Hypertensive pulmonary vascular disease in alpha-transposition of the great arteries.

In subjects with classic complete transposition (d-transposition) of the great arteries, the pulmonary arterial plexiform lesion, characteristic of chronic high levels of pulmonary arterial pressure, was observed in those with an intact ventricular septum as well as in those with a ventricular septal defect. The lesion was not observed before age 12 months. Among 16 patients aged 12 to 30 months, the plexiform lesion was observed in 6 of 12 patients (50 percent) with an intact ventricular septum and a closed ductus arteriosus and in 1 of 4 patinets with an associated ventricular septal defect. The basis of the plexiform lesion, which is considered a sign of chronic severe pulmonary hypertension, occurring in subjects with an intact ventricular septum and a closed ductus arteriosus is not explained. The phenomenon observed in this study confirms the earlier observations of others.