A 32-year-old woman from rural India presents with progressive dyspnea on exertion and orthopnea for 6 months. On examination, she has a low-volume pulse, a tapping apical impulse, and a loud S1 with an opening snap. A diastolic murmur is heard at the apex. Chest X-ray shows straightening of the left heart border and pulmonary congestion. Which investigation is most appropriate to confirm the diagnosis and assess severity of mitral stenosis?

Explanation

## Investigation of Choice for Mitral Stenosis ### Why Transthoracic Echocardiography with Doppler is Correct **Key Point:** Transthoracic echocardiography (TTE) with Doppler is the gold standard non-invasive investigation for diagnosis and hemodynamic assessment of mitral stenosis. **High-Yield:** TTE provides: - Morphology of mitral valve leaflets (thickening, calcification, commissural fusion) - Mitral valve area (MVA) calculation using planimetry or Doppler pressure half-time method - Mean diastolic pressure gradient across the mitral valve - Assessment of associated lesions (aortic valve disease, left atrial thrombus) - Left atrial and ventricular dimensions - Pulmonary artery pressure estimation ### Severity Grading by Echocardiography | Parameter | Mild MS | Moderate MS | Severe MS | |-----------|---------|-------------|----------| | **MVA (cm²)** | >1.5 | 1.0–1.5 | <1.0 | | **Mean gradient (mmHg)** | <5 | 5–10 | >10 | | **Valve morphology** | Pliable, minimal calcification | Thickened, some calcification | Thick, calcified, restricted leaflets | **Clinical Pearl:** The opening snap heard on auscultation correlates with valve pliability and is absent in calcified, rigid valves—a finding that echocardiography can confirm. ### Why TTE is Superior to Other Modalities - **Non-invasive:** No radiation, no need for catheterization - **Real-time assessment:** Dynamic evaluation during respiration and Valsalva - **Reproducible:** Quantitative measurements of MVA and gradients - **Widely available:** First-line imaging in all centers across India **Mnemonic:** **ECHO** = **E**xact, **C**ost-effective, **H**emodynamic assessment, **O**ptimal first-line [cite:Harrison 21e Ch 298]