8 Key Points in assessment of Rheumatic Mitral Stenosis

Rheumatic Mitral Stenosis – Key Echocardiographic Assessment Points

1) Morphologic Features (2D Echo – Parasternal & Apical Views)

• Thickened mitral leaflets (especially leaflet tips)

• Diastolic doming of anterior leaflet (“hockey stick” appearance)

• Commissural fusion (best seen in parasternal short axis)

• Reduced leaflet mobility

• Subvalvular involvement: chordal thickening, fusion, shortening

• Calcification (late disease)

Rheumatic MS typically shows leaflet tip restriction with relatively preserved basal leaflet mobility (early disease).

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2) Mitral Valve Area (MVA) – Severity Assessment

• Planimetry (PSAX at leaflet tips in mid-diastole) – Gold standard if image quality good

• Pressure Half-Time (PHT method):

MVA = 220 / PHT

• Continuity equation (if significant MR absent)

Severity grading:

• Mild: MVA > 1.5 cm²

• Moderate: 1.0–1.5 cm²

• Severe: < 1.0 cm²

• Very severe: ≤ 0.8 cm²

Always prefer planimetry when feasible.

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3) Transmitral Doppler Assessment

• Mean transmitral gradient (CW Doppler, apical 4 chamber)

Mild: < 5 mmHg

Moderate: 5–10 mmHg

Severe: > 10 mmHg (at normal HR)

Interpret gradient with:

• Heart rate

• Cardiac output

• Rhythm (AF increases variability)

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4) Left Atrium (LA) Assessment

• LA enlargement (common and often marked)

• Spontaneous echo contrast (“smoke”)

• LA appendage thrombus (best on TEE)

LA size correlates with chronicity and AF risk.

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5) Pulmonary Hypertension

• Estimate RVSP from TR jet

• Secondary PH common in moderate–severe MS

• RV enlargement and dysfunction in advanced disease

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6) Associated Valve Lesions

• Mitral regurgitation (often mild–moderate)

• Aortic valve involvement (rheumatic multivalvular disease)

• Tricuspid regurgitation secondary to PH

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7) Wilkins Score (Balloon Valvotomy Suitability)

Four components (1–4 each):

• Leaflet mobility

• Leaflet thickening

• Calcification

• Subvalvular thickening

Total score ≤ 8 → favorable for PTMC

Score > 10 → less favorable outcome

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8) Important Pitfalls

• Tachycardia overestimates gradient

• AF → average 5–10 beats

• Significant MR → PHT unreliable

• Severe LA compliance changes affect Doppler interpretation

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Practical Structured Reporting Template

1. Morphology consistent with rheumatic disease (yes/no)

2. MVA (planimetry + PHT)

3. Mean gradient at HR ___ bpm

4. LA size and thrombus status

5. PASP/RVSP

6. MR/TR severity

7. Wilkins score