[Mitral valvular disease secondary to mitral ring calcification: a clinicopathologic study].

Fifteen cases with mitral valvular disease caused by mitral ring calcification (MRC) were observed among 2,800 consecutive autopsy patients more than 60 years of age. They consisted of one man and 14 women whose average age was 86.4 years. All had been diagnosed as having mitral valvular disease during life. For this clinicopathologic study, the cases were categorized as nine cases with mitral regurgitation (MR Group) and six with mitral stenosis (MS Group). Among the 15 cases, phonocardiograms were obtained in 14 and echocardiograms in 6. In addition, 122 cases with MRC, the length of which was 5 mm or more, were selected from 900 recent consecutive autopsies of senile patients, to evaluate the site of calcification and to analyze the ratio of calcification length to mitral valve ring circumference. The following conclusions were obtained: The prevalence of mitral valvular disease due to MRC in the aged was 15/2,800 (0.5%). MR was observed in nine cases and MS in six. Phonocardiograms of the MR Group revealed a holosystolic murmur in seven cases, a late systolic murmur in one, a third heart sound in four and a fourth heart sound in five. In the MS Group, a holosystolic murmur was found in four, a presystolic murmur in four, a diastolic rumble in one, but no opening snap in any case. A diamond-shaped systolic murmur was found in nine cases with MS or MR, suggesting an ejection systolic murmur caused by an associated calcified aortic valve. Echocardiograms showed markedly decreased DDR in five cases and increased echo intensity of the aortic valve in four. Pathologic findings revealed that the mean length of MRC was 36.6 mm in the MR Group and 58.0 mm in the MS Group. The calcification ring ratio (CRR = MRC/MVR X 100) was 50.3% in the MR Group and 69.8% in the MS Group. In the MR Group, MRC involved the anterolateral commissure in three, posteromedial commissure in five, and both in one. In five of six cases with MS, both commissures were involved by MRC. The study of 122 cases with MRC length greater than or equal to 5 mm suggested that MRC occurred first in the middle scallop of the posterior mitral leaflet, and extended to the posterior scallop, subsequently extending up to the anterior scallop, and finally involved the anterior mitral leaflet beyond the commissures.(ABSTRACT TRUNCATED AT 400 WORDS)