A 52-year-old man with a history of rheumatic fever presents with dyspnea and orthopnea. Echocardiography reveals mitral stenosis with an area of 1.2 cm². He is in normal sinus rhythm. What is the drug of choice for symptomatic management?

Explanation

## Mitral Stenosis: Pharmacological Management **Key Point:** In mitral stenosis with normal sinus rhythm, beta-blockers are the first-line agents to control symptoms by reducing heart rate and prolonging diastolic filling time, thereby increasing cardiac output. ### Mechanism of Symptomatic Relief Beta-blockers (e.g., atenolol, metoprolol) work by: 1. **Reducing heart rate** — allows longer diastolic filling across the stenotic mitral valve 2. **Decreasing cardiac contractility** — reduces demand and pulmonary congestion 3. **Improving exercise tolerance** — prevents reflex tachycardia during activity ### Role of Other Agents | Agent | Role in MS | Indication | |-------|-----------|------------| | **Beta-blockers** | First-line, normal SR | Symptom control, rate control | | **Calcium channel blockers** | Alternative if BB contraindicated | Diltiazem/verapamil for rate control | | **Digoxin** | NOT first-line | Only if AF develops (rate + contractility) | | **ACE inhibitors** | No role | Not indicated in isolated MS | | **Diuretics** | Adjunctive | For pulmonary congestion only | **Clinical Pearl:** Diuretics alone without rate control worsen symptoms by increasing heart rate reflexively. Always pair with a rate-limiting agent. **High-Yield:** In mitral stenosis, **avoid vasodilators** (nitrates, ACE-I, hydralazine) — they cause reflex tachycardia and worsen the stenotic lesion by reducing diastolic filling time. ### Definitive Management Once symptomatic MS develops (area < 1.5 cm²), **percutaneous mitral balloon commissurotomy (PMBC)** or **surgical commissurotomy** is the definitive treatment. Medical therapy is a bridge to intervention. **Mnemonic: RATE in MS** — Reduce heart rate, Avoid tachycardia, Treat with beta-blockers, Extend diastolic time.