A 72-year-old woman from Mumbai with a 10-year history of hypertension and atrial fibrillation presents with acute dyspnea, orthopnea, and pink frothy sputum. Vital signs: BP 165/100 mmHg, HR 125/min (irregular), RR 32/min, SpO₂ 88% on room air. Chest X-ray shows bilateral alveolar infiltrates. Echocardiography reveals ejection fraction of 50%, left atrial enlargement, and diastolic dysfunction. Serum BNP is 850 pg/mL. What is the most likely diagnosis?

Explanation

## Clinical Presentation Analysis ### Key Diagnostic Features **High-Yield:** This patient presents with **acute decompensated heart failure (ADHF)** with the following supporting evidence: | Feature | Finding | Significance | |---|---|---| | **EF** | 50% (normal) | Preserved EF → HFpEF | | **Diastolic dysfunction** | Present on echo | Hallmark of HFpEF | | **Left atrial enlargement** | Present | Chronic volume overload from diastolic dysfunction | | **BNP** | 850 pg/mL | Elevated (normal <100), confirms HF | | **Acute pulmonary edema** | Pink frothy sputum, bilateral infiltrates | Acute decompensation | | **Precipitant** | Uncontrolled AF (HR 125, irregular) | Loss of atrial kick + RVR → ↑ LV filling pressure | ## Pathophysiology of HFpEF ```mermaid flowchart TD A[Chronic hypertension + AF]:::outcome --> B[Left ventricular stiffness]:::outcome B --> C[Impaired diastolic relaxation]:::outcome C --> D[↑ LV filling pressure]:::outcome D --> E[Atrial enlargement]:::outcome E --> F{Acute AF with RVR}:::decision F -->|Loss of atrial kick| G[Sudden ↑ in LV preload]:::urgent F -->|Tachycardia| H[↓ Diastolic filling time]:::urgent G --> I[Pulmonary edema]:::urgent H --> I ``` **Key Point:** HFpEF accounts for **40–50% of all heart failure cases** in developed countries and is more common in elderly women with hypertension and AF [cite:Harrison 21e Ch 235]. ## Why HFpEF, Not HFrEF? **Clinical Pearl:** The **preserved EF (50%)** is the defining feature. In HFpEF: - Systolic function is normal or hyperdynamic - Problem is **diastolic dysfunction** (impaired relaxation, increased stiffness) - Diagnosis requires: (1) HF symptoms/signs, (2) EF ≥50%, (3) Evidence of diastolic dysfunction (E/e' ratio, LA enlargement, elevated filling pressures) This patient meets all three criteria. ## Precipitants of Acute Decompensation in HFpEF **Mnemonic: CHAMP-FRIED** - **C**oronary ischemia - **H**ypertensive crisis - **A**rrhythmias (AF with RVR) ← **This patient** - **M**itral valve disease - **P**ulmonary embolism - **F**luid overload - **R**enal dysfunction - **I**nfection - **E**ndocrine (thyroid) - **D**rugs (negative inotropes, NSAIDs) In this case, **uncontrolled AF with rapid ventricular response** is the clear precipitant. ## Management of Acute Decompensated HFpEF ### Immediate Steps 1. **Rate control** (priority in AF): - IV digoxin or IV amiodarone - Goal HR <100/min to restore diastolic filling time 2. **Diuresis**: - IV furosemide for pulmonary edema - Target: euvolemia, not aggressive diuresis (HFpEF is preload-sensitive) 3. **Afterload reduction** (if hypertensive): - IV nitroprusside or IV hydralazine - Target: BP <160/100 mmHg 4. **Oxygenation**: - High-flow O₂, CPAP/BiPAP if needed - Goal SpO₂ >90% 5. **Restore sinus rhythm** (if possible): - Consider DC cardioversion if hemodynamically unstable - Amiodarone for rate control + rhythm conversion ### Chronic Management of HFpEF **High-Yield:** Unlike HFrEF, there is **NO mortality benefit** from ACE-I, ARB, or beta-blockers in HFpEF. Management focuses on: - **Rate control in AF** (beta-blockers, calcium channel blockers, digoxin) - **Blood pressure control** (target <130/80 mmHg) - **Diuretics** for symptom relief (not prognostically beneficial) - **Treat comorbidities** (hypertension, AF, diabetes) - **SGLT2 inhibitors** (emerging evidence: empagliflozin, dapagliflozin show symptom benefit) **Warning:** Do NOT use positive inotropes in HFpEF — they worsen diastolic function by increasing contractility and reducing diastolic filling time.