133. Acute heart failure - classification, etiology, pathogenesis, clinical manifestations.

Acute heart failure (AHF)

Definition

Acute heart failure is a rapid onset or sudden worsening of signs and symptoms of heart failure, leading to immediate compromise of cardiac output and/or congestion. It is a medical emergency requiring urgent treatment.

Classification

1. 1 By clinical presentation

Etiology

Cardiac causes

• Acute myocardial infarction (most common).
• Severe arrhythmias (e.g., ventricular tachycardia, atrial fibrillation with rapid ventricular response).
• Acute valvular dysfunction (e.g., papillary muscle rupture → mitral regurgitation).
• Acute myocarditis.

Increased hemodynamic load

• Hypertensive crisis.
• Massive pulmonary embolism.

Non-cardiac triggers (in chronic HF patients)

• Non-compliance with medications.
• Excess salt or fluid intake.
• Infections (especially pneumonia).
• Renal failure.
• Severe anemia.
• Thyrotoxic crisis.

Pathogenesis

1. 1 Acute decrease in cardiac output

Sudden loss of contractile function or severe arrhythmia → reduced forward flow.

1. 2 Increase in ventricular filling pressures

Backward congestion into pulmonary (left-sided failure) or systemic circulation (right-sided failure).

1. 3 Neurohormonal activation

Rapid sympathetic nervous system and RAAS activation → vasoconstriction, tachycardia, fluid retention → initially compensatory, but quickly worsening congestion and afterload.

1. 4 Pulmonary edema (if left-sided)

High hydrostatic pressure in pulmonary capillaries → transudation of fluid into alveoli → severe dyspnea and hypoxemia.

Clinical manifestations

Left-sided acute HF

• Severe dyspnea, orthopnea.
• Pink frothy sputum (pulmonary edema).
• Cyanosis.
• Cold, clammy skin (sympathetic activation).
• Crackles/rales on lung auscultation.
• Tachycardia, tachypnea.

Right-sided acute HF

• Jugular venous distension.
• Rapid development of peripheral edema.
• Hepatomegaly with right upper quadrant pain.
• Ascites (less common acutely).

Cardiogenic shock (severe AHF form)

• Severe hypotension (SBP <90 mmHg).
• Cold extremities, mottled skin.
• Oliguria.
• Altered mental status.

Summary table

Conclusion

Acute heart failure is a life-threatening syndrome often triggered by acute cardiac events or decompensation. Recognizing its clinical features rapidly is essential for prompt intervention.

Let me know if you'd also like a flow diagram showing sudden hemodynamic changes, or a "trigger factor summary" table!

Here’s a complete, clear, and detailed note on chronic heart failure (CHF), including classification, etiology, pathogenesis, and clinical manifestations — fully academic but easier to understand and memorize.