ECG criteria
- Inverted T wave in V1, V2, and V3 (or beyond) in individuals older than 14 years in the absence of complete right bundle branch block (QRS duration <120 ms) — major Task Force criterion
- Inverted T wave exclusively in V1 and V2 in individuals older than 14 years without complete RBBB — minor criterion
- Inverted T wave in V1–V4 in individuals older than 14 years in the presence of complete RBBB — minor criterion
- Epsilon wave — a reproducible low-amplitude signal between the end of the QRS and the onset of the T wave in leads V1–V3 — major criterion
- Terminal QRS activation duration (from S nadir to the end of QRS, including R') ≥55 ms in V1–V3 in the absence of complete RBBB — minor criterion
- Late potentials on signal-averaged ECG in the absence of complete RBBB (≥1 of three parameters: filtered QRS duration ≥114 ms, terminal low-amplitude signal <40 µV for ≥38 ms, root mean square voltage of the terminal 40 ms ≤20 µV) — minor depolarization criterion
- Sustained or non-sustained ventricular tachycardia with left bundle branch block morphology and superior axis — major (arrhythmic) criterion
- Sustained or non-sustained ventricular tachycardia with left bundle branch block morphology and inferior or indeterminate axis — minor criterion
- More than 500 ventricular premature complexes per 24 hours on Holter monitoring — minor criterion
What it looks like on ECG
The main abnormalities are localized in the right precordial leads V1–V3: these leads are most sensitive to depolarization and repolarization abnormalities frequently associated with right ventricular involvement, though they do not isolate a specific segment of its wall — the recording reflects the net vector of excitation.
| Sign | Leads | Criterion |
|---|---|---|
| T wave inversion | V1–V3 (±V4–V6) | in individuals older than 14 years, without RBBB |
| Epsilon wave | V1–V3 | reproducible low-amplitude signal after QRS, before the onset of T |
| Terminal QRS activation | V1–V3 | ≥55 ms from the S nadir to the end of QRS |
| Late potentials (signal-averaged ECG) | calculated across all leads | filtered QRS ≥114 ms, or terminal signal <40 µV for ≥38 ms, or RMS of the terminal 40 ms ≤20 µV |
The epsilon wave is the most specific yet rare visual sign: on a standard resting ECG, it is detected in a minority of patients, and its reproducibility upon visual assessment is limited. It is sought on a high-quality standard recording, sometimes utilizing modified or enhanced leads. A separate technique — signal-averaged ECG — quantitatively assesses ventricular late potentials based on three parameters of the filtered signal; this is an independent minor depolarization criterion, not equivalent to the visual search for an epsilon wave on a standard tracing, and is evaluated only in the absence of complete RBBB. More commonly, a patient simply exhibits T wave inversion in V1–V3 without a clear epsilon wave or pathological late potentials.
Secondary, informal signs (not included as standalone 2010 Task Force criteria) include a QRS width in V1 wider than in V6 and QRS fragmentation (multiple notches) in the right precordial leads — these have limited specificity and may draw attention, but they do not carry the diagnostic weight of a minor or major criterion.
Incomplete or complete right bundle branch block may occur in ARVC, but it is not an obligatory stage of disease progression; in complete RBBB, separate T wave inversion criteria are applied (V1–V4 instead of V1–V3). Between episodes, the rhythm is sinus, often with frequent right ventricular premature beats (left bundle branch block morphology). During sustained or non-sustained ventricular tachycardia, the axis of the complexes depends on the focus location: inferior axis — focus in the right ventricular outflow tract (minor criterion), superior axis — focus in the inferior/diaphragmatic wall of the RV (major criterion).
Mechanism
The underlying mechanism involves mutations in desmosomal genes (plakophilin-2, desmoplakin, desmoglein-2, desmocollin-2, plakoglobin, and others), which ensure mechanical coupling of cardiomyocytes. Disruption of intercellular contacts leads to myocyte apoptosis and necrosis, followed by fibro-fatty replacement, predominantly in the subepicardial and midmyocardial layers of the right ventricular free wall (triangle of dysplasia: outflow tract, apex, sub-tricuspid region). Fibro-fatty islands create zones of slowed and heterogeneous conduction — the substrate for re-entry loops and ventricular arrhythmias. This same conduction heterogeneity forms the epsilon wave and pathological late potentials (delayed depolarization of RV regions after the end of QRS) and T wave inversion (repolarization abnormality of the altered myocardium).
Causes
- inherited (autosomal dominant with incomplete penetrance) desmosomal gene mutation — the most common form
- Naxos disease (autosomal recessive, with palmoplantar keratoderma and woolly hair)
- mutations in non-desmosomal genes (TMEM43, lamin A/C — more frequently a biventricular phenotype)
- sporadic (no mutation identified) forms
- specifically: RYR2-associated catecholaminergic polymorphic ventricular tachycardia (CPVT) may phenotypically overlap with arrhythmogenic conditions and mimic them clinically, but RYR2 is not a typical ARVC gene — causative genes should be listed taking into account the arrhythmogenic cardiomyopathy (ACM) phenotype
Differential diagnosis
- Brugada syndrome — spontaneous or sodium channel blocker-induced type 1 (coved ST-segment elevation ≥2 mm followed by a negative T wave) recorded in at least one of leads V1 or V2 positioned in standard or 2nd–4th intercostal spaces, diagnostically significant in the appropriate clinical context; type 2 (saddleback) and type 3 are non-diagnostic on their own and require further evaluation (provocative testing, clinical data); structural heart disease is typically absent in Brugada syndrome
- Athlete's ECG and juvenile ECG pattern (juvenile T wave) — T wave inversion in V1–V3 can be physiological in children and adolescents; in a subset of adult Black athletes, a normal variant is not the T wave inversion itself, but a specific pattern: J-point elevation ≥1 mm with convex ST elevation and T wave inversion, typically not extending beyond V4. T wave inversion in an adult athlete without such a characteristic J-point/ST elevation is abnormal and requires the exclusion of an epsilon wave, QRS fragmentation, and structural abnormalities on echocardiography/MRI
- Right bundle branch block — QRS duration ≥120 ms with a typical rSR' morphology in V1; T wave inversion is secondary and expected; for ARVC diagnosis in the presence of RBBB, separate (less stringent) minor criteria are applied
- Right ventricular outflow tract tachycardia (idiopathic) — morphologically similar VT, but without structural myocardial changes, fibrosis, or epsilon waves; prognosis is favorable
- Myocarditis with RV involvement, cardiac sarcoidosis — visually similar ST-T changes and arrhythmias, differentiated by contrast-enhanced MRI, biopsy, and clinical presentation
Clinical significance and management
ARVC is an important cause of sudden cardiac death in young people and athletes, especially in hereditary forms and with intensive physical exertion; it often debuts with exercise-induced ventricular tachycardia or ventricular fibrillation. ECG findings are part of the multiparametric 2010 revised Task Force diagnostic criteria, which also include RV structural alterations on echocardiography/MRI, biopsy data, depolarization/repolarization abnormalities (including signal-averaged ECG), arrhythmias, and family/genetic history; the diagnosis is established by the sum of major and minor criteria from different categories rather than the ECG alone. The 2010 Task Force criteria remain the primary working tool for classic ARVC with predominant right ventricular involvement, but they were specifically designed for this form and do not adequately cover left-dominant and biventricular phenotypes. For modern diagnosis of the entire spectrum of arrhythmogenic cardiomyopathy (ACM), Padua 2020 criteria and current expert recommendations are additionally considered, which include the assessment of left ventricular involvement and biventricular forms. When ARVC is suspected based on the ECG, the physician refers the patient for echocardiography and contrast-enhanced cardiac MRI, Holter monitoring, and gathers a family history of sudden death; exercise testing and signal-averaged ECG are considered as indicated in a specialized center, with exercise testing performed under controlled conditions due to the risk of arrhythmia provocation. When a pathogenic or likely pathogenic variant is identified in the proband, genetic counseling and targeted cascade testing of relatives are performed; if the result is negative in a relative, regular cardiological follow-up according to a familial protocol is clinically justified. Patients are restricted from intensive physical activity (competitive sports), which in itself reduces the risk of arrhythmic death. In case of a high risk of sudden death, implantable cardioverter-defibrillator placement is considered; antiarrhythmic therapy and catheter ablation are used to control symptomatic ventricular tachycardia.
Common interpretation errors
- interpreting physiological juvenile T-wave inversion in V1–V3 in young people as pathology without considering age and clinical context
- searching for an epsilon wave on a standard resting ECG and interpreting its absence as ruling out the diagnosis — the sign is rare and often requires special leads or a signal-averaged ECG
- failing to measure terminal QRS activation in V1–V3, thereby missing a minor criterion despite a normal-appearing QRS width
- confusing T-wave inversion in ARVC with reciprocal changes in inferior myocardial infarction or with the Brugada pattern
- evaluating the ECG in isolation without correlating it with structural data (echocardiography, MRI) and family history
1. Which ECG sign belongs to the major diagnostic criteria for ARVC?
An epsilon wave—a reproducible low-amplitude signal after the QRS complex and before the onset of the T wave in V1–V3—is a major Task Force criterion for ARVC.
2. In a healthy person of what age can T-wave inversion in V1–V3 be a physiological variant (juvenile pattern)?
The Task Force criteria for T-wave inversion are applied in individuals older than 14 years; in younger individuals, such inversion may be a physiological juvenile pattern.
3. What ventricular tachycardia morphology is typical in ARVC?
VT in ARVC originates from the affected right ventricle, and therefore has a left bundle branch block morphology.
Frequently asked questions
Is an epsilon wave mandatory for the diagnosis of ARVC?
No, this is a major criterion, but it is far from present in all patients, especially in early stages. The diagnosis is established by the sum of Task Force criteria from different categories (ECG, structural data, biopsy, arrhythmias, genetics, history) rather than a single sign.
How to distinguish T-wave inversion in ARVC from normal in young people?
In children and adolescents, especially before puberty is complete, an inverted T wave in V1–V3 can be physiological. After 14 years of age, such inversion is considered a Task Force criterion only if conditions are met (absence of RBBB, appropriate leads) and no other confounding causes are present. ARVC is additionally supported by an epsilon wave, pathological late potentials, prolonged terminal QRS activation, right ventricular arrhythmias, structural changes on echocardiography/MRI, and a family history of sudden death.
Is ARVC dangerous?
Yes, this is an important cause of sudden cardiac death in young people and athletes, especially in hereditary forms and with intensive physical exertion, due to ventricular tachycardia and ventricular fibrillation, which are frequently provoked by physical activity.
What ventricular tachycardia is typical for ARVC?
Monomorphic VT with left bundle branch block morphology originating from the affected right ventricle; the axis depends on the localization of the fibrosis focus—superior axis when the focus is in the inferior RV wall, inferior when in the outflow tract.
Is a single ECG sufficient for the diagnosis of ARVC?
No. ECG findings, including signal-averaged ECG data, are just one category of Task Force diagnostic criteria; confirmation requires data from echocardiography or cardiac MRI, Holter monitoring, and sometimes biopsy and genetic testing.
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Related terms
More in the «Channelopathies and Cardiomyopathies» section
Sources
- Surawicz B., Knilans T. Chou's Electrocardiography in Clinical Practice, 6th ed.
- Goldberger A.L. Clinical Electrocardiography: A Simplified Approach
- Marcus F.I. et al., Revised Task Force Diagnostic Criteria for ARVC, 2010
- Orlov V.N. Guide to Electrocardiography
Educational material for medical students and physicians. Does not replace clinical guidelines and physical examination; the ECG must always be interpreted in conjunction with the clinical picture.