CHF Classification: Two Coordinate Systems
To assess the severity of heart failure in Russia, two scales are traditionally used. They evaluate the problem from different perspectives: hemodynamics and exercise tolerance.
NYHA functional classification focuses on quality of life:
- Class I: everyday physical activity causes no symptoms.
- Class II: slight limitation, ordinary activity causes dyspnea.
- Class III: marked limitation, symptoms occur with minimal exertion.
- Class IV: complete inability, CHF symptoms persist even at complete rest.
Strazhesko and Vasilenko classification reflects the staging of structural and hemodynamic changes:
- Stage I (latent): hemodynamics at rest is normal; tachycardia and dyspnea appear only upon exertion.
- Stage II (manifest): blood congestion persists at rest. It is divided into period A (congestion only in the pulmonary circulation) and period B (total congestion in both circulatory loops).
- Stage III (dystrophic): irreversible organ changes, cardiac cachexia (wasting).
Pathogenesis: The Vicious Circle of Heart Failure
The development of CHF is based on long-term myocardial damage (e.g., in coronary artery disease, arterial hypertension, or valvular heart disease). Due to cardiomyocyte death, cardiac output decreases, leading to hypoperfusion of target organs.
The body tries to compensate for the oxygen shortage, but these mechanisms ultimately destroy the heart:
- SNS activation: cardiac hypoperfusion triggers the sympathetic nervous system. Persistent tachycardia develops, which depletes the myocardium.
- RAAS activation: the kidneys, receiving inadequate blood flow, secrete renin. This leads to potent vasoconstriction (increased resistance to ejection — afterload) and sodium and water retention (increased circulating blood volume and preload).
The heart, forced to work with double effort, begins to undergo remodeling. Pressure overload leads to concentric hypertrophy (wall thickening). Volume overload leads to eccentric hypertrophy (chamber dilation), which rapidly progresses to cardiosclerosis and reduced myocardial elasticity.
Clinical Presentation: Symptoms of Congestion
The symptoms of CHF directly depend on which circulatory loop venous congestion predominates in.
Left ventricular failure syndrome (pulmonary circulation): Patients complain of severe dyspnea (the leading symptom), which worsens in the supine position (orthopnea). Attacks of cardiac asthma may occur. Objective findings include tachypnea, non-sonorous moist rales in the lower lung fields, and possible hydrothorax.
Signs of right ventricular failure (systemic circulation):
- Jugular venous distension in the neck.
- Peripheral firm edema (on the legs and sacrum).
- Hepatomegaly (enlarged liver) and a positive hepatojugular reflux.
- In severe stages, ascites, portal hypertension, and cardiac cirrhosis of the liver develop.
Diagnostics and Modern Treatment Principles
The diagnosis is established based on complaints, medical history, and instrumental data.
- Echocardiography (EchoCG): the gold standard for assessing ejection fraction (EF) and chamber sizes.
- Radiography: reveals cardiomegaly (cardiothoracic index > 50%) and pulmonary venous congestion.
- Magnesium test: a simple test to assess blood flow velocity.
Treatment is built on two levels. The tactical goal is to relieve symptoms (dyspnea, edema). The strategic goal is to slow myocardial remodeling and prolong the patient's life.
The backbone of therapy consists of ACE inhibitors, diuretics to control fluid retention, and vasodilators. Non-pharmacological methods play an important role: physical activity restriction and a strict low-salt diet.
Briefly: answers to topical questions
What parameters are evaluated during EchoCG for CHF diagnosis?
EchoCG for CHF diagnosis evaluates structural changes, chamber sizes, and myocardial function.
- Chamber dilation (first the left ventricle, then the remaining chambers);
- Increase in left ventricular end-systolic and end-diastolic dimensions;
- Decreased ejection fraction (EF);
- Myocardial mass index;
- Relative wall thickness;
- Left ventricular volume index;
- Resting E/e' ratio;
- Systolic pulmonary artery pressure;
- Resting tricuspid regurgitation velocity.
What are the main drug classes used for pathogenetic therapy of CHF?
CHF therapy utilizes a basic four-component regimen (quadruple therapy) including the main drug classes.
- ACE inhibitors or valsartan + sacubitril (ARNI); in case of ACE inhibitor intolerance, ARBs;
- Beta-blockers;
- Aldosterone antagonists (MRAs);
- SGLT2 inhibitors: dapagliflozin or empagliflozin.
Digoxin can only be used as an adjunct to basic therapy.
Left loop — lungs (dyspnea), right loop — periphery (leg edema, liver).
What else to study on this topic
- Mechanisms of myocardial remodeling (eccentric and concentric hypertrophy).
- Features of diastolic heart failure.
- ECG changes during the development of heart failure.
- Differential diagnosis of pleural effusions in CHF.
- Evolution of CHF pharmacotherapy and the role of ACE inhibitors.
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