In the context of coexisting aortic regurgitation with mitral stenosis, evaluation of MS severity is most likely to be which?

In the context of coexisting aortic regurgitation with mitral stenosis, evaluation of MS severity is most likely to be which?

• A. Underestimation
• B. Overestimation
• C. No effect
• D. It remains uncertain

Answer: (A)

The key idea is that the gradient used to gauge mitral stenosis is highly dependent on flow and pressures on both sides of the mitral valve. When a patient also has aortic regurgitation, the left ventricle receives a larger volume (volume overload), which raises the LV end-diastolic pressure. The diastolic transmitral gradient is the difference between left atrial pressure and LV diastolic pressure. If LV diastolic pressure increases, this gradient becomes smaller for the same actual mitral valve area, making the stenosis look less severe than it truly is. So, in this setting, severity assessment based on gradients tends to underestimate the mitral stenosis. In practice, relying on planimetry or other MVA measures less dependent on flow can help avoid this underestimation.

The key idea is that the gradient used to gauge mitral stenosis is highly dependent on flow and pressures on both sides of the mitral valve. When a patient also has aortic regurgitation, the left ventricle receives a larger volume (volume overload), which raises the LV end-diastolic pressure. The diastolic transmitral gradient is the difference between left atrial pressure and LV diastolic pressure. If LV diastolic pressure increases, this gradient becomes smaller for the same actual mitral valve area, making the stenosis look less severe than it truly is. So, in this setting, severity assessment based on gradients tends to underestimate the mitral stenosis. In practice, relying on planimetry or other MVA measures less dependent on flow can help avoid this underestimation.