Right-sided heart failure

1. Concept

Right-sided heart failure (RHF / cor pulmonale) occurs when the right ventricle cannot pump enough blood to the lungs against increased pulmonary resistance/pressure. The RV hypertrophies, then fails → blood backs up into the systemic venous system → peripheral congestion/edema.

2. Causes

• Left-sided heart failure — the most common cause (backward pressure transmits through lungs to RV).
• Pulmonary hypertension, pulmonary embolism.
• Lung disease: COPD, emphysema, interstitial fibrosis, cystic fibrosis.

3. Acute vs chronic cor pulmonale

	Acute	Chronic
Cause	Massive pulmonary embolism (>50% obstruction)	Prolonged pressure overload (emphysema, interstitial fibrosis)
RV change	Dilation only (no hypertrophy)	RV (± RA) hypertrophy; dilation if it fails

4. Clinical features

• Systemic venous congestion: dependent edema (feet, ankles, legs), ascites, hepatomegaly, raised JVP.
• Dyspnea, cough/wheeze, chest discomfort, tachycardia.
• Diagnosis: ECG, chest X-ray, echocardiogram; confirm with MRI/CT/catheterization.

💡 High-yield: RHF = systemic congestion (peripheral edema, ascites, hepatomegaly, ↑JVP) — contrast LHF (pulmonary congestion). Most common cause = left-sided HF. Cor pulmonale = RHF from lung disease: acute (massive PE → dilation only) vs chronic (COPD/fibrosis → RV hypertrophy).