[Mitral valve prolapse in the heart with pressure overload of the right ventricle]

The prevalence of mitral valve prolapse (MVP) was examined in 16 patients with right ventricular pressure overload with a peak systolic pressure ranged from 60 to 204 mmHg (Group 1; 9 cases of primary pulmonary hypertension and 7 cases of pulmonary valve stenosis), and the clinical and echocardiographic data were compared to those of 12 patients with idiopathic MVP (Group 2) and 10 healthy persons (Group 3). MVP was defined when either or both of the mitral valve leaflets protruded into the left atrium beyond the plane of the mitral ring, and "gap" was defined as positive when one of the leaflets of the mitral valve slipped 3 mm or more without prolapse toward the left atrium than the other leaflet. Eccentricity of the left ventricle was obtained from the cross-sectional view of the left ventricle at the mid-ventricular level: the ratio of the internal diameter (S) passing through the mid-point of the interventricular septum (IVS) and perpendicular to the IVS divided by the longest internal diameter (L) parallel to the IVS, at end-diastole (S/L(d] and at end-systole (S/L(s], respectively. The following results were obtained. MVP was found in seven cases of 16 patients (43.8%) of Group 1. Two cases had positive "gap" (12.5%). Eccentricity of the left ventricle in Group 1 (S/L(d) 0.81 +/- 0.12, S/L(s) 0.78 +/- 0.15) was more marked than that of Group 2 (S/L(d) 0.98 +/- 0.09, S/L(s) 1.02 +/- 0.06) or of Group 3 (S/L(d) 1.03 +/- 0.08, S/L(s) 1.00 +/- 0.04) (p less than 0.001 in each).(ABSTRACT TRUNCATED AT 250 WORDS)