Severe MAC causes what functional consequence?

Severe MAC causes what functional consequence?

• A. Functional stenosis because of the fixed thickened annulus
• B. Regurgitation due to annulus dilation
• C. Leaflet prolapse
• D. Obstruction of the LVOT

Answer: (A)

Severe mitral annular calcification makes the mitral annulus rigid and fixed. That lack of flexibility reduces the effective mitral valve area, producing functional mitral stenosis with an elevated transmittal gradient. The valve leaflets may still be normal, but their opening is restricted by the stiff annulus. Regurgitation can occur in some cases when the annulus is calcified and impairs coaptation, but the primary functional consequence of severe MAC is stenosis due to the fixed, thickened annulus. LVOT obstruction is not the typical outcome of MAC unless unusual extension of calcification alters flow near the LVOT, which is not the common mechanism.

Severe mitral annular calcification makes the mitral annulus rigid and fixed. That lack of flexibility reduces the effective mitral valve area, producing functional mitral stenosis with an elevated transmittal gradient. The valve leaflets may still be normal, but their opening is restricted by the stiff annulus. Regurgitation can occur in some cases when the annulus is calcified and impairs coaptation, but the primary functional consequence of severe MAC is stenosis due to the fixed, thickened annulus. LVOT obstruction is not the typical outcome of MAC unless unusual extension of calcification alters flow near the LVOT, which is not the common mechanism.