Conduction defects and mitral annulus calcification.

Abstract

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 42-90 yr, with a mean of 70 .+-. 9 (.+-. SD). The control group consisted of 121 patients, 61 men and 60 women, without mitral annular calcification, whose ages ranged from 50-90 yr, with a mean of 68 .+-. 8 (.+-. SD). Atrial fibrillation with a slow ventricular response, atroiventricular 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. Anterior and posterior mitral annular calcification were present in 43 patients; 29 (67%) had conduction defects. Sixty-eight patients had mitral annular calcification and aortic calcification; 49 (72%) had conduction defects. In the control group, 20 patients had aortic calcification; 7 (35%) had conduction defects. A significantly increased incidence of conduction defects is present in patients with mitral annular calcification when compared with controls. This is uninfluenced by sex. The incidence of conduction defects with posterior mitral annular calcification is similar to that found with combined anterior and posterior mitral annular calcification. Aortic calcification, alone or with mitral annular calcification, is not associated with an increase in the incidence of conduction defects.