Transesophageal echocardiographic evaluation of mitral regurgitation in hypertrophic cardiomyopathy: contributions of eccentric left ventricular hypertrophy and related abnormalities of the mitral complex.

This study was designed to evaluate the contribution of eccentric left ventricular hypertrophy and its related organic and spatial abnormalities of the mitral complex to the occurrence of mitral regurgitation in patients with hypertrophic cardiomyopathy We selected 45 consecutive patients with systolic mitral regurgitation by color Doppler echocardiography and performed transesophageal echocardiography in all patients. Eighteen patients were in the obstructive group and 27 patients were in the nonobstructive group of hypertrophic cardiomyopathy with asymmetric septal hypertrophy. Twenty subjects without any cardiac disorders served as the control group. The maximum area of mitral regurgitation was significantly greater in the obstructive group than in the nonobstructive group. Mitral regurgitation appeared more frequently during pansystole in the two groups with hypertrophic cardiomyopathy, particularly in the obstructive group. Mitral valve prolapse was observed in 20 (44%) of the 45 patients with hypertrophic cardiomyopathy. Distances between the posterior papillary muscle and anterior or posterior mitral anulus were significantly smaller in the two groups with hypertrophic cardiomyopathy than in the normal control group. In the obstructive group, the length of the anterior mitral leaflet and the thickness of the rough zone of the anterior mitral leaflet at mid-diastole were significantly greater than in the other groups. Systolic anterior motion was observed in all patients with obstructive cardiomyopathy and contact between the interventricular septum and the anterior mitral leaflet during early diastole was observed in 17 of the 18 patients in the obstructive group.(ABSTRACT TRUNCATED AT 250 WORDS)