Echocardiographic Assessment of Mitral Stenosis

Primary Severity Parameters

The American College of Cardiology recommends that mitral valve area (MVA) measured by 2D planimetry is the most direct and reliable parameter for grading mitral stenosis severity, with severe stenosis defined as MVA < 1.0 cm², moderate as 1.0-1.5 cm², and mild as > 1.5 cm² 1
Severe mitral stenosis is defined as a mean transmitral gradient > 10 mmHg at rest, moderate stenosis as 5-10 mmHg, and mild stenosis as < 5 mmHg, as measured using continuous wave Doppler across the mitral valve 1
The European Society of Cardiology recommends measuring the mean gradient using continuous wave Doppler across the mitral valve, ensuring maximal sweep speed and minimal velocity scale for optimal accuracy 2
Pulmonary Artery Systolic Pressure (PASP) reflects the hemodynamic consequences of mitral stenosis and provides prognostic information beyond valve area alone, with severe stenosis defined as > 50 mmHg at rest, moderate as 30-50 mmHg, and mild as < 30 mmHg 1

The European Heart Journal recommends exercise echocardiography when resting hemodynamics do not match clinical symptoms, specifically in asymptomatic patients with severe mitral stenosis (MVA < 1 cm²) or symptomatic patients with non-severe mitral stenosis (MVA > 1.5 cm²) 2, 1
During stress testing, hemodynamically significant mitral stenosis is defined by a mean gradient > 15 mmHg during exercise, > 18 mmHg during dobutamine infusion, or PASP > 60 mmHg during exercise 2, 1

The American College of Radiology recommends TEE when TTE images are suboptimal or technically inadequate, excluding left atrial thrombus before percutaneous mitral commissurotomy, assessing valve suitability for percutaneous intervention, or when clinical findings are discordant with TTE results 3, 1

The American College of Cardiology recommends integrating clinical examination with echocardiographic findings, as a high pre-test probability from physical examination should prompt additional investigation if echo results are discordant 4
The Journal of the American College of Cardiology recommends considering concomitant valve disease, body size, atrial fibrillation, and low flow states when evaluating mitral stenosis severity 1, 2, 4, 5