Prolapsing mitral valve leaflet syndrome. A spectrum that includes cleft posterior mitral valve.

Two patients with a prolapse and cleft posterior mitral leaflet were studied. The first case had an associated ostium secundum type atrial septal defect. In both cases, the pansystolic regurgitation of contrast material during angiography corresponded to the pansystolic configuration of the murmur. In each instance, the systolic murmurs displayed a late systolic accentuation during the maximal prolapse of the mitral valve. The echocardiographic studies demonstrated only a late systolic prolapse which in both patients corresponded angiocardiographically to the maximum buckling of the pansystolic prolapse. Echocardiographic and angiocardiographic features of cleft posterior mitral valve leaflet are discussed.