HFrEF vs HFpEF

Heart failure with reduced ejection fraction (HFrEF): EF <40%; previously called systolic dysfunction. The left ventricle dilates and loses contractile function. Most common causes: ischemic cardiomyopathy (CAD, prior MI), dilated cardiomyopathy (idiopathic, alcohol, peripartum, viral myocarditis, doxorubicin). Biomarkers: BNP/NT-proBNP elevated. CXR: cardiomegaly, pulmonary vascular congestion, Kerley B lines, pleural effusions. Key point: GDMT (guideline-directed medical therapy) dramatically reduces mortality in HFrEF — 4 drug classes proven to improve survival. Heart failure with preserved ejection fraction (HFpEF): EF ≥50%; previously called diastolic dysfunction. Ventricle is stiff/non-compliant; it fills poorly. Most common causes: hypertension (#1), diabetes, obesity, age, atrial fibrillation. Treatment: limited evidence for mortality benefit; manage underlying causes, diuretics for symptoms. SGLT2 inhibitors (empagliflozin/dapagliflozin) now show mortality benefit in HFpEF.

NYHA Functional Classification

NYHA Class I: No symptoms with ordinary activity; no limitation. Class II: Mild symptoms (fatigue, dyspnea) with moderate exertion; comfortable at rest. Class III: Marked limitation; symptoms with minimal exertion (walking one block); comfortable at rest. Class IV: Symptoms at rest; cannot perform any activity without discomfort. Correlates with prognosis: Class IV HFrEF has ~50% annual mortality without transplant/LVAD. NYHA class guides therapy: GDMT started at all stages; ICD/CRT at Class II-III with EF ≤35%.

The 4 Pillars of GDMT for HFrEF

Guideline-directed medical therapy for HFrEF reduces mortality by 40-50% when all four classes are used: (1) ACE inhibitor or ARB (or ARNI — sacubitril/valsartan = Entresto): reduces afterload + neurohormonal activation; ARNI superior to ACEi for mortality reduction; avoid in pregnancy, bilateral RAS, angioedema. (2) Beta-blocker (carvedilol, metoprolol succinate, bisoprolol — the THREE evidence-based beta-blockers for HF): reduces heart rate, prevents remodeling, anti-arrhythmic. Start low and titrate up. Never start during acute decompensation. (3) MRA — mineralocorticoid receptor antagonist (spironolactone or eplerenone): reduce mortality in Class II-IV HFrEF; watch for hyperkalemia + gynecomastia (spironolactone). (4) SGLT2 inhibitor (dapagliflozin or empagliflozin): newest pillar; reduces hospitalizations and mortality in both HFrEF and HFpEF; glycosuric/osmotic diuresis.

Acute Decompensated Heart Failure: LMNOP

Acute decompensated HF (ADHF) presents with flash pulmonary edema, severe dyspnea, orthopnea. Management mnemonic LMNOP: L = Lasix (furosemide IV) — diuresis reduces preload; dose at least 2.5x oral daily dose IV. M = Morphine — reduces anxiety, vasodilates (controversial, some data suggests harm — use cautiously). N = Nitrates (nitroglycerin) — potent venodilator → reduces preload; avoid if systolic BP <90 or use of PDE5 inhibitors. O = Oxygen — titrate to SaO2 >94%; consider CPAP/BiPAP for respiratory failure. P = Position (sit upright) — reduces venous return and preload. Additional: Nesiritide (recombinant BNP) for vasodilation in severe cases. Avoid starting new beta-blocker during acute decompensation (can worsen acute HF). Note: if cardiogenic shock develops (cold, hypoperfused, hypotensive) → inotropes (dobutamine, milrinone) + urgent cath if ischemic etiology.