A 48-year-old man from Delhi with a known history of mitral stenosis (MVA 1.0 cm²) presents to the emergency department with acute onset palpitations and dyspnea. On examination, he is tachycardic (heart rate 138/min) with an irregular pulse. Blood pressure is 128/82 mmHg. Auscultation reveals an irregular rhythm with variable S1 intensity and loss of the opening snap. Chest X-ray shows acute pulmonary edema. ECG shows atrial fibrillation with rapid ventricular response. Troponin is negative. What is the immediate management priority?

Explanation

## Acute Presentation: AF with RVR in MS **Key Point:** Atrial fibrillation with rapid ventricular response (AF with RVR) is a **medical emergency** in mitral stenosis because the loss of atrial kick and shortened diastolic filling time critically reduce cardiac output in a fixed stenotic orifice. ## Pathophysiology ```mermaid flowchart TD A["Mitral Stenosis<br/>Fixed MVA = 1.0 cm²"]:::outcome --> B["Atrial Fibrillation"]:::urgent B --> C["Loss of atrial kick"]:::urgent B --> D["Shortened diastole"]:::urgent C --> E["↓ Cardiac output"]:::urgent D --> E E --> F["Acute pulmonary edema<br/>Hemodynamic collapse"]:::urgent ``` ## Immediate Management Algorithm ```mermaid flowchart TD A["AF with RVR + MS<br/>+ Pulmonary edema"]:::outcome --> B{"Hemodynamically<br/>unstable?"}:::decision B -->|"Yes<br/>SBP < 90 or shock"|C["Urgent cardioversion"]:::urgent B -->|"No<br/>SBP > 100"|D["Rate control first"]:::action C --> E["IV heparin"]:::action D --> E E --> F["IV digoxin or<br/>IV beta-blocker"]:::action F --> G["Diuretics for pulmonary edema"]:::action G --> H["Anticoagulation<br/>long-term"]:::action ``` ## Immediate Management Priorities 1. **Anticoagulation** — IV heparin (unfractionated or LMWH) to prevent thromboembolism (high risk in AF + MS). 2. **Rate control** — IV digoxin (preferred in acute HF) or IV beta-blocker/calcium channel blocker to slow ventricular response and restore diastolic filling time. 3. **Diuretics** — IV furosemide for acute pulmonary edema. 4. **Cardioversion** — Consider if hemodynamically unstable (SBP <90, altered mental status, cardiogenic shock) or if rate control fails. **High-Yield:** Digoxin is preferred over beta-blockers in acute MS with AF because it provides both rate control AND positive inotropy, improving cardiac output in the setting of reduced diastolic filling. **Warning:** Do NOT delay rate control or anticoagulation while arranging PTMC or surgery. Medical stabilization is the immediate priority. **Clinical Pearl:** The loss of the opening snap on auscultation in this patient reflects the irregular rhythm and variable diastolic filling times; it does not indicate valve rupture or acute worsening of stenosis severity. **Mnemonic: Acute AF + MS Management — HERD** - **H**eparin (anticoagulation) - **E**lectrolytes and diuretics (pulmonary edema) - **R**ate control (digoxin/beta-blocker) - **D**efinitive therapy (cardioversion if unstable; PTMC/surgery after stabilization)