Mitral Valve Area
Choose the preferred method based on available echocardiographic measurements. Pressure half-time is quick; continuity equation may be more accurate in certain scenarios.
Measure from deceleration slope of mitral inflow E-wave.
How to Use This Calculator
Select the method
Pressure half-time is often used post-TTE. Continuity equation requires accurate LVOT measurements and Doppler alignment.
Enter echocardiographic data
Ensure measurements are averaged over 3–5 beats (more in AF) and obtained with optimal Doppler signal quality.
Correlate with clinical findings
Combine valve area with gradients, symptoms, pulmonary pressures, and planimetry to grade mitral stenosis severity.
Formula
Pressure half-time: MVA (cm²) = 220 ÷ PHT (ms)
Continuity equation: MVA (cm²) = (LVOT area × LVOT VTI) ÷ Mitral inflow VTI
LVOT area = π × (LVOT diameter ÷ 2)²
Full Description
Mitral valve area quantifies obstruction severity in rheumatic or degenerative mitral stenosis. Pressure half-time relies on the decay of transmitral flow and may be unreliable after percutaneous valvotomy or in altered chamber compliance. The continuity equation uses LV stroke volume and mitral inflow to calculate area, benefiting from high-quality Doppler data. Planimetry via 3D TEE or cardiac MRI can provide reference measurements when Doppler methods are inconclusive.
Frequently Asked Questions
When should I prefer continuity equation?
Use when pressure half-time is unreliable, such as post-balloon valvotomy, in significant AR, or when LV/LA compliance is abnormal.
Can I average multiple methods?
Yes. Correlate continuity, planimetry, and PHT results; discrepant values warrant re-evaluation of measurements and hemodynamics.
What are typical severe MS values?
Severe mitral stenosis: MVA ≤1.0 cm² and mean gradient ≥10 mmHg at normal heart rate.
How does heart rate affect results?
Tachycardia shortens diastole and may overestimate gradients; average measurements and consider rate control for accurate assessment.