[Mitral valve prolapse in patients with post-operative atrial septal defect: a preliminary report].

To investigate the clinical significance of mitral valve prolapse (MVP) in patients with atrial septal defect, we investigated 90 patients using various techniques including phonocardiography, mechanocardiography and echocardiography. The examinations were repeated pre- and post-operative periods, and the particular attention was paid on the behavior of the mitral valve motion after surgery. Post-operatively, the incidence of MVP was 56% (50 of 90 patients) compared with the preoperative incidence of 78%. Improvement of MVP was only 24%, and there was no case in which MVP newly developed after surgery. Clinical and laboratory data indicated that the cases with MVP after surgery had larger Qp/Qs, higher pulmonary pressures and larger right ventricular dimension pre-operatively, but had no relationship to the age of surgery and the deformity index of the left ventricle. MVP after surgery was not associated with significant mitral regurgitation.