Early hypercyanotic spells unrelated to ductal constriction in tricuspid atresia with infundibular stenosis.

Clinical, echocardiographic, hemodynamic, and angiographic findings were reviewed in 16 consecutive patients with tricuspid atresia (TA) and normally related great arteries, seen at the University of Florida between 1984 and 1990, to determine when and in which hypercyanotic spells (HS), unrelated to ductal constriction, occurred. Such spells developed in six patients (38%) and were life-threatening and refractory to medical management in three patients. Most HS (five of six) occurred in the first 2 months of life. Angiography done at the time of diagnosis revealed similar morphological features in all patients subsequently experiencing HS; infundibular stenosis due to anterior malalignment in the conal septum. These findings suggest a predisposition for development of early HS in TA patients with apparent infundibular stenosis due to anterior malalignment of the conal septum. Further study and a heightened clinical awareness are needed in such patients.