Congestive Heart Failure

Congestive Heart Failure

• Cardial decompensation occurs due to a decrease in cardiac output (CO), leading to a deterioration of blood supply to tissues.
• Preload is determined by the tone of the venous system, while afterload is determined by the arterial system and peripheral resistance (PR).

Cardial Decompensation Reasons

• Systolic dysfunction: muscle strength decreases, leading to decreased cardiac output and perfusion, often caused by coronary stenosis, arrhythmia, or cardiomyopathy.
• Diastolic dysfunction: inability to relax due to left ventricular stiffness, leading to pulmonary blood flow disorders and peripheral edema, often caused by hypertension, valvular dysfunction, or pericarditis.

Compensatory Processes

• Increased sympathetic activity: increased heart rate (β1 receptor) and vasoconstriction (α1 receptor), which worsens the condition further.
• RAAS (Renin-Angiotensin-Aldosterone System): increased angiotensin II activity leads to vasoconstriction, remodeling, and left ventricular hypertrophy, and aldosterone mobilization causes Na and water retention, resulting in edema.

NYHA Classification

• Divided into 4 stages based on the onset of symptoms:
  • I: physical activity does not cause symptoms
  • II: physical activity causes mild symptoms, which disappear at rest
  • III: even mild physical activity causes shortness of breath
  • IV: symptoms of heart failure occur even at rest

Treatment

• Lifestyle changes, diet, and regular exercise
• Drug treatment:
  • In milder cases (NYHA I, II): aim to stop compensatory processes
    • Beta1 receptor blockers (bisoprolol, nebivolol): reduce increased sympathetic activity
    • ACE inhibitors (perindopril, telmisartan): prevent vasoconstriction and remodeling effect
    • Diuretics (indapamide, eplerone): reduce preload
  • In more severe cases:
    • Cardiac glycosides (digitalis preparations): increase contractility, positive inotropic effect, and negative chronotropic effect

Digitalis Preparations

• Mechanisms of action:
  • Inhibit Na/K-ATPase, increasing Na and Ca levels, and contractility
  • Decrease renin release in the kidney
  • Negative dromotropic effect: slow conduction in the atrial chamber
  • Increase heterotropic stimulation: can cause ventricular arrhythmias
• Side effects:
  • Loss of appetite, nausea, vomiting, headache, fatigue, dizziness, bradycardia, extrasystole, bigeminia, AV block, and ventricular tachycardia
• Treatment of overdose:
  • Drug withdrawal
  • Potassium replacement
  • ECG control
  • Treatment of arrhythmias
  • Antibody (Digibind) to bind to free digoxin molecules and reverse cardiotoxic effects

This quiz covers the concept of congestive heart failure, including its causes, effects on cardiac output, and factors affecting cardiac decompensation.