[Conduction disorders and sites of calcification of the mitral ring: 2-dimensional echocardiographic study]

The association between a calcified mitral annulus and impairment of cardiac impulse transmission is well known. However informations on the relations between the site of mitral calcification and conduction disturbance are still scanty. Twenty-nine patients (22 women and 7 men, mean age 64.4 +/- 13.1 years) with M-mode and two-dimensional echocardiographic evidence of mitral annulus calcifications were studied. The "annulus" was subdivided in 4 segments: antero-medial, antero-lateral, postero-medial and postero-lateral. Conduction disturbances were present in 15 patients (51.7%). Atrio-ventricular or intra-ventricular conduction defects were found in 12 out of 15 patients with calcifications of the antero-medial segment and only in 3 of 14 subjects without antero-medial calcifications (P less than .01). The presence of conduction defects therefore seems to be significantly increased when calcium deposition is located near the conduction system.