Functional mitral stenosis in patients with massive mitral annular calcification.

Mitral insufficiency with mitral annular calcification occurring predominantly in elderly females has been described. We studied six patients with mitral diastolic obstruction associated with mitral annular calcification without stenosis of the mitral leaflets. Three were males and three were females, aged 43-77 years. All had significant diastolic gradients across the mitral valve (mean gradient 16 mm Hg) recorded at catheterization. Two patients had aortic and three had mitral valve replacement. No patient had retraction of the mitral leaflets, diffuse thickening or fusion of the commissures at surgery or pathologic examination. Three patients had severe mitral insufficiency, one associated with voluminous prolapsing mitral leaflets and one as a result of ruptured chordae tendineae. The left ventricle was dilated in three patients, two with mitral regurgitation and one with mixed aortic valve disease. Active mitral annular motion is a normal event and is necessary for normal valvular function; severe calcification of the ring interferes with its normal diastolic relaxation and this alone may explain the holodiastolic mitral gradient found in these patients.