Which gradient measure is used to assess MS severity, particularly for severe MS?

• A. Ejection fraction
• B. Pulmonary artery pressure
• C. Right atrial pressure
• D. Mean gradient

Answer: (D)

Mitral stenosis severity is driven by how hard the blood has to flow through the narrowed mitral valve during diastole. The mean transmitral gradient captures that obstruction by measuring the average pressure difference between the left atrium and left ventricle throughout diastole. As the valve area narrows, this gradient rises, making it a reliable indicator of how severe the stenosis is, especially for identifying severe cases. Ejection fraction looks at systolic function and isn’t a measure of mitral valve obstruction. Pulmonary artery pressure can rise due to downstream effects of MS but doesn’t quantify the stenosis itself. Right atrial pressure reflects preload and isn’t used to grade MS severity. So the mean gradient across the mitral valve is the best measure for assessing MS severity, particularly when MS is severe.