A 52-year-old woman with a 15-year history of poorly controlled systemic hypertension and type 2 diabetes mellitus presents with progressive fatigue and ankle edema. Her ejection fraction is preserved at 55%, but she has elevated left ventricular end-diastolic pressure on catheterization. What is the most common cause of diastolic heart failure in this patient?

Explanation

## Most Common Cause of Diastolic Heart Failure: Hypertension ### Definition and Epidemiology **Key Point:** Diastolic heart failure (HFpEF — heart failure with preserved ejection fraction) accounts for 40–50% of all HF cases, and hypertension is the single most common cause, responsible for approximately 70–80% of diastolic HF cases. **High-Yield:** HFpEF is increasingly prevalent in older patients, women, and those with hypertension and/or diabetes. Hypertension causes diastolic dysfunction through LVH and myocardial fibrosis long before systolic function declines. ### Pathophysiology of Hypertensive Diastolic Dysfunction 1. **Chronic pressure overload** → left ventricular hypertrophy 2. **Increased myocardial stiffness** → impaired relaxation 3. **Myocardial fibrosis** → reduced compliance 4. **Elevated filling pressures** → pulmonary and systemic congestion 5. **Preserved systolic function** (EF ≥50%) despite diastolic impairment ### Clinical Features in This Patient - Long-standing hypertension (15 years, poorly controlled) - Type 2 diabetes (additional risk for diastolic dysfunction) - Preserved ejection fraction (55%) - Elevated LVEDP on catheterization (hallmark of diastolic dysfunction) - Congestion symptoms (fatigue, ankle edema) This constellation is diagnostic of hypertensive diastolic heart failure. ### Causes of Diastolic Heart Failure: Comparative Table | Cause | Frequency in HFpEF (%) | Mechanism | Key Diagnostic Feature | |-------|------------------------|-----------|------------------------| | Hypertension | 70–80 | LVH, fibrosis, impaired relaxation | LVH on echo; long HTN history | | Mitral stenosis | 5–10 | Mechanical obstruction to LV filling | Diastolic murmur; stenotic mitral valve on echo | | Restrictive cardiomyopathy | 2–5 | Myocardial infiltration; severe stiffness | Restrictive filling pattern; specific etiology (amyloid, sarcoid) | | Constrictive pericarditis | 2–5 | Pericardial thickening; external compression | Pericardial thickening on imaging; "square root sign" on catheterization | **Mnemonic for HFpEF causes: CHAMP** — **C**oronary disease, **H**ypertension, **A**ging, **M**itral stenosis, **P**ericardial disease. Hypertension dominates this list. ### Why Hypertension Is the Answer In the context of: - Decades-long hypertension - Preserved systolic function - Elevated filling pressures - No mention of mitral stenosis (no murmur, no valve pathology) - No mention of infiltrative disease or pericardial pathology Hypertension is overwhelmingly the most likely cause of diastolic HF. **Clinical Pearl:** The combination of hypertension + diabetes significantly accelerates diastolic dysfunction through both pressure overload and metabolic effects on the myocardium.