Tetralogy of Fallot with subpulmonary ventricular septal defect.

Among a total of 608 patients with tetralogy of Fallot, 35 with tetralogy and subpulmonary ventricular septal defect (VSD) have undergone intracardiac repair at the Children's Hospital, Buenos Aires. The crista supraventricular was absent in 62.9% of these patients; it was hypoplastic in 37.1%. Only 3 patients (8.6%) were severely cyanotic and required operation in infancy. The main and left and right pulmonary arteries were relatively large in all but 1 patient. Nevertheless, patch-graft enlargement across the pulmonary valve ring was necessary in 20 (57.1%). We believe that closure of the subpulmonary VSD increase the apparent severity of the pulmonary stenosis and necessitates patch-graft enlargement in patients in whom the appearance of the right ventricular outflow tract before repair would not have suggested its need.