Spontaneous closure of physiologically advantageous ventricular septal defects.

murmur of decreasing intensity. His ventricular septal defect, previously demonstrated angiocardiographically, could not be found at autopsy; it is presumed to have closed by fusion of its muscular rims with subsequent covering by endocardial proliferation. The second patient, with a double-outlet right ventricle, demonstrated progressive left ventricular enlargement and congestive failure despite increasing pulmonary vascular resistance. Postmortem examination showed that this defect