESC IB (Level of Evidence C, Grade of Recommendation 5)

Comment. In children, it is advisable to adhere to the same recommendation as in adults, despite the lack of a sufficient evidence base.

• The administration of #amiodarone** or CA is recommended in patients with recurrent ICD*** shocks due to sustained VT [102, 108, 236].

ESC IB (Level of Evidence C, Grade of Recommendation 5)

Comment. Doses of amiodarone** for adult patients and #amiodarone** for children are presented in Appendix A3 (Tables A3.1-A3.4)

• Performing CA is recommended after the registration of the first episode of sustained VT in certain patients over 18 years of age with an ICD*** to reduce the risk of subsequent device firings [237, 238, 240].

RSC IIaB (LoE B, GoE 2)

Comment. To make such a decision, a joint discussion between the cardiologist and the specialist performing catheter interventions is required. Performing CA is advisable at a medical institution with experience in such procedures (an experienced center). If CA cannot be performed in such patients, it is advisable to prescribe amiodarone**. Amiodarone** doses for adult patients are presented in Appendix A3 (Table A3.1).

• In patients with LV dysfunction referred for VA catheter ablation, pre-procedural or intra-procedural imaging is recommended to rule out intracardiac thrombosis [347, 348, 349].

ESC IB (LoE B, GoR 2)

• In adult patients with non-ischemic or ischemic cardiomyopathies referred for catheter ablation of VT, myocardial MRI imaging is recommended to increase the efficacy of the intervention and reduce the likelihood of VT recurrence [350, 351].

ESC IIaB (LoE B, GoR 2)

• In patients over 18 years of age with scar-related VT, substrate ablation is recommended to increase the efficacy of the intervention and reduce the likelihood of VT recurrence [352, 353].

ESC IB (LoE B, GoR 2)

ESC IIaB (LoE C, GoE 5)

Ventricular extrasystoles in patients with structural heart disease / left ventricular dysfunction

• In patients with SHD/LV dysfunction with frequent symptomatic PVCs or recurrent NSVT, performing CA is recommended [51, 342, 357, 358].

ESC IIaB (LoE C, GoE 5)

• In the presence of LV dysfunction associated with PVCs, performing CA is recommended [51, 342, 358].

ESC IIaB (LoE C, GoE 5)

3.2.4 Modulation of autonomic nervous activity (neuromodulation)

The role of the autonomic nervous system in the development of arrhythmias is well recognized [360]. It was previously demonstrated that sympathetic activation plays a key role in the induction of ventricular arrhythmias, particularly in certain inherited disorders such as congenital long QT syndrome (LQTS) and catecholaminergic polymorphic ventricular tachycardia (CPVT) [361, 362], whereas left-sided cardiac sympathetic denervation reduces the frequency of arrhythmic syncopes in congenital LQTS [363]. The efficacy of cardiac sympathetic blockade using various approaches (thoracic epidural anesthesia, percutaneous stellate ganglion block, or surgical resection of the stellate ganglion) in reducing arrhythmia severity in refractory VT/VF has been proven [161, 164]. Further studies are needed to identify the patient cohort that would benefit most from neuromodulation for the termination and prevention of VT/VF.

• In adult patients with VT/VF and ineffective therapy with beta-blockers and/or other antiarrhythmic drugs, when catheter ablation is ineffective, contraindicated, or impossible, cardiac sympathetic denervation is recommended to be considered [163].

RSC IIaB (LoE C, GoR 4)

3.3 Management of patients with specific nosologies

3.3.1 Idiopathic ventricular arrhythmias

Idiopathic ventricular arrhythmias are defined as those occurring without structural heart disease (SHD) and channelopathies [8].

• In individuals with asymptomatic ventricular extrasystoles (VE) without SHD and/or inherited channelopathy, when the burden of ectopic complexes exceeds 10% of the total heart beats according to 24-hour Holter ECG monitoring, or in the presence of nonsustained ventricular tachycardia (NSVT), dynamic follow-up is recommended for the potential detection of cardiovascular disease [51, 363, 364, 365, 366].

ESC IC (Level of Evidence C, Grade of Recommendation 5)

• In patients with VE/VT with QRS morphologies uncharacteristic of idiopathic arrhythmias, even with normal echocardiography results, cardiac MRI is recommended to diagnose structural pathology [66, 186].

ESC IIaC (LoE C, GoR 5)

ESC IIaB (LoE B, GoR 3)

• In patients without SHD/LV dysfunction, medical therapy for asymptomatic infrequent VE/NSVT is not recommended, as these patients have a low risk of sudden cardiac death (SCD) and do not require its prevention [207, 368, 369, 370].

RCS IIIC (LoE C, GoR 5)

Comment. From the perspective of SCD risk, patients without SHD have a favorable prognosis regardless of the type of ventricular ectopic activity and the total number of VE per 24 hours [183, 184, 186].

• Beta-blockers, class IC antiarrhythmic drugs, or direct-acting calcium channel blockers (#verapamil**) are recommended in patients with VE/VT originating from the ventricular outflow tract (VOT) and in idiopathic left ventricular (fascicular) tachycardia when symptoms are present and the patient refuses catheter ablation, or if ablation is impossible or associated with a high risk [51, 185, 371, 372].

ESC IIaC (LoE C, GoR 4)

Comment. A list of medications with dosages for adult patients and children is provided in Appendix A3, Tables A3.1 and A3.3).

Catheter ablation is the treatment of choice for VE/VT originating from the VOT and for idiopathic left ventricular (fascicular) tachycardia.

• In patients with idiopathic VE/VT with a location outside the VOT in the presence of symptoms, the use of beta-blockers or direct-acting calcium channel blockers (#verapamil**) is recommended [51, 102, 185, 343, 371].

ESC IC (LoE C, SoR 5)

Comment. A list of medications with dosages for adult patients and children is provided in Appendix A3, Tables A3.1, A3.2, A3.3, A3.4).

• Class IC antiarrhythmic drugs, in the presence of symptoms, are recommended in patients with idiopathic VE/VT with locations outside the VOT [343, 372, 373].

ESC IIaC (LoE C, SoE 4)

• Amiodarone** is not recommended as first-line therapy in patients with idiopathic VE/VT [8, 184].

ESC IIIC (CGR C, LOR 5)

Comment. The most effective agents for treating VE/NSVT in adults without SHD are class IC antiarrhythmic drugs (propafenone**, diethylaminopropionylethoxycarbonylaminophenothiazine, lappaconitine hydrobromide**, flecainide) [185, 192, 193, 197, 200, 201, 202, 203, 204, 372], as well as amiodarone**. The use of amiodarone** in this group of patients is limited by extracardiac side effects [192] and is advisable only in the presence of SHD, including cardiomyopathy associated with frequent VE (see below) [188, 190]. The list of drugs is presented in Appendix A3, Tables A3.1 and A3.3.

• In adult patients with cardiomyopathy associated with frequent monomorphic VE, antiarrhythmic drug therapy, including amiodarone**, is recommended if the patient refuses catheter ablation, or if ablation is impossible, associated with a high risk, or has been ineffective [189, 374, 375, 376].

ESC IIaC (LoE B, GoR 2)

The right and left ventricular outflow tract region is frequently a source of idiopathic VT and VE [343, 377]. In 70% of cases, this is the right ventricular outflow tract (RVOT), and in remaining cases—the sinuses of Valsalva, left ventricular outflow tract (LVOT), great cardiac vein, epicardial areas, aortomitral junction, and less commonly the proximal pulmonary artery directly above the pulmonary valve [344, 345, 376, 377].

Idiopathic VT from the outflow tract usually occurs in patients without SHD, although minor abnormalities have been detected on MRI in some patients. Idiopathic VT generally has a benign course, but malignant VT can occur in some cases [343, 375, 376, 378, 379].

• Catheter ablation is recommended for patients with symptomatic VE/VT from the VOT as first-line therapy [8, 51, 190, 382].

ESC IB (Level of Evidence C, Grade of Recommendation 5)

• Catheter ablation is recommended for patients with idiopathic symptomatic left ventricular (fascicular) tachycardia as first-line therapy [8, 191, 382].

ESC IB (Level of Evidence C, Grade of Recommendation 5)

• Catheter ablation is recommended in patients over 18 years of age with idiopathic symptomatic VE/VT with locations outside the VOT [51, 191, 382].

ESC IIaC (LoE C, SoE 4)

Comment. Catheter ablation of VE/VT outside the VOT (LVOT, epicardial location, papillary muscles, mitral and tricuspid valve rings) is frequently associated with technical difficulties and a higher procedural risk; therefore, it is recommended as an alternative to class IC antiarrhythmic drugs when beta-blockers are ineffective.

• In asymptomatic patients over 18 years of age, to prevent LV systolic dysfunction due to VE-induced cardiomyopathy, it is recommended to consider performing catheter ablation of idiopathic VE when the ectopic complex burden is greater than 20% of the total daily heart beats according to Holter ECG monitoring [191, 218, 383].

ESC IIB (LoE B, GoR 3)

• Catheter ablation is recommended for patients with cardiomyopathy developing as a result of frequent monomorphic VE [51, 191, 218, 384, 385, 386].

ESC IC (LoE C, SoR 5)

3.3.2 Coronary artery disease

3.3.3 Acute coronary syndrome and acute myocardial infarction in adult patients

The incidence of ventricular arrhythmias in acute coronary syndrome (ACS) during the in-hospital stage has decreased due to early and active revascularization and timely adequate pharmacotherapy. Nevertheless, 4–12% of patients with ST-segment elevation myocardial infarction (STEMI) develop ventricular arrhythmias within the first 48 hours of symptom onset [387, 388, 389].

Pre-reperfusion ventricular arrhythmias are more common than reperfusion-induced or post-reperfusion arrhythmias in STEMI [390]. Hemodynamic instability, cardiogenic shock, left ventricular ejection fraction < 40%, and the sum of ST-segment deviations across all leads are independent predictors of ventricular arrhythmias in both STEMI and non-STEMI [387, 391]. In addition, early repolarization is associated with an increased risk of ventricular arrhythmias and SCD in ACS [392].

Prevention of ventricular arrhythmias in STEMI

Urgent reperfusion is the most important therapy [393, 394], as acute ischemia triggers arrhythmias. Beta-blocker therapy is also advisable to prevent ventricular arrhythmias [395, 396].

In cases of ACS and recurrent sustained and/or hemodynamically significant VT or VF, rapid and successful revascularization is crucial for preventing subsequent arrhythmias and must be performed without delay [397, 398, 399].

ESC IIbC (Level of Evidence C, Grade of Recommendation 5)

• Emergency reperfusion is recommended in STEMI to reduce ischemic myocardial injury and electrical instability [401, 402, 403].

ESC IA (LOCE B, LOE 1)

ESC IIbC (Level of Evidence C, Grade of Recommendation 5)

ESC IIbC (LoE B, GoR 1)

• Admission to an intensive care unit is recommended for out-of-hospital cardiac arrest survivors who are in a coma without ECG signs of STEMI after resuscitation [5, 51, 393, 406].

ESC IIaB (LoE C, GoE 5)

• Emergency CAG (< 2 h) is recommended for out-of-hospital cardiac arrest survivors presenting in a comatose state when non-coronary causes are ruled out, particularly in patients with hemodynamic instability [393, 406, 407].

ESC IIaB (LoE C, GoR 4)

Comment. Acute ischemia causes electrical instability and triggers ventricular arrhythmias in ACS [408]. Early administration of beta-blockers is recommended to reduce the likelihood of VT/VF in ACS [407, 409, 410]. In some cases, correction of hypomagnesemia and hypokalemia is helpful. HMG-CoA reductase inhibitors reduce mortality among patients with CAD, primarily by preventing recurrent coronary events, and are part of standard treatment for such patients [400, 401]. The occurrence of VF in the early period (i.e., within 48 hours) of ACS is associated with a fivefold increase in the risk of in-hospital mortality [411].

• Intravenous (i.v.) administration of beta-blockers is recommended for patients with recurrent VT/VF during STEMI in the absence of contraindications [407, 409].

ESC IB (Level of Evidence C, Grade of Recommendation 5)

• I.v. administration of amiodarone** is recommended for patients with recurrent VT/VF during the acute phase of ACS [128, 410, 411, 412].

ESC IIaC (LoE B, GoR 3)

ESC IIbC (Level of Evidence A, Grade of Recommendation 1)

• Prophylactic administration of antiarrhythmic drugs (other than beta-blockers) is not recommended for patients with ACS without documented episodes of VT/VF [216, 256, 389, 396, 418].

ESC IIIB (LoE C, LoD 4)

• ICD*** implantation is recommended in survivors of SCD due to coronary artery spasm [413, 414, 415].

ESC IIaC (LoE C, GoR 4)

SCD risk stratification in the acute phase (first 10 days) of MI

Most studies evaluating the utility of non-invasive risk stratification methods were conducted in patients with severely reduced LVEF (< 40%) or in mixed cohorts. Results for patients with LVEF > 40% were either not reported or the subgroups of such patients were too small to allow reliable analysis and data interpretation. Currently, there are no sufficiently specific and sensitive non-invasive risk stratification methods for post-MI patients with a normal LVEF.

Limited data from subgroups of large trials suggest that programmed ventricular stimulation (PVS) may be used for post-MI risk stratification in patients with LVEF > 40% [416, 417, 418]. This method is currently being evaluated in the ongoing PRESERVE-EF trial on risk stratification in patients with preserved LVEF.

• Non-invasive methods (e.g., T-wave alternans, autonomic dysfunction, or signal-averaged ECG) are not recommended for risk stratification in the early post-MI period [417, 418, 419].

ESC IIIB (CGR B, LOR 2)

• Early (pre-discharge) LVEF assessment is recommended for all patients after MI [5, 51, 78, 401, 420].

ESC IB (LoE B, GoR 3)

• Re-evaluation of reduced LVEF (< 35%) is recommended 6–12 weeks after MI to determine the need for ICD*** implantation for primary prevention of SCD [5, 51, 418, 419].

ESC IC (LoE B, LoR 2)

Comment. In special cases, such as incomplete revascularization, preexisting LVEF impairment, and arrhythmia onset later than 48 hours after ACS, early (< 40 days) ICD*** placement may be considered. The type of ventricular arrhythmia (monomorphic, polymorphic, pleomorphic VT, or VF) as well as VT cycle length (short non-sustained and long non-sustained cycles) should be taken into account. If programmed stimulation is performed, the induction and type of induced arrhythmia (monomorphic VT, polymorphic VT, VF) are additionally assessed [248].

• Coronary revascularization is recommended for patients with reduced LVEF and preceding signs of myocardial ischemia to reduce the risk of SCD [5, 51].

ESC IB (Level of Evidence C, Grade of Recommendation 5)

3.3.4 Chronic coronary artery disease in adult patients

Primary prevention of SCD in patients with reduced LVEF

At 40 days after STEMI, approximately 5% of patients have an LVEF of less than 35%, which increases the risk of SCD [418, 419, 420]. Primary prevention of SCD via ICD*** implantation is recommended for patients with an LVEF ≤ 35% and NYHA class II and III heart failure symptoms [225]. ICD*** implantation should also be considered in asymptomatic patients with an LVEF ≤ 30% [251]. In this patient group, mortality reduction with ICD*** has been demonstrated in four randomized clinical trials [225, 249, 250, 251]. ICD*** implantation is recommended for CAD patients with reduced LVEF (≤ 40%) and asymptomatic PVS-inducible VT, regardless of NYHA class [250].

Since the publication of the aforementioned studies, the use of early revascularization has expanded and new therapies for HF have been introduced, which has reduced the overall risk of SCD in patients with HF [421, 422].

• EPS is recommended in patients with syncope and a history of STEMI if syncope remains unexplained after non-invasive evaluation [421, 422].

ESC IB (LoE C, GoR 5)

• ICD*** implantation is recommended in patients with CAD, symptoms of chronic heart failure (NYHA class II–III) and LVEF ≤ 35% on optimal medical therapy lasting more than 3 months [225, 251].

ESC IA (LoE B, GoR 2)

• ICD*** implantation is recommended in patients with CAD, symptoms of chronic heart failure (NYHA functional class I) and LVEF ≤ 30% on optimal medical therapy lasting more than 3 months [251].

ESC IIaB (LOCE B, LOE 2)

• ICD*** implantation is recommended in patients with CAD, LVEF ≤ 40% on optimal medical therapy lasting more than 3 months, and sustained VT if it is inducible during EPS [250].

ESC IIaB (LOCE B, LOE 2)

• Prophylactic antiarrhythmic drug therapy, other than beta-blockers, is not recommended in patients with CAD without documented sustained VT/VF episodes [220, 221, 222].

ESC IIIA (CoE B, LOE 2)

Secondary prevention of SCD and treatment of ventricular arrhythmias

• ICD*** implantation is recommended in patients without ongoing ischemia who have confirmed VF or hemodynamically significant VT occurring more than 48 hours after MI [227, 250, 423, 424, 425].

ESC IA (LoE B, GoR 2)

• Catheter ablation is recommended in patients with CAD and recurrent symptomatic sustained VT and/or ICD*** shocks due to VT, despite ongoing amiodarone** therapy, instead of escalating antiarrhythmic drug therapy [155, 158, 160, 246, 347, 427].

ESC IB (LoE B, GoR 2)

• The addition of oral amiodarone** or replacement of beta-blockers with sotalol** is recommended in patients with CAD with recurrent symptomatic sustained VT and/or ICD*** shocks for the management of sustained VT during beta-blocker therapy [151, 425].

ESC IIaB (LOCE B, LOE 2)

• ICD*** implantation is recommended in patients with hemodynamically significant sustained VT and LVEF ≥ 40% if catheter ablation of VT is ineffective, unavailable, or undesirable [8].

ESC IIaC (LoE C, GoR 5)

• Catheter ablation is recommended in patients with CAD and recurrent symptomatic sustained VT or ICD*** shocks due to VT, despite treatment with beta-blockers or sotalol** [237].

ESC IIaC (LoE B, GoR 2)

ESC IIb B (LoE B, GoR 2)

• In patients with CAD and hemodynamically stable sustained VT and LVEF ≥ 40%, catheter ablation in experienced centers is recommended as an alternative to ICD*** provided that non-inducibility of VT is achieved and all late and fractionated ventricular myocardial electrograms are eliminated [425, 426, 427].

ESC IIaC (LoE B, GoR 2)

Left ventricular aneurysm. Ischemic cardiomyopathy. Chronic heart failure.

• The incidence and severity of ventricular arrhythmias increase with the progression of heart failure, although the prognostic significance of ventricular arrhythmias for SCD risk assessment remains unclear. Optimal medical therapy with ACE inhibitors (or ARBs in case of ACE inhibitor intolerance), beta-blockers, or aldosterone antagonists is recommended in patients with chronic heart failure and left ventricular systolic dysfunction (LVEF ≤ 35–40%) to reduce overall mortality and SCD risk [171, 428, 429, 430, 431].

Level of Certainty of Evidence B, Level of Reliability of Data 1

• Surgical left ventricular reconstruction during coronary artery bypass grafting is recommended in patients with NYHA class III–IV chronic heart failure, patients with a large left ventricular aneurysm, a large thrombus, a history of thromboembolic events, or in case of aneurysm-related arrhythmia [432, 433, 434, 435].

ESC IIaA (LoE B, GoR 2)

Comment. The goal of surgical left ventricular reconstruction is to remove scar tissue using endocardial resection and endoventricular plasty with normalization of left ventricular shape and volume to improve diastolic and concentric systolic functions, eliminate the reentry zone, resolve myocardial ischemia, and correct mitral annular dilatation [431, 432, 433, 435].

Surgical treatment of ventricular tachycardia

Surgical treatments for ventricular arrhythmias include endocardial ablation and resection. Surgical ablation can be performed endocardially and epicardially using high-frequency radiofrequency current (radiofrequency ablation of arrhythmogenic zones) or myocardial freezing (cryoablation of arrhythmogenic zones). The localization of ventricular arrhythmia zones should be identified using baseline EPS before surgery and refined during mapping during open-heart surgery.

• Surgical ablation in experienced centers with mandatory postoperative electrophysiological monitoring (induction) is recommended for patients with therapy-refractory VT, in case of an unsuccessful or impossible catheter ablation attempt for the suppression and prevention of VT/VF recurrence [5, 434, 435, 436].

ESC IB (LoE C, GoR 4)

• Endocardectomy during surgical LV reconstruction is recommended for patients with VT in the setting of post-infarction LV aneurysm for the management and prevention of VT/VF recurrence [434, 435, 436, 437, 438, 439].

ESC IIaA (Level of Evidence C, Quality of Evidence 4)

Comment. Endocardial resection can also be performed in patients with an LV aneurysm without documented VT, since the risk of developing VT in the presence of a post-infarction LV aneurysm is 50%.

• ICD implantation*** is recommended for patients after surgical LV reconstruction with inducible VT in the early postoperative period for the management of postoperative VT/VF episodes [433, 434, 439, 440].

ESC IIaB (Level of Evidence B, Grade of Recommendation 3)

Anomalous aortic origin of coronary arteries

Anomalous aortic origin of coronary arteries is associated with an increased risk of SCD, especially in individuals under 35 years of age during or after intense physical exercise [440]. Risk factors for SCD include the course of the coronary artery between the aorta and pulmonary artery, slit-like ostium, high take-off, acute-angle take-off of the coronary artery, intramural course of the coronary artery, and the length of the intramural segment [441].

Indications for surgical intervention, especially in asymptomatic patients, are the presence of a high-risk anatomical variant (visualized by CT angiography) and myocardial ischemia (exercise stress test) [441].

• Exercise stress echocardiography is recommended for patients over 18 years of age with an anomalous aortic origin of coronary arteries in addition to a cardiorespiratory exercise test to confirm/exclude myocardial ischemia [36, 67, 69, 442].

ESC IC (Level of Evidence C, Quality of Evidence 4)

• Exercise stress echocardiography is recommended for patients over 18 years of age with an anomalous aortic origin of coronary arteries and a history of cardiac arrest, following surgical treatment, in addition to a cardiorespiratory exercise test [36, 67, 69, 442].

ESC IC (Level of Evidence C, Quality of Evidence 4)

• Surgical correction of coronary artery anomaly is recommended for patients with an anomalous aortic origin of coronary arteries presenting with cardiac arrest, syncope presumably caused by ventricular arrhythmias, or angina pectoris when other causes have been excluded [440, 441, 442, 443, 444].

ESC IC (Level of Evidence C, Grade of Recommendation 4)

• Surgical correction of coronary artery anomaly is recommended in asymptomatic patients with an anomalous aortic origin of coronary arteries and evidence of myocardial ischemia, or anomalous origin of the left coronary artery with high-risk anatomy [440, 441, 442, 443].

ESC IIaC (LoE B, GoR 3)

3.3.5 Dilated cardiomyopathy

Dilated cardiomyopathy (DCM) is characterized by LV dilatation and systolic dysfunction unrelated to CAD and/or hemodynamic overload [444]. The causes of DCM can be genetic or acquired. An interaction between genetic predisposition and external factors such as alcohol, chemotherapy, and the peripartum period is also possible. The phenotype of DCM, particularly in genetic etiology, may change over time and may not meet standard disease criteria at the time of manifestation and diagnosis.

The main causes of cardiovascular mortality in DCM are progressive HF and SCD due to ventricular arrhythmias or, less commonly, bradyarrhythmias. It has been shown that 5-year mortality in DCM patients with HF on guideline-directed medical therapy is 21-28%. SCD occurs in 12% of patients with DCM and accounts for 25-35% of all deaths [225].

Risk stratification and management of patients with DCM

• Genetic testing with mutation analysis of at least LMNA, PLN, RBM20, FLNC genes is recommended for patients with DCM/LVNC under 50 years of age with slowed AV conduction or a family history of DCM or SCD in first-degree relatives under 50 years of age [111, 445, 446, 450].

ESC IB Level of Evidence C, Quality of Evidence 4

Comment. The LMNA gene encodes nuclear lamin proteins; the PLN gene encodes phospholamban; the RBM20 gene encodes the RBM20 protein, which is a splicing activator; the FLNC gene encodes filamin C. Mutations in these genes are associated with a high risk of ventricular arrhythmias and SCD, regardless of the degree of LVEF reduction.

• Genetic testing with mutation analysis of at least LMNA, PLN, RBM20, FLNC genes is recommended for risk stratification in sporadic DCM in young patients or those with disease features characteristic of a hereditary etiology [111, 445, 446, 447, 448, 449, 450].

ESC IIaC (LoE B, GoR 2)

• Patients with non-ischemic cardiomyopathy are recommended to undergo contrast-enhanced cardiac MRI (ATC V08CA Paramagnetic contrast media) to potentially determine the etiology of the disease and the risk of ventricular arrhythmias and SCD [451, 452, 453].

ESC IIaB (Level of Evidence C, Quality of Evidence 5)

Comment. Late gadolinium enhancement (ATC V08CA Paramagnetic contrast media) in the myocardium on MRI is associated with a high risk of ventricular arrhythmias and SCD, including when LVEF is greater than 35%.

• Adult patients with DCM and syncopal episodes are recommended to undergo baseline EPS if the cause of syncope remains unclear after evaluation using non-invasive diagnostic methods [453, 454, 455].

ESC IIaC (LoE B, GoR 2)

Primary prevention of SCD in patients with DCM

• Patients over 18 years of age with DCM are recommended optimal medical therapy (OMT) (ACE inhibitors, beta-blockers, aldosterone antagonists, ARNI, SGLT2 inhibitors) to reduce the risk of SCD and progressive heart failure [170, 454].

ESC IA (LoE C, GoR 5)

• Intense physical exertion, including participation in competitive sports, is not recommended for patients with DCM and a mutation in the LMNA gene [463, 464].

ESC IIIC (Level of Evidence C, Quality of Evidence 4)

ESC IIIA (Level of Evidence B, Quality of Evidence 2 – adults; Level of Evidence C, Quality of Evidence 5 – children)

ESC IIIA (Level of Evidence B, Quality of Evidence 1)

• ICD implantation*** is recommended for patients with DCM, symptoms of chronic heart failure (NYHA functional class II-III) and LVEF ≤ 35% on OMT ≥ 3 months with a life expectancy > 1 year [177, 254, 257, 459, 460, 461].

ESC IIaA (Level of Evidence B, Quality of Evidence 3 for adults; Level of Evidence C, Quality of Evidence 5 for children)

• ICD implantation*** is recommended for patients with DCM and a confirmed pathogenic LMNA mutation with an estimated 5-year risk of life-threatening ventricular arrhythmias ≥ 10% and the presence of non-sustained VT, LVEF less than 50%, or AV conduction disturbances [46, 462, 463].

ESC IIaB (Level of Evidence C, Quality of Evidence 5)

Comment. Mutations in the LMNA gene are associated with the early development of ventricular arrhythmias, conduction disturbances, a high risk of SCD, and progressive chronic heart failure. To assess the 5-year risk of life-threatening arrhythmias, it is recommended to use the calculator (not validated in the Russian population): https://lmna-riskvta.fr [46].

• ICD implantation*** is recommended for patients with DCM and an LVEF of less than 50% and two or more risk factors: syncope, myocardial late gadolinium enhancement on MRI, inducible sustained monomorphic VT during programmed stimulation, pathogenic mutations in LMNA, PLN, FLNC, and RBM20 genes [116, 170, 447, 449, 451, 463, 464, 465, 466, 467].

ESC IIaC (LoE C, GoR 5)

Secondary prevention of SCD in patients with DCM

• ICD implantation*** is recommended for patients with DCM and a history of cardiac arrest due to VF or VT, or in the presence of VT accompanied by hemodynamic instability [51, 111, 227, 245, 424, 469, 470].

ESC IB (Level of Evidence C, Grade of Recommendation 5)

• ICD implantation*** is recommended for adult patients with DCM and sustained paroxysmal VT without hemodynamic compromise [8].

ESC IIaC (Level of Evidence C, Grade of Recommendation 5)

• Patients over 18 years of age with DCM and an ICD who have recurrent symptomatic paroxysms of VT persisting despite beta-blocker therapy and optimal ICD programming*** are recommended the addition of amiodarone** or replacement of beta-blockers with sotalol** [8, 151, 192, 219, 245].

ESC IIaB (Level of Evidence C, Quality of Evidence 5)

Comment. In children, it is advisable to follow the same approach, despite the lack of sufficient evidence base.

• For patients with DCM and recurrent symptomatic sustained monomorphic VT or ICD*** shocks for the termination of monomorphic VT in cases where antiarrhythmic therapy is ineffective, contraindicated, or not tolerated, catheter ablation is recommended to be performed in experienced centers [51, 182, 471, 472, 473].

ESC IIaC (Level of Evidence C, Grade of Recommendation 5)

3.3.6 Arrhythmogenic right ventricular cardiomyopathy

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a hereditary disease characterized by fibrofatty replacement of the myocardium with characteristic manifestations in the form of ventricular arrhythmias (VA), chronic heart failure (CHF), and SCD [474].

Risk stratification and management of patients with arrhythmogenic cardiomyopathy

• For patients with suspected ARVC, cardiac MRI is recommended [475, 476, 477, 478].

ESC IB (LoE B, GoR 3)

• For patients with suspected or established diagnosis of ARVC, genetic testing is recommended [479, 480].

ESC IB (LoE C, GoR 4)

• For SCD risk stratification in patients older than 18 years with ARVC presenting with symptoms suggestive of ventricular arrhythmias, programmed electrical stimulation (PES) is recommended to be considered [481, 482].

ESC IIbC (LoE B, GoR 3)

• In first-degree relatives of patients with ARVC, ECG and echocardiography are recommended [8, 483, 740, 741].

ESC I C (LoE C, GoR 4)

Primary prevention of sudden cardiac death in patients with ARVC

• For patients with ARVC, refraining from intensive physical exercise is recommended for the prevention of SCD [483, 484, 485].

ESC IB (CGR B, LOR 3)

ESC IIbC (Level of Evidence B, Certainty of Evidence 3)

• For patients with sustained VT or non-sustained VT, beta-blocker therapy is recommended [488, 489, 490].

ESC IC (LoE C, GoR 3 for adults; LoE C, GoR 5 for children)

Comment. In children, it is advisable to adhere to the same approach despite the lack of sufficient evidence base.

ESC IIbC (LoE C, GoR 5)

Comment. In children, it is advisable to adhere to the same approach despite the lack of sufficient evidence base.

• ICD*** implantation is recommended for patients with a confirmed diagnosis of ARVC and arrhythmogenic syncope [488, 489, 490, 491, 492, 493, 494, 495, 496, 497, 498].

ESC IIaB (LoE B, GoR 3)

Comment. In children, it is advisable to adhere to the same approach despite the lack of sufficient evidence base.

• ICD*** implantation is recommended for patients with a confirmed diagnosis of ARVC and severe systolic dysfunction of the right or left ventricle [111, 481, 493, 495, 498].

ESC IIaC (LoE B, GoR 3)

Comment. Severe RV systolic dysfunction is defined as a change in fractional area change FAC ≤ 17% or a decrease in RV ejection fraction (RVEF) ≤ 35%; severe LV systolic dysfunction is defined as LVEF ≤ 35%.

• ICD*** implantation is recommended for patients with a confirmed diagnosis of ARVC who are symptomatic and have moderate RV systolic dysfunction (RVEF ≤ 40%) or LV systolic dysfunction (LVEF ≤ 45%) combined with non-sustained VT or sustained VT induced during PES [111, 482, 493, 498].

ESC IIaC (LoE B, GoR 3)

Secondary prevention of SCD in patients with ARVC

• ICD*** implantation is recommended for patients with VF or VT accompanied by hemodynamic instability [51, 495, 496, 498].

ESC IC (Level of Evidence C, Grade of Recommendation 4)

• ICD*** implantation is recommended for patients with ARVC and sustained VT without hemodynamic compromise [111, 496, 498].

ESC IIaC (LoE C, GoR 4)

Comment. In children, it is advisable to adhere toomed to the same approach despite the lack of sufficient evidence base.

• For patients with ARVC with indications for ICD therapy***, implantation of devices with the capability of programming ventricular antitachycardia pacing to terminate VT episodes and minimize the number of shocks is recommended [8, 498].

ESC IIaB (Level of Evidence C, Quality of Evidence 5)

Comment. In children, it is advisable to adhere to the same approach despite the lack of sufficient evidence base.

• For patients with ARVC and recurrent symptomatic sustained monomorphic VT or ICD*** shocks due to VT despite beta-blocker therapy, catheter ablation in an experienced center is recommended [51, 491, 499, 500, 501, 502].

ESC IIaC (LoE C, GoR 5)

• For patients with ARVC and recurrent symptomatic VT episodes when beta-blockers are ineffective, the administration of antiarrhythmic drugs for the termination of cardiac rhythm disorders is recommended [478, 488, 491, 500].

ESC IIaC (LoE C, GoR 4 – adults, LoE C, GoR 5 – children)

Comment. Antiarrhythmic drugs for the treatment of arrhythmias in ARVC have limited efficacy. It is advisable to use #amiodarone, which in isolated studies demonstrated higher efficacy compared to sotalol** (** in adult patients) [12, 17, 491, 500]. The efficacy of class I antiarrhythmic drugs registered in the Russian Federation has not been studied in patients with ARVC.

3.3.7 Hypertrophic cardiomyopathy

Arrhythmic death and the frequency of appropriate ICD shocks due to ventricular arrhythmias in the general population of patients with HCM are 1–2% and 0.8% per year, respectively [498]. SCD predominates as a cause of death in patients under the age of 60 years, whereas in the older age group, strokes and CHF are of primary importance [501, 502, 503, 504, 505, 506]. The 5-year SCD risk calculator (HCM risk-SCD) is available at: http://doc2do.com/hcm/webHCM.html (Appendix G3) [507].

Risk stratification and management of patients with HCM

• For patients with HCM, cardiac MRI with gadolinium (ATX V08CA Paramagnetic contrast media) is recommended for additional SCD risk stratification [508, 509, 510].

ESC IB (LoE C, GoR 4)

Comment. Late gadolinium enhancement ≥ 15% of LV myocardial mass is a predictor of SCD in adults.

• For patients with HCM, genetic testing and an initial consultation with a geneticist are recommended [503, 511, 512, 513, 514, 515, 516, 517].

ESC IB (Level of Evidence C, Grade of Recommendation 5)

Comment. Single or multiple sarcomeric mutations are an additional risk factor for SCD.

• For patients with HCM, participation in competitive sports is not recommended due to the high risk of SCD [503, 518, 519].

ESC IC (RR S, ELD 5)

Comment. Competitive sports refer to amateur or professional sports activities on a regular basis with participation in organized competitions.

• In first-degree relatives of patients with HCM, ECG registration and echocardiography are recommended [29, 740, 741].

ESC I C (LoE C, GoR 4)

• The 5-year risk of sudden death is recommended to be assessed at the initial patient evaluation, as well as every 1–3 years or upon changes in clinical status [8].

ESC IC (LoE C, SoR 5)

Primary prevention of SCD in patients with HCM

Расчет риска sudden cardiac death (SCD) over 5 years, proposed by the ESC (HCM risk-SCD), is presented in Appendix G3 (link: http://doc2do.com/hcm/webHCM.html) (not validated in the Russian population); the result is assessed as a % probability of SCD [507].

• ICD*** implantation is recommended for patients with HCM with a calculated 5-year SCD risk ≥ 6% [507, 520, 521, 522, 523].

ESC IIaC (LoE C, GoR 4)

• ICD*** implantation is recommended for patients with HCM aged ≥ 16 years with a calculated 5-year SCD risk from ≥ 4% to < 6% in the presence of at least one of the following risk factors:

a) extensive late gadolinium enhancement on cardiac MRI (≥ 15% of LV mass);

b) LVEF less than 50%;

c) abnormal blood pressure response during exercise stress testing (increase in blood pressure at peak exercise of less than 20 mmHg or a decrease of more than 20 mmHg);

d) apical LV aneurysm;

e) presence of a pathogenic sarcomeric mutation [512, 513, 515, 524, 525, 526, 527].

ESC IIaB (LoE C, GoR 4)

ESC IIbB (LoE C, GoR 4)

a) extensive late gadolinium enhancement on cardiac MRI (≥ 15% of LV mass);

b) LVEF less than 50%;

c) apical LV aneurysm [512, 513, 515, 524, 525, 526, 527].

ESC IIbB (LoE C, GoR 4)

Secondary prevention of SCD in patients with HCM

• ICD*** implantation is recommended for patients with HCM presenting with spontaneous sustained VT causing hemodynamic instability or sustained VF [111, 528, 529, 530, 531].

ESC IB (LoE C, GoR 4)

• ICD*** implantation is recommended for patients with HCM presenting with spontaneous sustained VT without hemodynamic compromise [8].

ESC IIaC (LoE C, GoR 5)

• For patients with HCM and recurrent symptomatic ventricular arrhythmias or repeated ICD*** shocks due to VT/VF, antiarrhythmic therapy is recommended [8].

ESC IIaC (LoE C, GoR 5)

Comment. Non-randomized studies have demonstrated the efficacy of amiodarone** in suppressing ventricular arrhythmias in adult patients with HCM [529, 530]. Beta-blockers may also be used for antiarrhythmic purposes in this group of patients, given their favorable effect on symptoms and reduction of left ventricular outflow tract (LVOT) obstruction [6, 505]. However, there is no evidence of the effect of antiarrhythmic therapy on reducing the risk of SCD.

ESC IIbC (C-GPR, 4 LoE)

• In children under 16 years of age with HCM and an estimated 5-year SCD risk ≥ 6% (based on the HCM Risk-Kids assessment), it is recommended to consider ICD implantation*** [520] (Appendix G4).

ESC IIaB (LoE C, GoR 4)

Comment: until recently there were limited data on primary SCD prevention in children with HCM. Currently, a risk score and SCD risk calculator have been developed, incorporating the assessment of such factors as unexplained syncope, maximum LV wall thickness, significant left atrial enlargement, LVOT pressure gradient, and nonsustained ventricular tachycardia. Unlike adults, age and a family history of SCD did not improve the predictive value of the model in children. The SCD risk calculator for children aged 1–16 years with HCM is available at the following link (validated on external data, but not validated in the Russian population): https://hcmriskkids.org

3.3.8 Restrictive cardiomyopathy

• ICD implantation*** is recommended for patients with transthyretin (TTR) amyloidosis or light-chain (AL) amyloidosis who have hemodynamically unstable paroxysmal ventricular tachyarrhythmias, after discussing the risks of SCD, non-arrhythmic cardiovascular death, and non-cardiac death [8, 533].

ESC IIaC (C-GPR, 5 LoE)

3.3.9 Neuromuscular diseases

Arrhythmias are common in neuromuscular disorders and can be the first manifestation of the disease. Myotonic dystrophy and Duchenne muscular dystrophy are the most prevalent, with the majority of patients dying before the age of 20. Conduction abnormalities and cardiac arrhythmias occur in most neuromuscular disorders.

Pacemaker implantation*** may be preferred in patients with Kearns-Sayre syndrome, Emery-Dreifuss muscular dystrophy, or limb-girdle muscular dystrophy with any degree of AV block, as they carry a significant risk of rapid progression to complete AV block [534].

ICD implantation***, rather than pacemaker implantation***, may be preferred in patients with Duchenne/Becker muscular dystrophy when CMR shows significant late gadolinium enhancement (ATC V08CA Paramagnetic contrast media). The benefit of ICD implantation must be balanced against the overall prognosis for certain disease subtypes, such as Duchenne muscular dystrophy.

• Patients with muscular dystrophies are recommended to undergo annual follow-up with at least a 12-lead ECG, even in the latent phase of the disease [535, 536, 537, 538, 740].

ESC IC (C-GPR, 4 LoE)

• Adult patients with neuromuscular disorders and ventricular arrhythmias or LV dysfunction are recommended to receive arrhythmia management similar to patients without neuromuscular disorders [539, 540].

ESC IC (C-GPR, 4 LoE)

• An EPS is recommended for patients over 18 years of age with myotonic dystrophy and palpitations or syncope suggestive of ventricular arrhythmias, as well as for patients after aborted SCD [541].

ESC IC (C-GPR, 4 LoE)

• ICD implantation*** is recommended for patients over 18 years of age with myotonic dystrophy and sustained ventricular tachycardia or aborted SCD not caused by bundle-branch re-entry ventricular tachycardia [542, 543].

ESC IC (C-GPR, 4 LoE)

• An EPS is recommended for patients over 18 years of age with myotonic dystrophy and sudden PR interval prolongation or QRS complex widening [483, 543, 544].

ESC IIaB (C-GPR, 4 LoE)

• An EPS is recommended for patients over 18 years of age with myotonic dystrophy and a PR interval ≥ 240 ms or QRS duration ≥ 120 ms, as well as for patients over 40 years of age with supraventricular arrhythmia or over 40 years of age with significant late gadolinium enhancement on CMR [543, 544].

ESC IIaB (C-GPR, 4 LoE)

• Patients over 18 years of age with myotonic dystrophy without AV conduction slowing and without syncope presumably associated with ventricular arrhythmias are recommended to undergo ICD implantation*** [543, 544, 545].

ESC IIaC (C-GPR, 5 LoE)

• Patients with myotonic dystrophy and palpitations highly suspicious of ventricular arrhythmias, and with induction of ventricular tachycardia not involving bundle-branch re-entry, are recommended to undergo ICD implantation*** [543, 544, 545].

ESC IIaC (C-GPR, 5 LoE)

• Patients with limb-girdle muscular dystrophy type 1B or Emery-Dreifuss muscular dystrophy with an indication for cardiac pacing are recommended to undergo ICD implantation*** [542, 545].

ESC IIaC (C-GPR, 5 LoE)

ESC IIbC (C-GPR, 5 LoE)

ESC IIbC (Level of Evidence C, Grade of Recommendation 4)

• Repeat evaluation of AV conduction and ventricular arrhythmia inducibility using invasive electrophysiological study is not recommended in patients older than 18 years with myotonic dystrophy without suspected arrhythmia or progression of conduction disturbances [541].

ESC IIIC (Level of Evidence C, Grade of Recommendation 4)

• In patients older than 18 years with symptomatic VT involving bundle branches, catheter ablation is recommended [540, 543].

ESC IC (C-GPR, 4 LoE)

• In patients with myotonic dystrophy older than 18 years undergoing catheter ablation of VT involving bundle branches, pacemaker implantation is recommended*** [540, 543].

ESC IC (C-GPR, 4 LoE)

3.3.10 Myocarditis

• Patients with confirmed or suspected acute myocarditis presenting with life-threatening ventricular arrhythmias are recommended to be transferred to a medical facility with appropriate expertise and experience in managing such patients [8, 546].

ESC IC (LoE C, GoR 5)

• In patients with hemodynamically significant sustained monomorphic ventricular tachycardia occurring in the chronic phase of myocarditis, ICD*** implantation is recommended [8, 111, 547].

ESC IC (LoE C, GoR 5)

• In patients with hemodynamically unstable VT or VF during the acute phase of myocarditis, it is recommended to consider ICD*** implantation prior to hospital discharge [8, 111, 547].

ESC IIaC (C-GPR, 5 LoE)

• In patients older than 18 years with symptomatic non-sustained or sustained ventricular arrhythmias in the acute phase of myocarditis, antiarrhythmic therapy is recommended (preferably amiodarone** and beta-blockers) [8].

ESC IIaC (C-GPR, 5 LoE)

• In patients older than 18 years with recurrent symptomatic VT who have a history of myocarditis, antiarrhythmic therapy is recommended [8].

ESC IIaC (C-GPR, 5 LoE)

• In post-myocarditis patients with symptomatic recurrent sustained monomorphic ventricular tachycardia or ICD*** shocks for sustained monomorphic ventricular tachycardia when antiarrhythmic drugs are ineffective, not tolerated, or undesirable, catheter ablation is recommended in experienced centers [8, 51].

ESC IIaC (C-GPR, 5 LoE)

• In patients with chronic myocarditis and hemodynamically significant sustained monomorphic ventricular tachycardia, ICD*** implantation is recommended [8, 111, 548].

ESC IIaC (C-GPR, 5 LoE)

• In patients older than 18 years with hemodynamically insignificant sustained monomorphic ventricular tachycardia occurring in the chronic phase of myocarditis, with preserved left ventricular function and a limited scar, catheter ablation is recommended to be considered as an alternative to ICD*** implantation, provided this strategy is discussed with the patient, non-inducibility of VT is achieved, and local electrograms characterized by conduction slowing are eliminated at the end of the ablation procedure [8, 548].

ESC IIbC (Level of Evidence C, Grade of Recommendation 4)

3.3.11 Sarcoidosis

Cardiac manifestations occur in approximately 5% of patients with sarcoidosis. Cardiac sarcoidosis typically manifests in three forms: left ventricular dysfunction, AV conduction disturbances, and ventricular arrhythmias. Glucocorticoid therapy is the mainstay of treatment for cardiac sarcoidosis, but its effect on ventricular arrhythmias has only been described in observational studies.

• In patients older than 18 years with cardiac sarcoidosis, ICD*** implantation is recommended if left ventricular ejection fraction is < 35% [8, 549].

ESC IB (Level of Evidence 5, Grade of Recommendation 4)

Comment. In children, it is advisable to follow the same approach despite the lack of a sufficient evidence base.

• In patients older than 18 years with cardiac sarcoidosis and an indication for cardiac pacing due to 2nd- or 3rd-degree AV block, ICD*** implantation is recommended regardless of left ventricular ejection fraction [8, 550].

ESC IIaC (LoE C, GoR 4)

Comment. In children, it is advisable to follow the same approach despite the lack of a sufficient evidence base.

• In patients older than 18 years with cardiac sarcoidosis, left ventricular ejection fraction > 35%, but significant late gadolinium enhancement on MRI, ICD*** implantation is recommended after resolution of the active inflammatory phase [8, 551].

ESC IIaB (LoE C, GoR 4)

Comment. In children, it is advisable to follow the same approach, despite the lack of sufficient evidence base.

• In patients older than 18 years with cardiac sarcoidosis, left ventricular ejection fraction of 35-50%, and insignificant late gadolinium enhancement on MRI, after resolution of the active inflammatory phase, an invasive electrophysiological study is recommended to attempt VT induction and risk stratification [8, 551].

ESC IIaC (LoE C, SoE 4)

• In patients older than 18 years with cardiac sarcoidosis, left ventricular ejection fraction of 35-50%, and induced monomorphic VT, ICD*** implantation is recommended [8, 552].

ESC IIaC (LoE C, SoE 4)

3.3.12 Lyme disease and Chagas disease

Lyme disease (borreliosis) is an infectious disease caused by the spirochete Borrelia burgdorferi. Vectors are ixodid ticks. Along with skin manifestations, inflammatory involvement of the nervous system and joints, the myocardium and pericardium can be involved in the pathological process. Conduction disturbances up to complete AV block are characteristic, and life-threatening ventricular arrhythmias have been described [553, 554, 555, 556]. The management of life-threatening ventricular arrhythmias in myocarditis is described in section 3.3.8, which is also relevant for Lyme disease.

Chagas disease is an infectious parasitic disease caused by Trypanosoma cruzi. It is transmitted by triatomine bugs and is prevalent in South and Central America. The gastrointestinal tract and the heart are primarily affected. In the acute phase, cardiac involvement manifests as acute myocarditis, while the chronic phase leads to cardiomyopathy with heart failure with reduced ejection fraction. The disease is characterized by both conduction disturbances, up to complete AV block, and life-threatening ventricular arrhythmias. ICD*** implantation may be justified for secondary prevention of sudden cardiac death in patients with Chagas disease, although studies on the benefits and risks of ICD*** use in these patients are contradictory.

• In patients over 18 years of age with Chagas disease, it is recommended to prescribe amiodarone** to reduce arrhythmic episodes in the presence of symptomatic premature ventricular complexes or ventricular tachycardia [557].

ESC IIaC (LoE B, GoR 3)

• In patients over 18 years of age with Chagas disease and recurrent symptomatic sustained monomorphic ventricular tachycardia or ICD*** shocks for monomorphic ventricular tachycardia, in whom antiarrhythmic therapy is ineffective, contraindicated, or not tolerated, catheter ablation is recommended in experienced centers [558].

ESC IIaC (LoE C, GoR 4)

• In patients over 18 years of age with Chagas disease and symptomatic ventricular tachycardia when antiarrhythmic therapy (amiodarone** and beta-blockers) is ineffective or not tolerated, it is recommended to consider ICD*** implantation [559].

ESC IIbC (LoE B, LoD 2)

3.3.13 Valvular heart disease

Valvular heart disease predisposes to sudden cardiac death both in the preoperative period and after valve surgery. Patients with valvular heart disease and residual left ventricular dysfunction after valve surgery who have received an ICD*** for primary prevention of sudden cardiac death have, taking into account individual characteristics, a similar rate of death and ICD*** interventions as patients after myocardial infarction and with dilated cardiomyopathy.

• Programmed ventricular stimulation and catheter ablation are recommended in patients over 18 years of age with aortic valve disease and sustained monomorphic ventricular tachycardia to identify and ablate ventricular tachycardia involving the bundle branches, especially when ventricular tachycardia occurs after aortic valve correction [560].

ESC IC (LoE 4, GoR C)

• In patients over 18 years of age with valvular heart disease and left ventricular dysfunction, including those after surgical correction, it is recommended to implant an ICD*** for primary prevention of sudden cardiac death, similar to the indications in dilated cardiomyopathy [111, 561].

ESC IC (LoE 4, GoR C)

3.3.14 Idiopathic ventricular fibrillation

The diagnosis of idiopathic ventricular fibrillation is established in survivors of sudden cardiac death, preferably with documented ventricular fibrillation, after exclusion of structural, metabolic, toxicological etiologies, and channelopathies. Additional information is provided by clinical evaluation (medical history, ECG and high precordial ECG recordings, exercise stress test, echocardiography) of first-degree relatives of patients with idiopathic ventricular fibrillation. Genetic testing is justified in patients to identify gene mutations associated with channelopathies and cardiomyopathies.

• ICD*** implantation is recommended for idiopathic ventricular fibrillation in patients over 18 years of age [8, 111].

ESC IB (Level of Evidence 5, Grade of Recommendation C)

Comment. In children, it is advisable to follow the same approach, despite the lack of sufficient evidence base.

• In patients over 18 years of age with recurrent episodes of ventricular fibrillation induced by repeated, morphologically similar premature ventricular complexes that are refractory to medical therapy, catheter ablation is recommended by experienced specialists [8].

ESC IIaC (LoE C, GoR 5)

3.3.15 Long QT syndrome (including acquired)

The average age at manifestation of clinical symptoms is 14 years. The annual rate of sudden cardiac death in patients with untreated congenital long QT syndrome ranges from 0.3 to 0.9 %, while syncope occurs in 5 % per year [363]. Mutations in 17 genes associated with congenital long QT syndrome have been identified, most of which encode subunits of voltage-gated ion channels: potassium, sodium, or calcium channels. Genetic screening detects pathogenic mutations in 75 % of congenital long QT syndrome cases within the three main genes (KCNQ1, KCNH2, and SCN5A for congenital long QT syndrome types 1, 2, and 3, respectively), accounting for 90 % of genotyped positive cases.

The following subtypes of congenital long QT syndrome are distinguished:

1. Autosomal dominant congenital long QT syndrome (prevalence 1 in 2500) without extracardiac manifestations.

2. Autosomal dominant congenital long QT syndromes with extracardiac manifestations, including:

a) Andersen–Tawil syndrome, which is increasingly considered an independent disease [573, 574, 575].

b) Timothy syndrome, characterized by QT interval prolongation, syndactyly, congenital heart defects, autism spectrum disorder, and dysmorphism [565].

3. Autosomal recessive congenital long QT syndrome (Jervell and Lange–Nielsen syndrome), combining extreme QT interval prolongation with congenital deafness [566].

The ESC Guidelines Task Force for the management of ventricular arrhythmias (2022) confirmed the diagnostic criteria for establishing a clinical diagnosis of congenital long QT syndrome [8]: QTc ≥ 480 ms or a risk score > 3 for congenital long QT syndrome (Appendix G1) [567]. In the presence of arrhythmogenic syncope or cardiac arrest, a QTc ≥ 460 ms is sufficient to diagnose congenital long QT syndrome.

Individual risk stratification is performed taking into account clinical, ECG, and genetic parameters [567, 568]. Prophylactic ICD*** use should be approached individually in all high-risk patients, particularly in women with type 2 congenital long QT syndrome genotype and QTc > 500 ms, in patients with QTc > 500 ms and signs of electrical instability, as well as in patients with a high-risk genetic profile (Timothy syndrome, Jervell and Lange–Nielsen syndrome, carriers of two or more mutations). It should also be considered that phenotype severity can be determined not only by the causative mutation, but also by the entire genetic landscape.

To date, there are no data indicating the prognostic significance of programmed ventricular stimulation with premature ventricular beats in patients with congenital long QT syndrome [53].

• The following lifestyle modification measures are recommended for all patients with diagnosed long QT syndrome:

a. Avoid medications that prolong the QT interval (list available at www.crediblemeds.org).

b. Correct electrolyte disturbances (hypokalemia, hypomagnesemia, hypocalcemia) that may develop due to diarrhea, vomiting, or metabolic disorders.

c. Avoid specific arrhythmia triggers (active swimming, especially in type 1 congenital long QT syndrome, and exposure to loud noises in type 2 of the disease) [569, 570].

GoR C, LoE 4

• Identification and elimination of causes of QT interval prolongation (primarily discontinuation of any medications capable of prolonging the QT interval, if used, correction of electrolyte disturbances, elimination of bradycardia) are recommended in patients with torsade de pointes polymorphic ventricular tachycardia [53, 568, 571, 572, 573].

ESC IIaC (LoE C, SoE 4)

• Beta-blockers are recommended in patients with congenital long QT syndrome for the prevention of sudden cardiac death [8, 569, 570, 573].

ESC IB (LoE C, GoR 4)

Comment. Preference is given to non-selective beta-blockers (propranolol**) [8, 574].

• The administration of beta-blockers for the prevention of sudden cardiac death is recommended in carriers of congenital long QT syndrome genetic mutations with a normal QT interval [573, 575, 576, 577].

ESC IIaB (LOCE B, LOE 2)

• In adult patients with congenital type 3 long QT syndrome and marked QT interval prolongation, it is recommended to consider the administration of #ranolazine (ATC C01EB Other cardiac preparations) in addition to beta-blockers to prevent recurrent ventricular tachycardia and sudden death, provided that during an acute drug test with this agent, the QTc interval shortens by more than 40 ms [8, 101, 578, 579, 580, 581, 582, 583].

RCC IIaC (GoR C, LoE 3)

• In adult patients with congenital type 3 long QT syndrome and marked QT interval prolongation, it is recommended to consider the administration of a sodium channel blocker (ATC C01BC Antiarrhythmics, class IC) #flecainide in addition to beta-blockers to prevent recurrent ventricular tachycardia and sudden death, provided that during an acute drug test with this agent, the QTc interval shortens by more than 40 ms [8, 101, 579, 580, 581, 582, 583, 584, 585].

RCC IIaC (GoR C, LoE 4)

Comment: adult doses are specified in Appendix A3, tables A3.2 and A3.4.

• Temporary cardiac pacing at a rate of 100 beats per minute or more is recommended in patients over 18 years of age to shorten the QT interval and prevent recurrences of torsade de pointes polymorphic ventricular tachycardia when magnesium sulfate** administration is ineffective [586, 587].

ESC IC (Level of Evidence C, Grade of Recommendation 4)

• For the termination of torsade de pointes polymorphic ventricular tachycardia, the use of class IA and class III antiarrhythmic drugs is not recommended [52, 102].

ESC IIIC (GoR C, LoE 4 – adults, GoR C, LoE 5 – children)

Comment. In children, it is advisable to adhere to the same approach despite the lack of sufficient evidence base.

• Intravenous administration of #magnesium sulfate** is recommended to prevent recurrences of torsade de pointes polymorphic ventricular tachycardia [52, 102].

ESC IC (GoR C, LoE 4 for adults; GoR C, LoE 5 for children)

Comment. Administration of #magnesium sulfate** often proves effective, including in patients with normal baseline blood magnesium levels. Doses for adults and children are specified in Appendix A3, tables A3.2 and A3.4.

• ICD*** implantation combined with beta-blockers is recommended for patients with LQTS who have survived cardiac arrest [8, 111, 588].

ESC IB (LoE C, GoR 4)

• ICD*** implantation combined with beta-blockers is recommended for patients with LQTS presenting with syncopal episodes and/or VT while receiving an adequate dose of beta-blockers [8, 111, 588].

ESC IIaC (LoE C, SoE 4)

• Left thoracoscopic cardiac sympathetic denervation is recommended in symptomatic patients with LQTS in the following cases:

a. Beta-blocker therapy is ineffective, poorly tolerated, or contraindicated.

b. ICD*** therapy is contraindicated or the patient refuses it.

c. Patients with an implanted ICD*** continue to experience multiple ICD*** shocks while on beta-blocker therapy [163, 361, 589, 590, 591].

ESC IIaC (LoE C, SoE 4)

ESC IIb C (LoE C, GoR 4)

3.3.16 Short QT syndrome (SQTS)

The syndrome is characterized by a shortened action potential duration in both atrial and ventricular cardiomyocytes, a reduced effective refractory period of the atria and ventricles, thereby creating conditions for life-threatening arrhythmias via a re-entry mechanism. Five genes associated with SQTS have been identified: KCNH2, KCNQ1, KCNJ2, CACNA1C and CACNB2b. However, the yield of genetic screening remains low (only 20%). The disease is fatal across all age groups, including infants in their first months of life, with a 40% probability of a first cardiac arrest by the age of 40. It is highly probable that SQTS is an underdiagnosed condition in the general population. Diagnosis in adults is established according to the criteria proposed by Gollob M. et al. [592] (Appendix G2).

In children and adolescents under 20 years of age, refined SQTS criteria include QTc < 316 ms, corrected J-Tpeak < 181 ms, and the presence of early ventricular repolarization [593].

Indications for ICD*** use are evaluated on an individual basis in each case, taking into account family history and the presence of a shortened QTc; however, current data are insufficient for general recommendations [594, 595].

To date, there is no evidence that EPS can predict arrhythmic events in patients with SQTS.

• ICD*** implantation for the prevention of SCD is recommended for patients with SQTS who:

a. Have survived cardiac arrest, and/or

b. Have documented spontaneous sustained VT [594, 595, 596, 597, 597].

ESC IC (Level of Evidence C, Grade of Recommendation 4)

ESC IIb C (LoE C, GoR 4)

ESC IIb C (LoE C, GoR 4)

Comment. Drug dosages for adults and children are specified in Appendix A3, Tables A3.1 and A3.3

3.3.17 Brugada syndrome

Brugada syndrome is a channelopathy with dominant inheritance and variable penetrance dependent on age and sex: clinical manifestations of the disease are more common in adults and 8 times more frequent in men than in women. VF occurs in middle age (manifestation peak occurs at 40 years), but can occur at any age, typically during rest or sleep.

Psychotropic drugs (ATC N05), certain AAAs, anesthetics, cocaine, excessive alcohol consumption, and fever are potential triggers for the emergence of a Brugada-type 1 ECG pattern and the onset of VF. Brugada syndrome is diagnosed in patients with ST-segment elevation characterized by a type 1 morphology ≥ 2 mm in one or more right precordial leads V1 and/or V2 placed in the second, third, or fourth intercostal space, occurring either spontaneously or following a provocative drug test with IV administration of a class IA antiarrhythmic drug (such as procainamide**), or upon recording an ECG in high precordial leads (intercostal spaces 1-2 ribs above the standard positions of electrodes V1 and V2).

• The following lifestyle modification measures are recommended for all patients with diagnosed Brugada syndrome:

a. Avoid medications that may provoke ST-segment elevation in the right chest leads (www.brugadadrugs.org).

b. Avoid the use of cocaine, cannabis, and heavy alcohol consumption.

c. Take immediate measures to lower body temperature in the event of fever of any origin [600, 601, 602, 603].

ESC IC (Level of Evidence C, Grade of Recommendation 4)

• ICD*** implantation is recommended for patients with diagnosed Brugada syndrome who have survived cardiac arrest and/or have documented spontaneous sustained VT [600, 601, 602, 603, 604].

ESC IC (Level of Evidence C, Grade of Recommendation 4)

• ICD*** implantation is recommended in patients with spontaneous type 1 ECG manifestations of Brugada syndrome and a history of syncopal episodes (likely of arrhythmic origin) [601, 602, 603, 604, 605].

ESC IIaC (LoE C, SoE 4)

ESC IIb C (LoE C, GoR 4)

• Catheter ablation of PVC foci triggering VF/VT and/or of the RVOT epicardial substrate is recommended in patients with Brugada syndrome presenting with recurrent ICD*** shocks refractory to drug therapy [605, 606].

ESC IIaC (LoE C, SoE 4)

3.3.18 Catecholaminergic polymorphic ventricular tachycardia

A rare inherited arrhythmogenic disorder characterized by adrenergically induced bidirectional and polymorphic VT (estimated prevalence 1 in 10,000). Two genetic types of CPVT have been identified: a dominant variant caused by mutations in the gene encoding the cardiac ryanodine receptor gene (RyR2), and a rare recessive variant caused by a mutation in the cardiac calsequestrin gene (CASQ2). Patients with CPVT exhibit a pronounced polymorphism of rhythm disturbances ranging from bradycardia, shortened PR interval, AV dissociation, supraventricular tachycardias to multifocal and polymorphic tachyarrhythmias, which frequently leads to delayed diagnosis of CPVT due to misinterpretation of syncope etiologies [607, 608, 609].

Independent prognostic factors for arrhythmic events in CPVT include disease manifestation in childhood, absence of beta-blocker therapy, and persistent complex arrhythmias. First-line therapy for CPVT includes non-selective beta-blockers (without intrinsic sympathomimetic activity) and lifestyle modification with physical activity restriction.

Left cardiac sympathetic denervation provides a certain therapeutic effect in CPVT patients who cannot tolerate beta-blockers; however, additional data and longer follow-up are required to quantify this effect. Patients who have survived cardiac arrest are recommended beta-blocker therapy and ICD*** implantation; if such treatment fails to achieve complete arrhythmia control based on stress testing results, combined AAT should be considered.

ICD*** implantation may be considered in CPVT patients who do not respond to beta-blocker treatment. When programming the ICD***, the VT detection duration should be increased, because shock delivery can be painful, promote an increase in sympathetic tone, and provoke repeated arrhythmia episodes, ultimately leading to a vicious cycle with recurrent VAs resulting in a fatal outcome.

• All patients with diagnosed CPVT are recommended to avoid competitive sports, heavy weight training, and stressful situations [610, 611].

ESC IC (Level of Evidence C, Grade of Recommendation 4)

• Beta-blocker therapy is recommended for arrhythmia treatment and SCD prevention in all patients with diagnosed CPVT given the presence of documented spontaneous or stress-induced VA [611].

ESC IC (Level of Evidence C, Grade of Recommendation 4)

• ICD*** implantation in addition to beta-blockers, with or without class I and III antiarrhythmic drugs, is recommended for arrhythmia treatment and SCD prevention in patients with diagnosed CPVT who have survived cardiac arrest, have a history of recurrent syncopal episodes or episodes of polymorphic/bidirectional VT despite OMT [610, 611, 612].

ESC IC (Level of Evidence C, Grade of Recommendation 4)

• Beta-blocker therapy is recommended for the patient's relatives for SCD prevention upon identification of genetic mutations, even in the absence of symptoms or VT manifestation [610, 611].

ESC IIaC (LoE C, SoE 4)

• #Flecainide therapy is recommended for recurrent syncope, polymorphic/bidirectional VT, or persistent exercise-induced PVCs in CPVT patients receiving the maximum tolerated dose of beta-blockers [111, 580, 606, 612].

ESC IIaC (LoE C, GoR 4)

Comment. Dosages for children: #flecainide (2 to 3 mg/kg).

ESC IIb C (LoE C, GoR 4)

3.3.19 Congenital heart defects

Risk stratification and primary SCD prevention

Regardless of the CHD type

• The use of ICD*** is recommended in CHD patients with syncope of unknown origin combined with severe ventricular dysfunction and/or inducible sustained VT/VF during EPS [51, 614, 615, 616].

ESC IIaB (LoE C, GoR 4)

• Implantation of an ICD*** is recommended in adult patients with CHD with biventricular physiology and systemic ventricular dysfunction (EF < 35%), symptomatic CHF on OMT with NYHA class II or III NYHA [51, 617, 618, 619].

ESC I C (LoE C, GoR 4)

• ICD*** implantation is recommended for CHD patients with suspected arrhythmogenic syncope who have either LV dysfunction or inducible sustained VT during EPS [51, 614, 618, 619, 620].

ESC IIaB (LoE C, GoR 4)

ESC IIbB (LoE C, GoR 4)

In patients after surgical correction of tetralogy of Fallot

• In patients after tetralogy of Fallot correction presenting with arrhythmia symptoms and NSVT, EPS including is recommended [616, 621, 623, 624].

ESC IIaC (LoE C, GoR 4)

• In patients after tetralogy of Fallot correction with arrhythmia symptoms and a positive EPS result, or with a combination of other risk factors and a positive EPS, ICD*** implantation is recommended [614, 618, 619, 622].

ESC IIaC (LoE C, GoR 4)

ESC IIbC (Level of Evidence C, GR 4)

• In patients with repaired tetralogy of Fallot undergoing repeat open-heart surgery or transcatheter pulmonary valve replacement, it is recommended to consider preoperative electrophysiological mapping and ablation/surgical transection of VT-related anatomical isthmuses before or during the procedure [625].

ESC IIbC (Level of Evidence C, GR 4)

Comment. The use of a transannular patch in patients with tetralogy of Fallot is associated with a lower risk of VA [625].

Secondary prevention of SCD and treatment of VA in CHD

Regardless of the CHD type

• In CHD patients with sustained VAs, it is recommended to assess residual and/or new anatomical abnormalities as a substrate for VA development [626, 627].

Level of Evidence C, GR 4

In patients after surgical correction of tetralogy of Fallot

• In patients with repaired tetralogy of Fallot who have sustained monomorphic VT (SMVT) or recurrent ICD shocks for SMVT, catheter ablation is recommended in experienced centers [628, 629, 630].

ESC I C (LoE C, GoR 4)

• In patients with repaired tetralogy of Fallot scheduled for repeat cardiac surgery who have confirmed SMVT, preoperative catheter mapping and ablation/surgical transection of VT-related anatomical isthmuses are recommended before or during the procedure [625, 627, 631].

ESC IIaC (LoE C, GoR 4)

• In patients with repaired tetralogy of Fallot and preserved biventricular function who have symptomatic SMVT, it is recommended to consider catheter ablation or surgical ablation in experienced centers as an alternative to ICD*** therapy [623, 628, 630].

ESC IIbC (Level of Evidence C, GR 4)

Catheter ablation of VT in patients with CHD

• In CHD patients with recurrent episodes of SMVT or ICD*** shocks that cannot be managed by ICD*** programming or antiarrhythmic drugs, catheter ablation is recommended in experienced centers [102, 632, 633, 634].

ESC IIaC (LoE C, GoR 4)

• Catheter ablation is recommended as an alternative to drug therapy for symptomatic SMVT in CHD patients with an ICD*** [102, 632, 633, 634].

ESC IIaB (LoE C, GoR 4)

• Catheter ablation and prophylactic antiarrhythmic drug therapy are not recommended for asymptomatic, infrequent VES in CHD patients with stable ventricular function [51].

ESC IIIC (CGR C, LOR 5)

• In patients with specific CHD variants (including atrial septal defect repair for transposition of the great arteries, Fontan procedure, and Ebstein anomaly) with SVT, it is recommended to identify and treat SVT with rapid ventricular conduction [619, 635].

ESC IIaC (LoE C, GoR 4)

3.4 Management aspects in special patient populations

3.4.1 Pregnant women and peripartum cardiomyopathy

Treatment of VT during pregnancy

• Beta-blocker therapy is recommended during pregnancy and the postpartum period in female patients with LQTS or CPVT [636, 637, 638, 639].

ESC I C (LoE C, GoR 4)

• Beta-blocker therapy is recommended during pregnancy in patients with ARVC [640, 641, 642].

ESC IIaC (LoE C, GoR 4)

• Oral administration of metoprolol**, #propranolol** or #verapamil** during pregnancy is recommended for long-term management of idiopathic sustained VT [643].

ESC IIaC (LoE C, GoR 5)

Comment: drug dosages during pregnancy are specified in Appendix A3, Table A3.1 and do not differ from those for the general population.

• If other antiarrhythmic drugs are ineffective, propafenone**, flecainide**, or sotalol** are recommended to prevent recurrent sustained VT during pregnancy (drug dosages are specified in Appendix A3, Table A3.1) [185, 643, 645].

ESC IIaC (LoE C, GoR 5)

• Emergency electrical cardioversion during pregnancy is recommended for terminating sustained VT, especially when accompanied by hemodynamic instability [644].

ESC IC (LoE C, GoR 4)

• Intravenous administration of beta-blockers, procainamide**, or overdrive pacing for VT suppression during pregnancy is recommended for emergency conversion of hemodynamically stable SMVT [643].

ESC IIaC (LoE C, GoR 5)

• In pregnant patients without structural heart disease, it is recommended to prescribe beta-blockers, Class IC antiarrhythmic drugs, direct-acting selective calcium channel blockers, or sotalol** when VES frequency exceeds 10% of total heartbeats according to Holter monitoring, and/or in the presence of poorly tolerated symptomatic VES, and/or with hemodynamic impairment [643, 645].

RSC IC (CGR C, LOR 5)

RSC IC (Level of Evidence C, GR 4)

Comment. In most cases, VES is not a contraindication to vaginal delivery and does not require medical treatment [645].

• If indicated, ICD*** implantation is recommended during pregnancy with optimal ionizing radiation shielding [647, 648].

ESC IC (LoE C, GoR 4)

ESC IIaC (Level of Evidence B, GR 3)

Comment. New-onset VT may manifest during pregnancy, and the risk of arrhythmia recurrence is higher in patients with pre-existing VT and CHD [650].

External electrical cardioversion (defibrillation) is safe at all stages of pregnancy; there is no evidence of fetal circulatory compromise or induction of preterm labor [644]. Fetal heart rate must be monitored regularly during all stages of external electrical cardioversion (defibrillation) [651].

When indicated, ICD*** implantation should be performed after 8 weeks of gestation with minimized fluoroscopy use, radiation protection, and an experienced operator [652]. The use of ultrasound guidance and/or 3D navigation systems helps reduce fluoroscopy time [647, 653].

In pregnant patients with an ICD***, routine device interrogation is recommended prior to delivery.

Pharmacological treatment of arrhythmias and HF in pregnant women may be similar to that in non-pregnant women, but drugs contraindicated in pregnancy, such as ACE inhibitors, ARBs/ARNIs, and renin inhibitors, should be avoided [643, 654, 655, 656]. The first trimester is associated with the highest teratogenic risk. Pharmacological therapy is recommended to be started as late in pregnancy as possible and at the lowest effective dose. Drug exposure in the second and third trimester may adversely affect fetal growth and development and may increase the risk of proarrhythmia. It is recommended to check the drugs and safety data before starting a new drug during pregnancy [611]. Well-tolerated drugs include sotalol**, #verapamil** (the drug dose is given in Appendix A3, Table A3.1.). Use is justified when the potential benefit outweighs the potential risk: metoprolol**, bisoprolol**, #carvedilol**, #lidocaine**, #propranolol**, #verapamil** intravenously [643]. Insufficient data: #ivabradine**, propafenone** (drug doses are given in Appendix A3, Table A3.1.) Contraindicated: #amiodarone**, #atenolol**, #diltiazem [643].

In LQTS (particularly type 2 LQTS), the risk of cardiovascular events increases significantly in the postpartum period (up to one year postpartum) [583]. Therefore, it is important to continue beta-blocker therapy during pregnancy and after delivery [636, 637, 638]. Continuation of beta-blocker treatment is recommended in LQTS and CPVT and should be considered in ARVC [639]. The additional risk of pregnancy in women with Brugada syndrome is unknown [577, 657].

Symptomatic tachyarrhythmia should be treated with catheter ablation prior to planned pregnancy. If catheter ablation is indicated in a pregnant patient, the procedure should be avoided in the first trimester, and procedures guided by electroanatomic mapping should be preferred [649, 658].

Arrhythmias Associated with Peripartum Cardiomyopathy

Peripartum cardiomyopathy (PPCM) is characterized by the de novo development of left ventricular systolic dysfunction and heart failure, and may be accompanied by ventricular tachycardia; it develops during the last months of pregnancy or the first 5 months postpartum and manifests as heart failure due to idiopathic left ventricular systolic dysfunction (LVEF usually < 45%) [643, 654]. A genetic predisposition to PPCM may be present in 20% of patients [650].

In patients with PPCM, early ICD*** implantation for the primary prevention of SCD should be approached with extreme caution, as spontaneous recovery often occurs postpartum [652].

In patients with PPCM, the use of bromocriptine** as specific therapy in addition to standard heart failure treatment has shown promising results in two clinical trials [659, 660, 661, 662].

3.4.2 Heart transplantation

• In patients over 18 years of age awaiting heart transplantation (HT), ICD*** implantation is recommended for the primary prevention of SCD [663, 664].

ESC IIaC (LoE C, GoR 4)

Comment. Patients on the heart transplant waiting list (HTWL) are at risk of SCD and have a high incidence of ventricular arrhythmias. This is especially important during prolonged stays on the HTWL; the average waiting time for transplantation worldwide is 8–16 months.

In children, it is advisable to adhere to the same approach despite the lack of sufficient evidence base.

• In patients over 18 years of age awaiting HT, it is recommended to consider the use of a wearable cardioverter-defibrillator [665].

ESC IIbC (Level of Evidence C, GR 4)

• In heart transplant recipients over 18 years of age with symptomatic ventricular arrhythmias, antiarrhythmic drug therapy is recommended as first-line treatment [198, 202, 203, 204, 664, 679]: Class IC antiarrhythmic drugs (propafenone**, diethylaminopropionylethoxycarbonylaminophenothiazine, lappaconitine hydrobromide**, flecainide), beta-blockers.

(Level of Evidence C, Grade of Recommendation 4)

Class III antiarrhythmic drugs (amiodarone**, sotalol**)

(Level of Evidence C, Grade of Recommendation 5)

and Calcium channel blockers (verapamil**).

(Level of Evidence C, Grade of Recommendation 4)

RSC IIaC

Comment. The use of antiarrhythmic therapy in heart transplant recipients requires special consideration and a personalized approach due to drug interactions with immunosuppressants, and requires additional monitoring of blood immunosuppressant concentrations and dose adjustment if their levels deviate from the target range. The most commonly used immunosuppressants, such as cyclosporine**, tacrolimus**, and sirolimus, are actively metabolized by the cytochrome P450 system (CYP3A4) and the P-glycoprotein transporter. Inhibitors or inducers of these enzymes can affect drug concentrations. Amiodarone**, diltiazem, verapamil**, sodium channel blockers (ATC C01BA, ATC C01BB, ATC C01BC) such as lidocaine** (IV), propafenone**, and other drugs can inhibit these enzymes and lead to increased concentrations of immunosuppressants. Immunosuppressants can affect QT interval prolongation; therefore, caution is recommended when using them concomitantly with sotalol**. Cyclosporine**, everolimus**, and azathioprine** increase QTc to a greater extent compared to tacrolimus**. Beta-blockers do not have drug interactions with immunosuppressive therapy; moreover, by providing heart rate control under conditions of sympathetic reinnervation, retrospective studies show they provide an additional effect in reducing mortality and cardiovascular morbidity [663].

• In heart transplant recipients with sustained VT, coronary angiography and endomyocardial biopsy are recommended to rule out acute rejection crisis and cardiac allograft vasculopathy [666].

RSC IIaC (LoE C, GoR 5)

• In heart transplant patients who develop cardiac allograft vasculopathy or have a resolved graft rejection crisis complicated by cardiac arrest and persistent left ventricular systolic dysfunction, it is recommended to consider ICD implantation [8, 667].

ESC IIbC (LoE B, LoD 2)

Comments. In heart transplant patients, the risk of SCD is 3 times higher compared to non-transplanted patients, which may be associated with sympathetic nervous system activation and an imbalance between sympathetic and parasympathetic innervation [664]. SCD is the cause of death after HT in 10% of cases [667, 668] and may be associated with graft rejection crisis and cardiac allograft vasculopathy [8, 65, 667]; therefore, ICD implantation may be appropriate in selected high-risk patients [8].

3.4.3 Sudden cardiac death in athletes

The incidence of SCD in athletes increases with age [669, 670].

In apparently healthy middle-aged and older athletes (> 35 years), it ranges from 2 to 6.3 per 100,000 person-years. In young and competitive athletes (≤ 35 years), the mortality rate is significantly lower than in the older age group, ranging from 0.4 to 3 per 100,000 participants per year [34, 670, 671]. Pre-participation cardiovascular screening enables early diagnosis of cardiovascular diseases in athletes before the onset of first symptoms [652]. In middle-aged/older athletes, coronary artery disease is the most common cause of death [672, 673].

Excellent survival rates with favorable neurological outcomes are achieved with the use of external electrical cardioversion (defibrillation) devices. Importantly, they must be used within the first 10 minutes of the onset of fatal ventricular arrhythmias [673, 674]. External electrical cardioversion (defibrillation) devices must be placed in accessible locations in gyms and sports arenas.

Athletes with a diagnosed cardiovascular disease associated with the risk of SCD need an assessment of their eligibility to continue sports participation in accordance with current eligibility guidelines.

• Athletes with a history of cardiovascular disease, abnormal physical examination findings, or ECG abnormalities are recommended to undergo a more in-depth evaluation, including echocardiography and/or cardiac MRI, to confirm (or exclude) the underlying disease [34, 675, 676, 741].

LoE C, GoR 5

• For cardiovascular screening in young athletes (under 35 years of age), it is recommended to perform a medical history intake, physical examination, and 12-lead ECG recording [34, 675, 740].

GoR C, LoE 4

• In middle-aged and older athletes (over 35 years of age), it is recommended to assess cardiovascular risk prior to participation in high-intensity physical activity [34].

GoR C, LoE 4

Competitive sports refer to regular amateur or professional athletic activities involving participation in organized competitions. When clinically significant ventricular arrhythmias are detected, it is advisable, at least temporarily, to suspend physical exertion. A 30–90 day detraining period followed by a re-evaluation of the cardiovascular system is justified. Non-genetically determined disorders associated exclusively with high workloads resolve in most cases.

It is advisable to train sports facility staff in cardiopulmonary resuscitation and the use of an external electrical cardioversion (defibrillation) device*** [674].

• Before participating in competitions, athletes are recommended to undergo a cardiovascular examination [34].

ESC IIaC (LoE C, GoR 4)

3.4.4 Wolff-Parkinson-White syndrome

In patients with Wolff-Parkinson-White (WPW) syndrome, the most common arrhythmia is AV re-entrant tachycardia (AVRT, 80%), followed by atrial fibrillation (AF) (20–30%). AF with conduction over an accessory AV pathway can lead to the induction of VF and SCD, which is the most dangerous manifestation of WPW syndrome. The risk of VF/SCD in untreated patients with WPW syndrome is 0.9–2.4 per 1,000 patient-years. The risk stratification approach for SVT and recommendations for the prevention of SCD are outlined in the 2020 National Guidelines for Supraventricular Tachycardias, revised in 2023.

Catheter ablation of the accessory AV pathway in WPW syndrome is the most effective treatment for the condition and for preventing SCD.

• In children with asymptomatic accessory conduction pathways, risk stratification is not recommended before the age of 8 years [678].

LoE C, GoR 5

3.4.5 Prevention of sudden death in the elderly

Biological age may vary to some extent depending on comorbidities. Comorbidities significantly affect the survival of patients with indications for ICD*** implantation, and a high comorbidity index is associated with a lower benefit of ICD*** implantation for primary or secondary prevention of SCD. Indications for ICD*** use in elderly patients should be based on an individual assessment of general status and comorbidities.

• In elderly patients with indications for primary prevention of SCD but a short expected remaining life expectancy, it is recommended to consider withholding ICD*** implantation [680].

ESC IIbB (LoE C, GoR 4)

3.5 Ventricular arrhythmias and risk of sudden death in children

3.5.1 Treatment of ventricular arrhythmias in children without structural heart disease

• In children with rare, asymptomatic VT who are presumed to have an extremely low risk of SCD and a benign disease course, the prescription of AADs is not recommended in most cases [51, 613].

ESC IB (LoE C, GoR 4)

Comment. Such children require outpatient follow-up for the early detection of developing symptoms and prevention of potential complications. VT treatment can be medical (AADs) and surgical (interventional). In turn, medical treatment consists of two directions: therapy aimed at the emergency termination of a VT episode and protective therapy to prevent the occurrence of episodes. The medical treatment regimen for VT depends on the severity of clinical manifestations (frequency, duration, and severity of VT paroxysms), the presence or absence of structural heart disease, SCD risk factors, age, the location of the arrhythmia substrate, and the efficacy of previously used drugs. To date, there is no evidence supporting the benefit of arrhythmia treatment in asymptomatic patients with preserved ventricular function. Furthermore, over time, especially in children, the burden of VES often decreases spontaneously. In selected patient groups, such as those who do not wish to continue follow-up, catheter ablation may be considered. In patients with a ventricular ectopic activity density of less than 10% (the proportion of VES among all heartbeats over 24 hours, according to 24-hour Holter ECG), re-evaluation may be appropriate if new symptoms develop or the patient's condition changes.

• Medical therapy or catheter ablation are recommended for children with frequent VES or VT that may cause ventricular dysfunction [51, 373, 613, 633, 634, 681, 682].

ESC I C (LoE C, GoR 4)

Comment. In general, the treatment of children should be the same as that of adults. Nevertheless, catheter ablation should be postponed in infants and young children due to the risk of complications and the relatively larger size of the ablation lesion compared to older children [655, 656].

• In children with incessant recurrent VT in the absence of central hemodynamics impairment, but with initial manifestations of arrhythmogenic myocardial dysfunction, it is recommended to administer antiarrhythmic drugs classes I and III, beta-blockers, and direct-acting cardiac selective calcium channel blockers [65, 66, 102, 343, 373, 633, 634, 679, 681, 682, 685, 686].

RSS IIaC (LoE C, GoR 4)

ESC IIaC (LoE C, GoR 5)

• Treatment of VT/VES with #verapamil** is not recommended in children under 1 year of age, especially if they have signs of heart failure or are already taking other drugs for the treatment of cardiac arrhythmias [51, 687, 688].

ESC IIIC (CGR C, LOR 5)

Comment. Cases of hypotension associated with #verapamil administration have been described**. It should be noted that in all these cases, patients either had signs of heart failure, or a #verapamil overdose, or were taking other drugs for the treatment of cardiac arrhythmias in combination with #verapamil** [687, 688].

• Catheter ablation in children with symptomatic idiopathic VT/VES from the RVOT area or #verapamil**-sensitive left ventricular fascicular tachycardia is recommended if medical therapy has proven ineffective or undesirable [51, 373, 634, 681, 687].

ESC IIaB (LoE C, GoR 4)

• Performing catheter ablation in an experienced center in children with symptomatic idiopathic LVOT VT, aortic valve area, or epicardial VT/VES is recommended if medical therapy has failed, or as an alternative to lifelong medical therapy [51, 373, 613].

ESC IIaB (LoE C, GoR 4)

• Catheter ablation of VT/VES is not recommended in children under 5 years of age or weighing less than 10 kg, except for cases of medical therapy failure and VT with severe hemodynamic impairment [51, 683].

ESC IIIC (LoE C, GoR 5)

3.5.2 Use of ICDs*** in children

• ICD*** implantation is recommended for the secondary prevention of SCD in children who survived cardiac arrest, provided that a thoroughly performed evaluation excludes the possibility of eliminating its causes, both in patients without structural heart disease and in the presence of congenital heart disease, cardiomyopathy, or inherited channelopathy [51, 614, 615, 616, 621].

ESC IB (Level of Evidence C, Grade of Recommendation 5)

Comment. Patients should undergo invasive hemodynamic evaluation and programmed electrical stimulation. Alternative treatment methods, such as catheter ablation or surgery, should be considered to eliminate VT. In cases where VT cannot be eliminated by these methods, ICD*** implantation is indicated [51, 614, 615, 616, 621].

SCD risk stratification in children with HCM aged 1 to 16 years inclusive is carried out using a recently proposed and validated risk calculator. Indications for ICD*** implantation in children with HCM are presented in Section 3.3.5.

3.5.3 Catheter ablation of VT in children

• Catheter ablation of the VT substrate (as first-line therapy or upon AAD failure) is recommended in children with hemodynamically significant VT or the presence of arrhythmogenic myocardial dysfunction [51, 343, 373, 609, 633, 634, 681, 682, 689].

RSS IIaC (LoE C, GoR 4)

ESC IIaB (LoE C, GoE 5)

• Catheter ablation is recommended in children with symptomatic RVOT VT [51, 343, 373, 634, 681, 682, 690].

ESC IIaB (LoE C, GoE 5)

Comment. Catheter ablation may be performed in children with polymorphic ventricular arrhythmia if one morphology dominates or when a trigger targeted for ablation is known. Catheter ablation of VT is not recommended in children with asymptomatic VT when the development of arrhythmogenic myocardial dysfunction is not expected. Catheter ablation of VT is not recommended in cases where VT is caused by transient factors such as acute myocarditis, drug toxicity, etc. [343].

4. Medical Rehabilitation and Sanatorium-Resort Treatment

Cardiac rehabilitation involves comprehensive, long-term programs including medical supervision, graded exercise therapy, risk factor modification, education, and counseling. These programs aim to limit the negative physiological and psychological manifestations of heart disease, reduce the risk of SCD and coronary events, and help control symptoms while improving the patient's physical and occupational status [691]. Patients whose outcomes improve with the inclusion in rehabilitation programs include patients with ACS, those who have undergone coronary artery bypass grafting, PCI, valve repair, or heart transplantation, as well as patients with stable angina [692]. Rehabilitation programs specifically for patients with ventricular arrhythmias do not currently exist as such. Rehabilitation measures should be implemented in accordance with the underlying disease causing the arrhythmia, if present [693].

Physical activity restriction is recommended for patients in accordance with their underlying cardiovascular disease [693], including the stage, severity, and degree of compensation of the primary condition.

• For patients older than 18 years following successful catheter ablation, it is recommended to consider restricting physical activity within the limits of household loads for 1 week to 1 month; the duration of restriction should be justified by the patient's clinical status and the likelihood of arrhythmia recurrence [694, 695, 696, 697].

RSC IIbC (LoE C, LoR 4)

Comment. Physical activity restriction must not contradict the restrictions regarding the underlying cardiovascular pathology. In the absence of complications from catheter ablation, special rehabilitation measures are not required; rehabilitation programs are based on the management guidelines for the underlying disease.

• Patients with severe complications of catheter ablation are recommended to be hospitalized as soon as possible [246, 698, 699, 700].

RSS IIaC (LoE C, GoR 4)

Comment. In the event of any complications following catheter ablation, including delayed ones, prompt hospitalization in a cardiology/cardiac surgery inpatient facility (urgent in-hospital consultation) is indicated to perform necessary diagnostic and therapeutic measures.

5. Prevention and Dispensary Observation

SCD prevention is a set of measures aimed at preventing or reducing the likelihood of SCD, carried out in individuals who have survived sudden cardiac arrest (secondary prevention) or in patients without prior episodes of SCA but possessing risk factors for SCD (primary prevention). Prevention of SCD risk must include modification of disease risk factors, as well as appropriate pharmacotherapy for primary and comorbid conditions [519]. Potential therapeutic pharmacological and non-pharmacological interventions are outlined in Section 3 of these guidelines and are considered part of SCD prevention.

Risk stratification

Vigilance for ECG and echocardiographic features of inherited arrhythmogenic disorders is an important part of clinical practice and allows for the timely identification of individuals at high risk for SCD. However, there is still no consensus on whether such a rigorous approach should be extended to mass population screening for SCD risk. Italy and Japan have introduced ECG screening systems to identify asymptomatic individuals with inherited arrhythmogenic disorders [554, 693, 701].

In Europe and the USA, pre-participation screening of athletes is mandatory according to the requirements of the International Olympic Committee, although a recent study in Israel showed no change in the incidence of SCD among professional athletes following the introduction of screening [702, 703, 704, 705].

ECG recording and analysis are performed for all individuals at high risk for SCD, as well as during routine health check-ups (dispensary medical examinations) of the adult population. In accordance with the order of the Russian Ministry of Health, 12-lead ECG recording is provided during routine health check-ups of the adult population:

- for men over 36 years of age and women over 45 years of age at each routine health check-up (i.e., once every 3 years);

- for men under 36 years of age and women under 45 years of age at their initial health check-up [706].

• Currently, population-wide ECG screening is not recommended due to a lack of data on its cost-effectiveness and an unknown number of false-positive and false-negative results [42, 707].

RSC IIIC (LoE C, LoR 4)

• First-degree relatives of sudden death victims are recommended to be informed about their existing risk and the need for evaluation by a cardiologist in cases where autopsy and analysis have revealed no obvious anomalies. Contact with relatives of sudden death victims should be handled with consideration of their psychosocial needs and using an multidisciplinary approach [582, 708, 709, 710, 711].

RSC IIaC (LoE C, LoR 3)

Comment. In approximately half of the cases, relatives of SCD victims are diagnosed with inherited arrhythmogenic disorders, primarily channelopathies (e.g., LQTS, Brugada syndrome, or CPVT), and less frequently with early manifestations of cardiomyopathies [primarily HCM and ARVC], as well as familial hypercholesterolemia. If autopsy of the deceased is not feasible in sudden unexplained death syndrome (SUDS), sudden arrhythmic death, or sudden infant death syndrome (SIDS), or when autopsy reveals no structural anomalies and toxicological analysis results are normal, close relatives should be informed of their existing risk of sudden death and the need for evaluation by a cardiologist. A family history of recurrent SUDS cases at a young age (under 40 years) or the presence of inherited heart diseases is an undeniable argument in favor of screening all family members.

• Screening of relatives of sudden death victims is recommended to follow the presented protocol (see comment), taking into account the cost-effectiveness and informative value of each method [87, 88, 710].

RSS IIaC (LoE C, GoR 4)

Comment. Several different protocols have been proposed for screening relatives of sudden death victims. All these protocols are based on a step-by-step approach, where the least costly diagnostic methods yielding the maximum amount of valuable information are used first, after which additional investigations are pursued based on the results and family history data. If structural or electrical abnormalities pointing to a specific diagnosis are identified during the evaluation, the standard diagnostic protocol for that condition must be followed. The first step in establishing a posthumous diagnosis, prior to screening the relatives of the deceased, is a thorough history taking. In cases of SCD in young individuals under 40 years of age, close relatives should first be evaluated to rule out cardiomyopathies and channelopathies. Assessment of prior cardiac symptoms (including syncope or seizures), a detailed review of the circumstances of death, and the collection and analysis of antemortem cardiological records are recommended. In individuals over 40 years of age, coronary artery disease risk factors (e.g., active or passive smoking, dyslipoproteinemia, hypertension, or diabetes mellitus) should be ruled out first. A three-generation pedigree of the deceased should be constructed, reflecting all cases of sudden death and relatives with heart disease. Archival medical records and/or autopsy results should be obtained whenever possible. Relatives with signs of heart disease, such as syncope, palpitations, or chest pain, should be evaluated first. If there is no family history of heart disease, screening of young children should be performed using at least an ECG and echocardiogram.

Echocardiography is advisable as a screening method for patients with a confirmed diagnosis of or suspected ventricular arrhythmias. Echocardiography should be considered in all patients with ventricular arrhythmias in whom arrhythmogenic right ventricular cardiomyopathy is suspected or present, as well as in patient groups at high risk for ventricular arrhythmias or SCD – for example, patients with DCM, HCM, and ARVC, as well as survivors of acute myocardial infarction and relatives of patients with inherited diseases carrying a high risk of SCD [65].

Dispensary follow-up (Active surveillance)

Follow-up care for patients with ventricular arrhythmias and an elevated risk of sudden cardiac death is carried out in accordance with the procedure for dispensary observation of adults (Order of the Russian Ministry of Health No. 168n dated March 15, 2022) at least twice a year with the assessment of the following parameters: Body weight measurement (BMI); Waist circumference determination; Smoking status; Blood pressure measurement on peripheral arteries; Heart rate measurement; Glomerular filtration rate (at least 1 time per year); Blood low-density lipoprotein cholesterol level testing (at least 2 times per year, as clinically indicated); ECG recording (at least 1 time per year); Echocardiography (at least 1 time per year); Holter monitoring of the cardiac rhythm (at least 1 time per year, as clinically indicated).

Patients with a high risk of cardiovascular complications or with the recurrence and/or increased frequency of episodes of cardiac rhythm disorders, the appearance of presyncopal and/or syncopal states are monitored by a cardiologist at an outpatient clinic, cardiodispensary, or an institution with available competencies in the diagnostics and treatment of cardiac rhythm and conduction disorders 4 times a year [712]. The follow-up of patients with an ICD is carried out in institutions with available capabilities or departments for the diagnostics and treatment of cardiac rhythm and conduction disorders during the first 6 months after implantation, thereafter at least 1 time per year, as well as after ICD discharges***.

It is advisable to consider the possibility of dispensary observation at least twice a year for patients with ventricular arrhythmias and an elevated risk of sudden cardiac death.

6. Organization of Medical Care

The type of care and the procedure for its provision depend on the etiology of ventricular tachycardia and concomitant pathology. Structural or functional heart pathology, especially if it progresses, may be the main indication for hospitalization.

Outpatient care options for patients with ventricular tachyarrhythmias are limited to the following cases:

1) Patients with chronic stable arrhythmias without hemodynamic disturbances: ventricular extrasystoles, non-sustained ventricular tachycardia, infrequent episodes of slow ventricular tachycardia;

2) Examination of patients without structural heart disease to identify latent heart pathology and criteria for the risk of sudden cardiac death;

3) Preparation for hospitalization when the patient's condition is stable;

4) Follow-up after surgical and interventional procedures, implantation of electronic devices (pacemaker***, implantable cardioverter-defibrillator***, triple-chamber [biventricular] implantable pacemaker*** / triple-chamber [biventricular] implantable cardioverter-defibrillator***).

Indications for planned hospitalization:

1) Newly onset symptomatic ventricular extrasystole accompanied by the development or significant worsening of heart failure;

2) Newly onset or recurrent episodes of sustained ventricular tachycardia without sudden cardiac death, requiring specialized elective treatment;

3) Progression of the underlying disease in cases where the arrhythmia is not hemodynamically significant;

4) Ineffectiveness of pre-hospital treatment for symptomatic chronic stable ventricular extrasystoles, non-sustained ventricular tachycardia, slow ventricular tachycardia.

Indications for emergency hospitalization

Mandatory hospitalization is required for patients who, against the background of ventricular tachyarrhythmias, exhibit signs of arterial hypotension, acute left ventricular failure, anginal syndrome, or impaired cerebral circulation. If myocardial infarction is suspected, the patient must be urgently delivered to a medical facility.

• Management of the patient after resuscitation measures is recommended in medical facilities with a multidisciplinary approach to intensive care and the capability to perform primary percutaneous coronary interventions, intracardiac electrophysiological studies, implantation of ventricular assist devices for mechanical circulatory support, including extracorporeal membrane oxygenation (ECMO), cardiovascular surgeries, and therapeutic hypothermia [115, 713, 714].

ESC IB (Level of Evidence C, Grade of Recommendation 5)

Comment: as a rule, level 3 inpatient facilities have such capabilities.

• Coronary angiography with possible subsequent angioplasty within the first 2 hours of hospitalization is recommended for high-risk patients with ST-segment elevation myocardial infarction, including those with life-threatening ventricular arrhythmias [398].

ESC IC (Level of Evidence C, Grade of Recommendation 5)

In case of cardiac arrest, hospitalization is required immediately after the termination of the episode and the restoration of normal cardiac activity. If resuscitation measures do not yield the desired effect, the patient is transported to the hospital unconscious. At the same time, artificial lung ventilation and chest compressions are performed continuously en route.

Patients with episodes of paroxysmal ventricular tachycardia should be hospitalized in case of no effect from emergency therapy, as well as in the presence of signs of acute left ventricular failure, impaired cerebral circulation, arterial hypotension, or anginal syndrome.

Individuals who have suffered an episode of ventricular tachycardia successfully terminated at the pre-hospital stage in the presence of structural heart disease or in the absence of the results of a cardiological examination, and who have concomitant diseases and a high risk of complications, are subject to hospitalization.

In refractory spontaneous circulation arrest and the ineffectiveness of advanced cardiopulmonary resuscitation (CPR) measures, it is advisable to consider the use of veno-arterial ECMO technology as part of advanced CPR (E-CPR).

Refractory circulatory arrest is currently defined as the failure to restore spontaneous circulation within 30 minutes of advanced cardiopulmonary resuscitation. From the standpoint of the clinical timeliness of E-CPR implementation, refractory circulatory arrest should be recognized in cases of unsuccessful resuscitation efforts within 20 minutes and/or after the completion of 3 full cycles of CPR with the administration of amiodarone**. The use of E-CPR is possible only in a medical organization that includes a department with experience in ECMO operations.

The decision on E-CPR must be made at the point of care, including the medical evacuation stage, if the estimated time from decision-making to system placement does not exceed 20–30 minutes. Thus, no more than 60 minutes should elapse from the moment of circulatory arrest to the moment of extracorporeal perfusion using ECMO. Exceeding this time leads to unsatisfactory technological outcomes in the form of adverse outcomes and irreversible post-hypoxic changes in the central nervous system. Strict adherence to the criteria for using veno-arterial ECMO during CPR (Appendix A3).

Provision of care for patients with sudden cardiac arrest in the emergency department

The procedure is presented in Appendix A3.

Indications for hospital discharge

The expediency of further hospital stay and the possibility of outpatient treatment are determined based on the results of the examination.

• Early (pre-discharge) assessment of left ventricular ejection fraction is recommended for all patients after myocardial infarction [251, 399, 715].

ESC IC (LoE C, SoR 5)

Patients may be discharged from the hospital in the following cases:

1) Performance of radical or palliative surgical and interventional treatment;

2) Implantation of a cardioverter-defibrillator***, provided that continued inpatient therapy for the underlying disease is not required;

3) Effective selection of antiarrhythmic drug therapy and treatment of the underlying disease;

4) Establishment of the diagnosis and prognostic significance of ventricular tachyarrhythmias that do not require urgent correction of antiarrhythmic therapy, surgical or interventional intervention, or ICD implantation***.

Other organizational approaches

In minors, it is advisable to record an ECG during routine preventive medical examinations at 1 year, 6, 15, and 17 years of age, as well as during preliminary medical examinations before admission to secondary and higher educational institutions, and to perform an echocardiography at 6 years of age [42, 706, 707, 716]. There is an approved procedure for undergoing medical examinations by minors. The genealogical method of analysis is especially important in young individuals suffering from recurrent episodes of loss of consciousness or having ECG abnormalities [716, 717].

Automated external defibrillators in crowded places

• Automated external defibrillators are recommended to be installed in public places where there is a significant concentration of people, which substantially increases the likelihood of a sudden cardiac death situation (e.g., in schools, airports, train stations, and stadiums), or in places where there is no other possibility of defibrillation (e.g., on trains, cruise ships, airplanes, etc.) [718, 719].

ESC IB (LoE C, GoR 4)

Comment. In most cases, cardiac arrest occurs outside the walls of a medical facility. With emergency defibrillation, the chances of restoring a normal rhythm and stable cardiac output are much higher than with delayed defibrillation [718, 719, 720].

ESC IIbC (LOE C, SOR 4)

May be used:

- Telemedicine counseling of patients.

- Remote monitoring of outpatient patients with implantable devices.

In providing care to patients with ventricular tachycardia and sudden cardiac death, it is advisable to distinguish levels of care with varying care capabilities. Given the life-threatening nature of ventricular tachycardia, in case of emergency hospitalization, it is advisable to refer patients to higher-level centers (Appendix A3).

Primary health care stage:

- resuscitation care

- cardioversion/defibrillation

Specialized care stage:

- antiarrhythmic therapy

- coronary angiography/revascularization

- intracardiac electrophysiological study

- catheter ablation of ventricular tachycardia

- implantable cardioverter-defibrillator implantation***

- cardiac resynchronization therapy pacemaker (biventricular)*** / cardiac resynchronization therapy implantable cardioverter-defibrillator (biventricular)***

Expert centers:

- coronary angiography/revascularization

- endomyocardial biopsy

- genetic testing

- intracardiac electrophysiological study

- catheter ablation of ventricular tachycardia

- implantable cardioverter-defibrillator implantation***

- cardiac resynchronization therapy pacemaker (biventricular)*** / cardiac resynchronization therapy implantable cardioverter-defibrillator (biventricular)***

- circulatory support

- heart transplantation

In certain constituent entities of the Russian Federation, dedicated care pathways for patients with ventricular tachyarrhythmias may be established, along with regional centers/registries for life-threatening tachyarrhythmias and sudden death.

ESC IIaB (LOCE C, LOE 5)

When determining indications for interventional or surgical treatment of cardiac rhythm or conduction disorders, as well as in complex cases, management tactics must be discussed with a specialist experienced in treating rhythm disorders. Such a specialist may be a cardiologist or a cardiovascular surgeon [744].

7. Additional Information

Shared decision-making

It is important to consider the patient's preferences for ventricular arrhythmia diagnosis and management decisions. Patient preferences regarding invasive therapy and acceptance of sudden cardiac death risk vary and may change throughout the course of the disease. A shared decision-making approach can be part of the overall management strategy for patients with ventricular arrhythmias and sudden cardiac death risk. The accepted definition of shared decision-making includes 4 components [720]: 1) at least 2 participants: physician and patient; 2) both parties share information; 3) both parties take steps to build a consensus on preferred treatment; 4) agreement on treatment implementation. Sharing a decision does not mean providing the patient with a list of treatment risks and benefits and asking them to make a choice (an approach some authors call "dumping" [696]). A recommendation based on both scientific evidence and an understanding of the patient's treatment goals, preferences, and values is essential for true shared decision-making. In addition, the possibility of deactivating an existing implantable cardioverter-defibrillator*** should be discussed with patients at the terminal stage of the disease.

Implantable cardioverter-defibrillators*** prolong life, as emphasized in many sections of these guidelines. Nevertheless, a patient with heart failure or severe non-cardiac disease may refuse implantable cardioverter-defibrillator*** replacement when faced with the prospect of progressive health and functional status decline. Unfortunately, research results show that patients are poorly informed when facing the risks, benefits, and subsequent burden of an implanted implantable cardioverter-defibrillator***. Patients with implantable cardioverter-defibrillators*** tend to overestimate their benefits and underestimate the associated risks [50, 721, 722]. Similarly, patients who refuse implantable cardioverter-defibrillators*** also often underestimate their personal risk of sudden cardiac death [75, 76]. Clinical decision-making studies show that physicians often overestimate benefits while playing down potential harms [722]. At the time implantable cardioverter-defibrillator*** replacement is indicated, the patient and physician should discuss together whether replacement still aligns with the treatment goal. What made sense at age 70 may not make sense at age 80. Patients may have a progressive disease or poor quality of life. All these factors can alter the risk/benefit ratio of the implantable cardioverter-defibrillator*** and influence patient preferences.

Recommendations on shared decision-making

• In patients with ventricular arrhythmias or an increased risk of sudden cardiac death, clinicians are recommended to adopt a shared decision-making approach in which treatment decisions are based not only on the best available scientific evidence, but also on the patient's personal health goals, preferences, and values [720, 723, 724].

ESC IB (Level of Evidence C, Grade of Recommendation 5)

• When considering the implantation of a new implantable cardioverter-defibrillator*** or replacement of an existing one due to battery depletion in a patient, it is recommended to inform him/her about the individual risk of sudden cardiac death and the risk of non-sudden death from heart failure or non-cardiac diseases, as well as the efficacy, safety, and potential complications of the implantable cardioverter-defibrillator*** in light of the patient's own health goals, preferences, and values [720, 723, 725].

ESC IB (Level of Evidence C, Grade of Recommendation 5)

Criteria for Evaluating the Quality of Medical Care

Quality evaluation criteria for primary health care in ventricular rhythm disorders or sudden cardiac arrest (ICD-10 codes: I46, I46.0, I46.1, I46.9, I47.0, I47.2, I47.9, I49, I49.0, I49.3, I49.4, I49.8, I49.9)

Quality evaluation criteria for specialized medical care in adults with ventricular rhythm disorders or sudden cardiac arrest (ICD-10 codes: I46, I46.0, I46.1, I46.9, I47.0, I47.2, I47.9, I49, I49.0, I49.3, I49.4, I49.8, I49.9)

References

Appendix A1. Working Group Composition

Steering Committee of the Working Group:

Mikhailov Evgeny Nikolaevich (Saint Petersburg)

Gizatulina Tatyana Prokopievna (Tyumen)

Lebedev Dmitry Sergeevich (Saint Petersburg)

Working Group Members:

Goluhova Elena Zelikovna (Moscow)

Kharlap Maria Sergeevna (Moscow)

Lebedeva Victoria Kimovna (Saint Petersburg)

Bagnenko Sergey Fedorovich (Saint Petersburg)

Artyukhina Elena Alexandrovna (Moscow)

Babokin Vadim Egorovich (Moscow)

Batalov Roman Efimovich (Tomsk)

Bereznitskaya Vera Vasilievna (Moscow)

Bondarev Sergey Anatolievich (Moscow)

Vasichkina Elena Sergeevna (Saint Petersburg)

Garkina Svetlana Vitalievna (Saint Petersburg)

Golitsyn Sergey Pavlovich (Moscow)

Davtyan Karapet Vovaevich (Moscow)

Duplyakov Dmitry Viktorovich (Samara)

Zaklyazminskaya Elena Valerievna (Moscow)

Zenin Sergey Anatolievich (Novosibirsk)

Ivanitskiy Eduard Alekseevich (Krasnoyarsk)

Ilydarova Rukijat Abdul-Gafurovna (Moscow)

Irtyuga Olga Borisovna (Saint Petersburg)

Komolyatova Vera Nikolaevna (Moscow)

Kostareva Anna Alexandrovna (Saint Petersburg)

Kuchinskaya Elena Andreevna (Moscow)

Layovich Lada Yurievna (Moscow)

Lyubimtseva Tamara Alekseevna (Saint Petersburg)

Makarov Leonid Mikhailovich (Moscow)

Mamchur Sergey Evgenievich (Kemerovo)

Medvedev Mikhail Markovich (Saint Petersburg)

Minnullin Ildar Pulatovich (Saint Petersburg)

Mironov Nikolay Yuryevich (Moscow)

Mitrofanova Lyubov Borisovna (Saint Petersburg)

Neminushchiy Nikolay Mikhaylovich (Moscow)

Popov Sergey Valentinovich (Tomsk)

Prasol Denis Mikhaylovich (Saint Petersburg)

Revishvili Amiran Shotaevich (Moscow)

Rzaev Farkhad Guseynovich (Moscow)

Romanov Aleksandr Borisovich (Novosibirsk)

Sitnikova Maria Yuryevna (Saint Petersburg)

Tatarskiy Roman Borisovich (Saint Petersburg)

Termosesov Sergey Arturovich (Moscow)

Todosiychuk Viktor Viktorovich (Tyumen)

Utsumueva Madina Dzhavatovna (Moscow)

Fedotov Petr Alekseevich (Saint Petersburg)

Khomenko Egor Aleksandrovich (Kemerovo)

Tsaregorodtsev Dmitry Aleksandrovich (Moscow)

Shkolnikova Maria Aleksandrovna (Moscow)

Shlevkov Nikolay Borisovich (Moscow)

Shlyakhto Evgeny Vladimirovich (Saint Petersburg)

Shubik Yury Viktorovich (Saint Petersburg)

Yashin Sergey Mikhaylovich (Saint Petersburg)

The Working Group members confirmed the absence of financial support/conflict of interest. In case of reporting a conflict of interest, the working group member(s) was/were excluded from the discussion of sections related to the conflict of interest area.

Appendix A2. Methodology for Developing Clinical Guidelines

These Guidelines are based on the previous version of the document, "Ventricular Arrhythmias. Ventricular Tachycardias and Sudden Cardiac Death" (2020), approved at the meeting of the Scientific and Practical Council of the Russian Ministry of Health (Minutes No. 38/2-3-4 dated October 16, 2020), the 2022 European Society of Cardiology Guidelines for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death, as well as the 2017 Clinical Practice Guidelines for Electrophysiological Studies, Catheter Ablation, and Implantable Antiarrhythmic Devices of the All-Russian Scientific Society of Clinical Electrophysiology, Arrhythmology, and Pacing (VROA), the 2015 Guidelines of the Society of Specialists in Urgent Cardiology on "Ventricular Arrhythmias in Adults", and the 2018 All-Russian Clinical Guidelines for the Control of Sudden Cardiac Arrest Risk and Sudden Cardiac Death, Prevention and First Aid, which were in turn developed based on the analysis of more than 20 years of experience from large-scale studies varying in objectives, protocols, and scope, conducted on various aspects of the diagnosis and treatment of ventricular tachyarrhythmias.

The Guidelines outline the core principles of diagnosis, sudden death risk stratification, and patient management, including across a range of clinical scenarios derived from randomized controlled trials. A comprehensive approach is employed, taking into account etiopathogenesis, individual characteristics of disease development and progression mechanisms, and the use of pharmacological, interventional, and surgical treatments.

Target audience for these clinical guidelines:

1. Cardiologist

2. Cardiovascular surgeon

3. X-ray endovascular diagnostic and treatment physician

4. Functional diagnostics physician

5. General physician

6. General practitioner (family physician)

ESC – throughout these clinical guidelines, recommendations corresponding to the European Society of Cardiology (ESC) guidelines are additionally marked with class indicators.

Because the Russian Society of Cardiology (RSC) is a constituent member of the European Society of Cardiology (ESC) and RSC members are also ESC members, all European guidelines are developed with the participation of Russian experts who act as co-authors. Thus, the existing ESC guidelines reflect the consensus of leading Russian and European cardiologists.

Consequently, national guidelines were formulated on the basis of ESC guidelines, taking into account national specifics, diagnostic and therapeutic practices, and the availability of specific medical care. For this reason, the RSC clinical guidelines incorporate international classes of recommendations to assess the necessity of a given recommendation statement, along with levels of evidence for these classes (Tables A2.1 and A2.2).

In cases where European guidelines lacked classes and levels of evidence, but in the opinion of RSC experts these statements were extremely necessary for implementation or, conversely, strictly not recommended for use, RSC experts—based on the rules for formulating recommendation classes according to the European Society of Cardiology guidelines—assigned the classes and levels themselves. In such instances, the ESC designation is replaced with RSC classes and levels assigned by RSC experts.

Additionally, a new grading system for Levels of Evidence (LoE) and Grades of Recommendation (GoR) for therapeutic, rehabilitation, preventive, and diagnostic interventions (Tables A2.3, A2.4, and A2.5) introduced in 2018 by the Center for Expertise and Quality Control of Medical Care of the Russian Ministry of Health has been integrated. Thus, the clinical guidelines developed by RSC experts utilize both scales in parallel (Tables A2.1, A2.2, A2.3, A2.4, and A2.5).

Table A2.1. Classes of recommendations according to the European Society of Cardiology (ESC) guidelines

Table A2.2. Levels of evidence according to the European Society of Cardiology (ESC) guidelines

Table A2.3. Scale for assessing levels of evidence (LoE) for diagnostic methods (diagnostic interventions)

Table A2.4. Scale for assessing levels of evidence (LoE) for prevention, treatment, and rehabilitation methods (preventive, therapeutic, and rehabilitation interventions)

Table A2.5. Scale for assessing grades of recommendation (GoR) for prevention, diagnostic, treatment, and rehabilitation methods (preventive, diagnostic, therapeutic, and rehabilitation interventions)

Procedure for updating clinical guidelines

The guideline update mechanism provides for their systematic review—at least once every three years or upon the emergence of new information on the management tactics of patients with this disease. The decision to update is made by the Russian Ministry of Health based on proposals submitted by professional medical non-profit organizations. The submitted proposals must take into account the results of a comprehensive assessment of medicinal products and medical devices, as well as the results of clinical approbation.

Appendix A3. Reference Materials

Related Documents

1. Order of the Ministry of Health of the Russian Federation No. 918n dated November 15, 2012, "On Approval of the Procedure for Providing Medical Care to Patients with Cardiovascular Diseases."

2. Order of the Ministry of Health of the Russian Federation No. 710n dated November 9, 2012, "On Approval of the Standard of Specialized Medical Care for Ventricular Tachycardia".

3. Order of the Ministry of Health of the Russian Federation No. 520n dated July 15, 2016, "On Approval of Medical Care Quality Assessment Criteria".

4. Order of the Ministry of Health of the Russian Federation No. 103n dated February 28, 2019, "On Approval of the Procedure and Timelines for the Development and Revision of Clinical Guidelines, Their Standard Template, and Requirements for Their Structure, Composition, and Scientific Validity of Information Included in Clinical Guidelines" (registered on May 8, 2019, No. 54588).

Drugs for the prevention of ventricular arrhythmias

Currently, the Vaughan Williams classification of antiarrhythmic drugs modified by B.N. Singh and D.C. Harrison is universally accepted.

This classification divides all currently known antiarrhythmic drugs into 4 classes based on their ability to:

1. depress depolarization (phase 0 of the action potential) in "fast-response" tissues;

2. block sympathetic influences on the heart;

3. increase action potential duration by slowing repolarization processes;

4. slow depolarization in "slow-response" tissues.

Each known antiarrhythmic drug exhibits one of the above effects as its dominant property, which determines its classification into a specific class.

1. Antiarrhythmic drugs, classes I and III (sodium channel blockers) (ATC: C01BA – Antiarrhythmic drugs, class IA, C01BB – Antiarrhythmic drugs, class IB, C01BC – Antiarrhythmic drugs, class IC).

2. Beta-blockers: class II antiarrhythmic drugs (ATC C07A - Beta-blocking agents).

3. Antiarrhythmic drugs, class III: potassium channel blockers (ATC C01BD - Antiarrhythmic drugs, class III).

Note: According to the Vaughan Williams classification modified by B.N. Singh and D.C. Harrison, sotatol** is a class III antiarrhythmic drug with concomitant non-selective beta-blocking activity. Under the ATC classification, it is categorized as a non-selective beta-blocker (C07AA). Throughout these guidelines, sotalol** is considered a class III antiarrhythmic drug, as the sole representative of beta-blockers that prolong the QT interval, which is critically important for its efficacy and, above all, safety.

4. Slow calcium channel blockers: class IV antiarrhythmic drugs (ATC C08D Selective calcium channel blockers with direct cardiac effects)

Table A3.1 Drugs for long-term therapy aimed at suppressing VES and preventing VT recurrence in adults

Day – 24 hours, mg/day – milligrams per day, VES – ventricular extrasystole, VT – ventricular tachycardia, VF – ventricular fibrillation, AF – atrial fibrillation, AFL – atrial flutter, SA – sinoatrial, AV – atrioventricular, LQTS – long QT syndrome, CPVT – catecholaminergic polymorphic ventricular tachycardia, RV – right ventricle, LVH – left ventricular hypertrophy, PICS – post-infarction cardiosclerosis, LVEF – left ventricular ejection fraction, CHF – chronic heart failure, FC – functional class, DM – diabetes mellitus, TdP – torsades de pointes. ATC - Anatomical Therapeutic Chemical classification system for drugs

Table A3.2 Drugs for terminating VT paroxysms in adults

Note: ¹ according to the E. Vaughan Williams classification modified by D. Harrison.

Abbreviations: AV — atrioventricular, BP — blood pressure, IV — intravenous administration, LVH — left ventricular hypertrophy, VT — ventricular tachycardia, ICD — implantable cardioverter-defibrillator, MI — myocardial infarction, LV — left ventricle, RV — right ventricle, LQTS — long QT syndrome, HF — heart failure, SMVT – sustained monomorphic ventricular tachycardia, AF — atrial fibrillation, CHF — chronic heart failure, ECG — electrocardiogram, TdP — torsades de pointes, WPW — Wolff-Parkinson-White syndrome. ATC — Anatomical Therapeutic Chemical classification system.

Table A3.3 Drugs for long-term therapy to prevent VT recurrence in children

Table A3.4 Drugs for terminating VT paroxysms in children

Pre-hospital emergency medical care protocol: Use of ECMO during CPR

1. Presence of a witness to sudden cardiac arrest (the cardiac arrest occurred in the presence of a person capable of recognizing it and calling for help).

2. Immediate initiation of basic life support (chest compressions must be started no later than 5 minutes from the presumed cardiac arrest);

3. Estimated interval from cardiac arrest to ECLS initiation of less than 60 minutes;

4. Estimated patient age not exceeding 70 years;

5. Availability of automated mechanical chest compression devices (suitable body habitus, no visible contraindications, device available in the medical team's equipment or at the medical facility);

6. Absence of previously known life-limiting comorbid conditions (terminal heart failure in non-candidates for heart transplantation, chronic obstructive pulmonary disease, terminal stage renal or hepatic failure, multiorgan failure with a SOFA score greater than 14 (Appendix G5), terminal stage oncological disease);

7. Absence of reliable data on moderate to severe aortic valve regurgitation;

8. Absence of trauma and ongoing hemorrhage;

9. Presence of any electrical cardiac activity (ventricular fibrillation, ventricular tachycardia, pulseless electrical activity, recurrent cardiac arrest);

10. Arterial blood lactate less than 18 mmol/L;

11. EtCO₂ greater than 10 mmHg;

12. PaO₂ greater than 50 mmHg;

13. SaO₂ greater than 85%;

14. Technical feasibility of cannulation;

15. Potentially reversible cause of cardiac arrest (cardiogenic shock of any type and origin, hypothermia, cardiotoxic drug poisoning, acute electrolyte disturbances not related to chronic disease).

Example checklist for verifying ECLS criteria during CPR:

Exclusion criteria for ECLS during CPR:

Procedure for providing care to patients with sudden cardiac arrest in the emergency department.

Upon admission to the emergency department of a patient in a state of clinical death that occurred outside a medical facility, the following are performed:

• Examination by an anesthesiologist-resuscitologist of the emergency department;

• ECG recording.

Laboratory examination:

• Acid-base balance and blood gas analysis (B03.016.011);

• Complete blood count (B03.016.002);

• Blood potassium test (A09.05.031); Blood sodium test (A09.05.030); Blood creatinine test (A09.05.020); Blood urea test (A09.05.017); Determination of alanine aminotransferase activity in blood (A09.05.042); Determination of aspartate aminotransferase activity in blood (A09.05.041); Blood total bilirubin test (A09.05.021); Blood glucose test (A09.05.023);

• Activated partial thromboplastin time (APTT) (A12.05.039); Determination of international normalized ratio (INR) (A12.30.014);

• Blood troponin I and T test (A09.05.193);

• Molecular biological blood test for Hepatitis C virus (A26.05.019), molecular biological blood test for Hepatitis B virus (A26.05.020), Determination of classes M, G antibodies (IgM, IgG) to Human immunodeficiency virus HIV 1 in blood (A26.06.048) and Determination of classes M, G antibodies (IgM, IgG) to Human immunodeficiency virus HIV 2 in blood (A26.06.049) or Test for classes M, G antibodies (IgM, IgG) to Human immunodeficiency virus HIV 1/2 + Agp24 in blood (A26.06.049.001), Determination of antibodies to Treponema pallidum in blood (A26.06.082);

• Blood group and Rh factor determination: Determination of main AB0 blood groups (A12.05.005), Determination of Rh factor (D antigen) (A12.05.006).

Instrumental diagnostics

• Ultrasound screening (FAST protocol): Echocardiography (A04.10.002), Ultrasound assessment of free fluid in the abdominal cavity (A04.30.004), Pleural cavity ultrasound (A04.09.001), Retroperitoneal ultrasound (A04.30.003), Complex pelvic ultrasound (transvaginal and transabdominal) (A04.30.010);

• Brain computed tomography (A06.23.004);

• Chest computed tomography with intravenous bolus contrast enhancement (A06.09.005.002);

• Abdominal computed tomography with intravenous bolus contrast enhancement (A06.30.005.003);

• Coronary angiography (A06.10.006).

Specialist consultations: as clinically indicated.

Treatment:

• continuation of advanced life support in full; if the cause leading to cardiac arrest is identified, pathogenetic therapy aimed at its elimination is performed;

• decision on the use of veno-arterial extracorporeal membrane oxygenation (VA-ECMO) as part of advanced life support (E-CPR).

Decision-making algorithm for the emergency medical team regarding the evacuation of a patient with sudden cardiac arrest

Additional online resources

- Regularly updated list of drugs affecting the QT interval duration: https://crediblemeds.org/

- Up-to-date information on drug side effects: https://www.drugs.com/

- Drugs increasing the risk of ventricular arrhythmias in patients with Brugada syndrome: http://www.brugadadrugs.org; in Russian: https://www.brugadadrugs.org/upload-dir/Drugs%20in%20Brugada%20syndrome%20letter%20RUSSIAN.pdf

Appendix B. Physician Action Algorithms

Figure 1. Algorithm for managing regular wide QRS tachycardia.

#procainamide** is used in the absence of severe heart failure, hypotension, acute myocardial infarction, end-stage renal disease, or signs of Brugada syndrome (for adult and pediatric doses, see Appendix A, tables A3.2 and A3.4).

Figure 2A. Management algorithm for patients with electrical storm or recurrent ICD shocks.

Note: ICD – implantable cardioverter-defibrillator***, AF – atrial fibrillation, SVT – supraventricular tachycardia, VA – ventricular arrhythmia, VT – ventricular tachycardia (adapted from [8]).

Figure 2B. Management algorithm for patients with electrical storm or recurrent ICD shocks (continuation of Figure 2A).

Figure 2C. Management algorithm for patients with electrical storm or recurrent ICD shocks (continuation of Figure 2A).

Ventricular arrhythmia burden (for VES and ventricular rhythms): the proportion of ventricular ectopic activity out of total heartbeats during the monitoring period on Holter ECG monitoring or according to an implantable antiarrhythmic device.

Figure 3. Clinical action algorithm for an initial episode of sustained monomorphic ventricular tachycardia.

Appendix C. Patient Information

Ventricular arrhythmias. Sudden cardiac death.

Core terminology

Ventricular arrhythmias or ventricular tachyarrhythmias are a general term for heart rhythm disorders in which the source of pathological electrical activity is located in the ventricular myocardium.

Sudden death is an unexpected, non-traumatic fatal event occurring within 1 hour of symptom onset in a seemingly healthy individual. If the death is unwitnessed, it is considered sudden if the victim was in satisfactory condition 24 hours prior to death.

Sudden cardiac death (SCD) is a term applied when sudden death occurs in a patient with a known congenital or acquired potentially fatal heart disease during life, or when cardiovascular pathology is identified postmortem and could have been the cause of death, or when no obvious extra-cardiac causes of death are found and the arrhythmia is the most likely cause.

Social significance

Sudden cardiac death as an irreversible outcome and result of sudden cardiac arrest accounts for up to 50% of all mortality outcomes in individuals aged 35–50 years, predominantly males, though recently there has been an upward trend in females and adolescents/young adults.

In nearly half of cases, cardiac arrest in individuals over 40 occurs without known heart disease, yet the majority have undiagnosed coronary artery disease (CAD). A decrease in the incidence of CAD and other heart diseases has reduced SCD cases by nearly 40%. There is a genetic predisposition to sudden death. The prognostic significance of a family history of sudden death has been documented—a single case of sudden death in the family nearly doubles the relative risk, while two cases increase the risk 9-fold.

Vigilance for electrocardiographic (ECG) and echocardiographic signs of hereditary arrhythmogenic disorders is an essential part of clinical practice, enabling timely identification of individuals at high risk for SCD. Screening first-degree relatives of sudden death victims helps identify individuals at risk, prescribe appropriate treatment, and thus prevent further cases of sudden death in the family.

Clinical manifestations

Clinical manifestations of ventricular tachyarrhythmias vary widely—from absolute absence of symptoms to palpitations, chest discomfort, retrosternal chest pain, dyspnea, dizziness, presyncope, and syncope. Palpitations, presyncope, and syncope are the three most critical symptoms requiring medical evaluation and further workup.

Modification of cardiovascular risk factors for adverse outcomes

Patients must be aware of their own and their family members' cardiovascular risk factors—smoking, overweight, psycho-emotional stress, sedentary lifestyle, and elevated cholesterol. The impact of these risk factors can be reduced. Modifiable risk factor correction is especially vital when patients and their family members have non-modifiable risk factors, which include: a family history of sudden cardiac death, early stroke, myocardial infarction, diabetes mellitus; male sex, older age, and physiological or surgical menopause in women are also included.

Risk factor modification must be implemented not only for the patient but also for family members through family-based primary prevention and education programs designed by the attending physician:

• Body mass index (Quetelet index) = body weight in kilograms / (height in m²);

• Waist-to-hip ratio (WHR): WHR = WC / HC, where WC (waist circumference) is the smallest circumference measured above the navel; HC (hip circumference) is the largest circumference measured at the buttocks level;

Basic recommendations for the patient and family

1. Sleep duration of at least 7 hours per night is considered adequate;

2. Body weight should approach ideal levels (BMI less than 25 kg/m²). To achieve this, daily caloric intake should range from 1500 to 2000 kcal depending on body weight and physical activity. Protein intake should be 1 g/kg of body weight per day, carbohydrates up to 50 g/day, and fats up to 80 g/day.

3. It is advisable to keep a food diary; the patient is strongly recommended to avoid fatty and sweet foods, and to prioritize vegetables, fruits, cereals, and whole-grain bread;

4. Restriction of salt intake to up to 5 g/day;

5. Foods rich in potassium should be consumed (fresh fruits, vegetables, dried apricots, baked potatoes);

6. Smoking must be stopped or limited;

7. Alcohol consumption should be limited, with a maximum intake of no more than 30 ml/day in terms of absolute ethanol;

8. Agreement with the attending physician on individually acceptable physical activities for the patient: walking, cycling, cross-country skiing, gardening;

9. Psycho-emotional stress at work and at home is controlled by a proper lifestyle. The duration of the working day and domestic workloads should be limited, and night shifts and business trips should be avoided;

10. Young male athletes must not abuse dietary supplements for muscle mass building and must exclude the use of anabolic steroids.

Advice for patients with an implanted cardioverter-defibrillator*** and/or cardiac resynchronization therapy device

• Exposure to strong magnetic and electromagnetic fields, as well as direct exposure to any magnets near the implantation site, is prohibited;

• Exposure to electric current is prohibited;

• Magnetic resonance imaging (MRI) is prohibited; exceptions include ICD and CRT-D systems (leads and device) that bear an MRI-conditional mark;

• Striking blows to the chest in the ICD/CRT-D implantation area and attempting to shift the device under the skin are prohibited;

• Driving a motor vehicle is prohibited during the first 3 months after ICD/CRT-D implantation, as well as for 3 months after an appropriate ICD discharge;

• The use of monopolar electrosurgery during surgical interventions (including endoscopic ones) is prohibited, and the use of bipolar coagulation should be minimized;

• The use of perforators, power drills, and lawn mowers should be limited; manual mowing and chopping firewood should be done with caution, and it is better to avoid this type of activity if possible;

• Excessive strain on the shoulder girdle is discouraged;

• Computers and similar devices, including portable ones, may be used;

• Any X-ray examinations, including computed tomography, may be performed;

• Housework or gardening work and the use of power tools are permitted, provided they are in good working order;

• Sports can be practiced, avoiding contact and collision sports;

• A patient with an ICD***/CRT-D must timely visit the physician for device interrogation using an appropriate programmer;

• A patient with an ICD***/CRT-D must know the name and model of the implanted device; it is highly advisable to always carry an ID card and informational data about the ICD***/CRT-D.

Advice for patients after interventional treatment of ventricular arrhythmias

• Restriction of moderate-to-heavy physical exertion for one to three months after interventional treatment of ventricular arrhythmias;

• Strict adherence to the activity regimen and medication recommendations;

• Regular visits to the attending physician with health status assessment and ECG monitoring at least once every 6 months;

• In the event of an arrhythmia attack accompanied by dizziness, weakness, fainting, or palpitations, call an ambulance; ECG documentation of the rhythm disturbances is desirable;

• Based on indications and the attending physician's recommendations, a follow-up echocardiogram and 24-hour Holter ECG monitoring may be necessary.

Principles of patient follow-up by the attending physician

• Scheduled visits to the attending physician to monitor health status are indicated on average once every 6 months;

• It is advisable for the patient to know the names and dosages of the medications they are taking;

• ECG monitoring is advisable during the visit to the attending physician;

• If health status worsens, an unscheduled examination by the attending physician is recommended.

Emergency conditions requiring an ambulance call

• In the event of an arrhythmia episode accompanied by dizziness, weakness, presyncope, fainting, or palpitations, calling an ambulance is indicated to monitor and stabilize the condition and determine indications for possible hospitalization;

• In the event of presyncope or fainting episodes, calling an ambulance is recommended to monitor and stabilize the condition and determine indications for possible hospitalization;

• In the event of ICD***/CRT-D discharges, calling an ambulance is recommended to monitor and stabilize the condition and determine indications for possible hospitalization;

• Patients who develop complications after catheter ablation are recommended to be urgently hospitalized in a specialized inpatient facility for necessary therapeutic and diagnostic measures.

Medical documentation

Patients are recommended to keep all discharge summaries from hospitals, electrocardiograms (especially those recorded at the time of rhythm disturbances), copies of laboratory tests and instrumental examination reports, and consultations from non-cardiologist physicians with their drug prescriptions. During a scheduled polyclinic visit, upon hospitalization, or when calling an ambulance, be sure to show these documents to the physician. Comparing your current data with previous indicators is very important and can be decisive for the correct diagnosis and treatment.

Appendix G. Assessment Scales, Questionnaires, and Other Evaluation Tools

Appendix G1. Modified diagnostic scale for long QT syndrome (LQTS) (Schwartz score)

The ESC expert panel developing the 2022 guidelines for the management of ventricular arrhythmias endorsed the use of the Schwartz score to establish a clinical diagnosis of LQTS [8]. The diagnostic criteria for congenital LQTS used are those developed in 1985, modified in 1993, and updated in 2006 and 2011 [567, 568].

Russian title: Modified diagnostic scale for LQTS (Schwartz score).

Original title: Modified long QT syndrome diagnostic score.

Source (official developer website, publication with validation): 2022 ESC Guidelines for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death / Zeppenfeld K., Tfelt-Hansen J., de Riva M., et al. // European Heart Journal. – 2022. – Vol. 21. – Is. 43(40). – P. 3997-4126; Diagnostic criteria for the long QT syndrome. An update / Schwartz P.J, Moss A.J, Vincent G.M, Crampton R.S. // Circulation. - 1993. - V. 88. - P. 782–784.

Type (underline):

- rating scale.

Purpose: a clinical tool to assess the probability of LQTS diagnosis.

Content (template):

Key (interpretation): A diagnosis of LQTS is confirmed if there are > 3 points.

Notes: the scale presents 4 groups of criteria for diagnosing LQTS, including ECG, clinical data, family history, and genetic test results. Each criterion corresponds to a certain number of points, which are summed up. With a total score of more than 3, the diagnosis of LQTS is established.

Appendix G2. Scale for the diagnosis of short QT syndrome (SQTS)

Russian name: SQTS diagnostic criteria.

Original name: SQTS Diagnostic Criteria.

Source (official developer website, validation publication): Gollob M. The Short QT Syndrome Proposed Diagnostic Criteria / Gollob M, Redpath C, Roberts J. // JACC. - 2011. - V. 57(7). - P. 802–12.

Type (underline):

- rating scale.

Purpose: a clinical tool to assess the probability of SQTS diagnosis.

Content (template):

Key (interpretation): 4 points or more indicate a high probability of SQTS, 3 points indicate an intermediate probability, and ≤ 2 points indicate a low probability.

Notes: The ECG must be recorded in the absence of factors causing QT shortening. The J point-T peak interval should be measured in the precordial lead with the highest T-wave amplitude. Clinical history: events must occur in the absence of a cause, including structural heart disease. Points can only be awarded for 1 cardiac arrest, documented polymorphic VT, or unexplained syncope. Family history: points in this section can only be obtained once. * To establish a diagnosis in the ECG section, at least 1 point must be scored, and the remaining points are supplementary to the ECG criterion.

Appendix G3. HCM risk-SCD. Sudden cardiac death risk assessment model in patients with hypertrophic cardiomyopathy

Russian name: SCD risk assessment scale in patients with HCM.

Original name: HCM risk-SCD.

Source (official developer website, validation publication): O’Mahony C., Jihchi F., Pavlou M. et al. // European Heart Journal. – 2014. – V. 35. – P. 2010-2020.

Website calculator: http://doc2do.com/hcm/webHCM.html

Type (underline): - rating scale.

Purpose: a clinical tool for predicting the risk of SCD in patients with HCM.

Content (template):

Appendix G4. HCM Risk-Kids. Sudden cardiac death risk calculator in children aged 1–16 years with hypertrophic cardiomyopathy

Until recently, there was little data on primary SCD prevention in children with HCM. Currently, an SCD risk scale and calculator have been developed, which include the assessment of factors such as unexplained syncope, maximum LV wall thickness, significant left atrial enlargement, LVOT pressure gradient, and NSVT. The SCD risk calculator for children aged 1-16 years with HCM is available via the link (validated on external data, but not validated in the Russian population): https://hcmriskkids.org

The model is validated only for children aged 1-16 years.

Russian name: SCD risk assessment scale in children aged 1-16 years with HCM.

Original name: HCM Risk-Kids.

Source (official developer website, validation publication): Development of a novel risk prediction model for sudden cardiac death in childhood hypertrophic cardiomyopathy (HCM risk-kids) / Norrish G., Ding T., Field E. et al. // JAMA Cardiology. – 2019. – V. 4. – P. 918–927. UDD 4 UUR

Website calculator: https://hcmriskkids.org

Type (underline): - rating scale.

Purpose: a clinical tool for predicting the risk of SCD in children aged 1-16 years with HCM.

Content (template):

Appendix G5. Sequential Organ Failure Assessment (SOFA) scale

The SOFA (Sequential Organ Failure Assessment) score is designed to objectively assess the degree of dysfunction of six major organ systems (respiratory, cardiovascular, hepatic, coagulation, renal, and central nervous system) in patients with suspected multiple organ dysfunction syndrome, particularly in intensive care settings. Each system is scored from 0 (normal) to 4 (severe dysfunction), and the total score reflects the severity of multiple organ dysfunction and correlates with mortality prognosis: the higher the total score, the higher the risk of an unfavorable outcome. SOFA is used for dynamic monitoring of the patient's condition, as well as for risk stratification in sepsis and other critical care conditions.

Russian name: Sequential Organ Failure Assessment scale.

Original name: SOFA (Sequential Organ Failure Assessment).

Source (official developer website, validation publication): Vincent J.L., Moreno R., Takala J. et al. The SOFA (Sepsis-related Organ Failure Assessment) score to describe organ dysfunction/failure. Intensive Care Med. 1996;22(7):707-710. Level of Evidence 4, Grade of Recommendation

Online calculator: https://medsoftpro.ru/kalkulyatory/sofa-scores.html

Type (underline): - rating scale.

Purpose: a clinical tool for objective assessment of the degree of dysfunction of six major organ systems (respiratory, cardiovascular, hepatic, coagulation, renal, and central nervous system) in patients with suspected multiple organ failure.

Content (template):

SOFA organ failure score grades:

Notes:

- Dysfunction of each organ is assessed separately over time.

- PaO₂ in mm Hg and FiO₁ in % 0.21 - 1.00.

- Adrenergic agents administered for at least 1 hour at a dose in mcg/kg/min.

- Mean arterial pressure in mm Hg = ((systolic BP in mm Hg) + (2 * (diastolic BP in mm Hg))) / 3.

- 0 points - normal; 4 points - greatest deviation from normal value

- Total SOFA score = Sum of points of all 6 parameters.

Interpretation:

- minimum total score: 0,

- maximum total score: 24,

- higher score indicates greater organ dysfunction,

- higher total score indicates more severe multiple organ dysfunction.