Effect of atrial septal defect repair on left ventricular geometry and degree of mitral valve prolapse.

To ascertain the effects of surgical closure of atrial septal defect on left ventricular geometry and degree of mitral prolapse, 14 patients with atrial septal defect were studied by cross-sectional and M-mode echocardiography preoperatively and 7 days postoperatively. Seven of the 14 patients (50%) had mitral valve prolapse preoperatively by cross-sectional echocardiography. To quantitate the degree of prolapse, we measured the net algebraic area subtended by the apposed mitral valve leaflets in systole (MVAS) with respect to the mitral ring. The mitral valve prolapse group had an MVAS of 0.3 +/- 3.1 units (mean +/- SEM) preoperatively, while the group without mitral valve prolapse had an MVAS of 12.5 +/- 3.1 units (p less than 0.02). Postoperatively, prolapse either decreased in degree or was abolished in six of seven patients (86%), associated with an increase in MVAS to 14.7 +/- 4.4 units (p less than 0.02). In all patients, septal curvature in diastole on short-axis view normalized either partially or completely postoperatively, resulting in decreased left ventricular eccentricity (1.34 +/- 0.06 preop vs. 1.06 +/- 0.07 postop, p less than 0.001). Atrial septal defect closure, therefore, leads to normalization of left ventricular geometry and in patients with evidence of mitral valve prolapse, is associated with a decrease in the degree of prolapse.