Comparison of mitral valve dimensions in adults with valvular aortic stenosis, pure aortic regurgitation and hypertrophic cardiomyopathy.

To assess the effect of left ventricular dilatation on mitral valve size, this study compared the dimensions of the mitral valve in patients with aortic valve disease and hypertrophic cardiomyopathy (HC). A total of 216 valves, removed at operation or necropsy, was analyzed by quantitative morphometric methods from: (1) 2 patient groups with dilated left ventricular cavities (i.e., 17 patients with dilated valvular aortic stenosis [AS] and 31 with pure aortic regurgitation), (2) 2 patient groups without dilated left ventricular cavities (i.e., 29 patients with nondilated AS and 94 with HC), and (3) 45 control subjects without heart disease. Mean mitral leaflet areas in patients with AS with dilated left ventricular cavities (13.1 +/- 3.0 cm2) and aortic regurgitation (12.0 +/- 3.6 cm2) were significantly greater than in control subjects (8.7 +/- 2.0 cm2; p < 0.001). Mean mitral leaflet areas in patients with AS without dilated left ventricular cavities (9.8 +/- 2.0 cm2) were similar to those of normal valves (p = NS). However, mean mitral leaflet area in patients with HC, in whom left ventricular cavities were also nondilated, was significantly greater (12.8 +/- 3.7 cm2) than in those with nondilated AS and in normal subjects (p < 0.001). Therefore, increased mitral leaflet area: (1) is often present in patients with aortic valve disease with dilated left ventricles in whom it appears to be secondary to left ventricular chamber dilatation; and (2) cannot be attributed to left ventricular cavity dilatation in patients with HC, since their cavities were of normal or small size.(ABSTRACT TRUNCATED AT 250 WORDS)