SPONTANEOUS CLOSURE of ventricular septal defect has beeni suspected oii the basis of elinieal examiinations by physicianis caring for children with congenital cardiae disease. Confiriinative clinieal anid heinodynamic evidence documentinig sponitaneous closure of such lesions also lhave been presented in several recent reports.)-f; In onily one patient, however, has anatomici proof of spontaneous closure of a ventricular septal defeet been recorded.7 We recently studied an adult patient in whom the diagnosis of tricuspid atresia was established and who died after operation. At autopsy, there was unequivocal evidenee that a functional veentricular septal defect had been present and had subsequently closed. The clinical and pathologic observatioirs leading to this conelnion are sumniarized in this report. Clinical Summary A. H. (No. 03-87-02), . 27-vear-old man, had had ovanosis, clubbing, anid a precordial mnurmur since infancy. During childhood and adolescence, fatigue, dyspnea, and repeated upper respiratory infections prevented himni fromrl attending school. At the age of 17 a left subelavia.n-pulmonary arterial anastomosis was perforrned at another hospital. The eyanosis and dyspnea. however, were only transiently inmproved, and his physical activitv beea-ie progressively limited. On examination he was cyanotic, and there was imiarked clubbing of the fingers anld toes. The heart was enlarged, an:d a left ventricular thrust was palpable. The second sound at the base was single, and a -'rade ITIVI ejection-tyvpe systolicmurmur