The pulmonary vascular bed in patients with complete transposition of the great arteries.

Histological material obtained at autopsy from 35 patients over three months of age with complete transposition of the great arteries (TGA) was examined. Two of six patients less than a year of age with an intact ventricular septum and closed ductus arteriosus were found to have pulmonary vascular changes of at least grade 3 severity; in addition, two of seven patients with a large ventricular septal defect in this age group showed changes of similar severity. The reported low incidence of marked pulmonary vascular changes in patients with only an interatrial communication dying during the first year of life would appear to be due in part to the high proportion of cases less than three months old in whom there was not sufficient time for such changes to develop. Although the incidence is not as high as that found beyond a year of age, it is sufficiently high to influence the management of infants beyond three months of age. Hemodynamic studies were performed following atrial baffle repair in 34 patients. ...