Mitral annular calcification: clinical and echocardiographic features.

One hundred records from patients with the single or two-dimensional echocardiographic (2DE) diagnosis of mitral annular calcification (MAC) were analyzed. 2DE manifestations of MAC included a characteristic bright structure located at the junction of the A-V groove and posterior mitral leaflet. Sixteen of the 100 patients had idiopathic hypertrophic subaortic stenosis (IHSS), a 44% (16/36) incidence in all patients with IHSS having echoes during the study period. IHSS patients with MAC were significantly older (mean 61 years vs. 43 years, p < .005) than 20 other IHSS patients without MAC studied during the same period. Both IHSS patients and non-IHSS patients with MAC had significantly lower serum calcium levels than normals or the IHSS patients without MAC. These observations support the view that the pathogenesis of MAC is related to degenerative changes from aging and increased stress on the mitral apparatus. Alterations in calcium metabolism possibly contribute to calcium deposition in the mitral annulus.