Preparatory Mindset

Heart failure is the INABILITY of the heart to pump enough blood to meet metabolic demands. Classify as: left vs right, systolic (↓ EF) vs diastolic (preserved EF). The most common cause is CAD → MI → systolic HF. Key compensatory mechanisms (Frank-Starling, sympathetic activation, RAAS activation) initially help but eventually worsen the condition.

Core Concepts

• Heart Failure = heart can't pump enough to meet metabolic demands.


• HFrEF (systolic, EF<40%): ↓ contractility — most common after MI.


• HFpEF (diastolic, EF≥50%): impaired relaxation — hypertension, aging, obesity.


• Left HF → pulmonary congestion (dyspnea, orthopnea, PND).


• Right HF → systemic congestion (JVD, hepatomegaly, pedal edema).


• Compensation: Frank-Starling (↑ preload → ↑ contractility, but eventually → pulmonary congestion), Sympathetic activation (↑ HR, ↑ contractility, but → ↑ O₂ demand), RAAS activation (↑ volume, ↑ vasoconstriction, but → ↑ afterload, fibrosis)..

High-Yield Points

• Reduced EF (HFrEF): EF <40% — systolic dysfunction


• Preserved EF (HFpEF): EF ≥50% — diastolic dysfunction (relaxation impaired)


• New York Heart Association (NYHA) functional classification


• ACEi/ARBs + β-blockers = cornerstone of HFrEF therapy


• Spironolactone: aldosterone antagonist for advanced HF


• Digoxin: symptom relief but NO mortality benefit

Topic Summary

Heart failure can be left (pulmonary congestion) or right (systemic congestion), systolic (↓ EF) or diastolic (preserved EF). Compensatory mechanisms (RAAS, sympathetic) initially maintain output but eventually cause harm.