A 38-year-old woman from Mumbai with a history of acute rheumatic fever at age 8 presents with progressive dyspnea and palpitations over 2 months. On examination, she has an opening snap and a low-pitched diastolic rumble at the apex, with an irregular pulse (rate 110/min). ECG shows atrial fibrillation. Transthoracic echocardiography reveals mitral stenosis with a valve area of 1.2 cm² and moderate left atrial enlargement. Left ventricular ejection fraction is 55%. There is no evidence of thrombus on transesophageal echocardiography. What is the most appropriate next step in management?

Explanation

## Clinical Assessment **Key Point:** Symptomatic mitral stenosis with moderate-to-severe stenosis (valve area 1.2 cm²) and new-onset atrial fibrillation is an indication for percutaneous mitral balloon valvuloplasty (PMBV) if anatomy is favorable. ### Severity Grading of Mitral Stenosis | MVA (cm²) | Severity | Hemodynamics | |-----------|----------|---------------| | >2.5 | Mild | Minimal obstruction | | 1.5–2.5 | Moderate | Moderate gradient | | 1.0–1.5 | Moderate-severe | Significant obstruction | | <1.0 | Severe | Critical stenosis | **High-Yield:** This patient's MVA of 1.2 cm² = moderate-severe stenosis with clear hemodynamic significance. ### Indications for PMBV [cite:Harrison 21e Ch 297] **Class I (Symptomatic patients with favorable anatomy):** - Symptomatic MS (NYHA II–IV) + MVA ≤1.5 cm² + no left atrial thrombus + no moderate/severe MR **Class IIa (Selected asymptomatic patients):** - Asymptomatic MS + MVA ≤1.5 cm² + high thromboembolic risk (AF, prior stroke) ### Why PMBV Is the Best Next Step Here 1. **Symptomatic** (dyspnea, palpitations) ✓ 2. **Severe enough** (MVA 1.2 cm²) ✓ 3. **Favorable anatomy** (no thrombus on TEE, no mention of severe MR or calcification) ✓ 4. **New AF** = high thromboembolic risk → urgent intervention indicated **Clinical Pearl:** PMBV is the preferred first-line intervention in rheumatic MS with suitable valve anatomy because it: - Avoids surgical morbidity - Preserves native valve - Can be repeated if needed - Immediate symptom relief ### Management Algorithm for Symptomatic MS ```mermaid flowchart TD A["Symptomatic MS"]:::outcome --> B{"MVA ≤1.5 cm²?"}:::decision B -->|"No"| C["Medical management only"]:::action B -->|"Yes"| D{"Favorable anatomy?"}:::decision D -->|"No (calcified, MR, thrombus)"| E["Mitral valve replacement"]:::action D -->|"Yes"| F["PMBV"]:::action A --> G["Anticoagulation (AF present)"]:::action A --> H["Rate control"]:::action ``` **Mnemonic:** **PMBV FIRST** = **P**ercutaneous **M**itral **B**alloon **V**alvuloplasty in **F**avorable anatomy, **I**ndicated for **R**heumatic **S**tenosis, **T**herapy-responsive. **Warning:** Do NOT confuse PMBV with mitral valve replacement. PMBV is first-line for favorable anatomy; MVR is reserved for unfavorable anatomy (heavy calcification, severe MR, thrombus, failed PMBV).