heart failure with preserved ejection fraction

HFpEF results from impaired left ventricular relaxation and increased diastolic stiffness, leading to elevated left ventricular end-diastolic pressure despite normal contractile (systolic) function. This causes increased left atrial pressure, pulmonary congestion, and eventually pulmonary hypertension and right heart strain. Common etiologies/risk factors include chronic hypertension (causing concentric LV hypertrophy), obesity, diabetes mellitus, aging, coronary artery disease, and infiltrative diseases (amyloidosis, hemochromatosis, sarcoidosis) and restrictive/hypertrophic cardiomyopathies.

Pathophysiologically, myocardial stiffness increases due to fibrosis, hypertrophy, and altered titin isoform expression, along with impaired calcium handling in relaxation. Systemic inflammation (from comorbidities like obesity and diabetes) contributes to coronary microvascular endothelial dysfunction, a key mechanism per the Paulus-Bauersachs paradigm.

Clinically, patients present with exertional dyspnea, orthopnea, PND, and peripheral edema similar to HFrEF, but with normal EF (≥50%) on echocardiography. Diagnosis requires evidence of diastolic dysfunction: abnormal E/A ratio, elevated E/e' ratio (impaired relaxation), left atrial enlargement, and elevated BNP/NT-proBNP. The H2FPEF score and echocardiographic criteria aid diagnosis.

Management differs from HFrEF: focus is on treating underlying causes (BP control, weight loss, glycemic control) and symptom relief with diuretics for volume overload. SGLT2 inhibitors (e.g., empagliflozin) have shown mortality/hospitalization benefit and are now first-line. Unlike HFrEF, ACE inhibitors, ARBs, and beta-blockers have not shown consistent mortality benefit, though they may be used for comorbid hypertension. Mineralocorticoid receptor antagonists (spironolactone) may have modest benefit.

Board relevance: distinguishing HFpEF from HFrEF via EF and echo findings, recognizing S4 heart sound (from stiff ventricle contracting into non-compliant chamber) versus S3 in HFrEF, and understanding concentric vs eccentric hypertrophy patterns are frequently tested concepts.