Conduction defects and mitral annulus calcification.

The incidence of conduction defects in patients with mitral annular calcification was studied in 104 patients and 121 matched controls. The patients comprised 49 men and 55 women, whose ages ranged from 42 to 90 years, with a mean of 70 9 ( SD). The control group consisted of 121 patients without mitral annular calcification, whose ages ranged from 50 to 90 years, with a mean of 68 8 ( SD); there were 61 men and 60 women. Atrial fibrillation with a slow ventricular response, atrioventricular, or fascicular block were found in 73 patients (70%) with mitral annular calcification (37 men and 36 women) compared with 41 patients (34%/) in the control group (24 men and 17 women). Of the 53 patients with isolated calcification of the posterior mitral annulus, 36 (68%) had conduction defects.