Right ventricular volume determinations in 18 patients with pulmonary atresia and intact ventricular septum. Analysis of factors influencing right ventricular growth.

Right ventricular growth was assessed angiocardiographically in 18 patients with pulmonary atresia, intact ventricular septum, and hypoplastic and hypertensive right ventricle. A variety of surgical procedures were performed. In only 12 patients (66.7%) was right ventricular-pulmonary artery continuity achieved (group 1). Nine of these 12 patients persisted with systemic or suprasystemic right ventricular pressures. Among the six patients in whom right ventricular-pulmonary artery continuity was not achieved (group 2), all maintained suprasystemic right ventricular pressures. Right ventricular growth was assessed in groups 1 and 2. The patients were also subdivided according to the qualitative degree of tricuspid regurgitation as determined angiocardiographically on right ventricular cineangiocardiograms at the preoperative catheter study. Right ventricular growth to normal levels as evidenced by change in right ventricular end-diastolic volume was rarely observed in group 2 patients. Among the four patients with severe tricuspid regurgitation and a large tricuspid valve, right ventricular growth to normal levels was achieved whether they were in group 1 or group 2. Right ventricular growth is thus predicated on numerous morphologic factors in these patients. However, reconstitution of right ventricular-pulmonary artery continuity and a nonobstructive tricuspid valve are probably two of the more important factors.