Left ventricular function in tricuspid atresia: a radionuclide study

Left ventricular function was evaluated by radionuclide angiocardiography in patients with tricuspid atresia before and after the Fontan operation. Ejection fraction was 0.54 +/- 0.13 in 29 patients without the Fontan procedure and 0.56 +/- 0.14 in 14 postoperative patients. Group means were not statistically different, but both were less than normal values for the institution (p less than 0.001). Function did not correlate significantly with age or aortic oxygen saturation. Serial studies demonstrated little change in eight of nine patients examined over 1 to 3 years preoperatively. From the preoperative group of nine patients with abnormal ejection fraction, three underwent surgery, with two survivors. Although 5 of 14 patients had abnormal systolic function after the Fontan operation, only 1 was symptomatic. Depressed response to isometric exercise was found in two patients with a normal ejection fraction at rest. Group systolic function after Fontan surgery did not correlate significantly with age at surgery but all patients were operated on at more than 5 years of age. Of seven patients studied both preoperatively and postoperatively two had an increase and three a decrease in ejection fraction. The trend in these seven studied serially after surgery was toward early improvement in ejection fraction. This study shows variability in left ventricular performance in patients with tricuspid atresia before and after surgery. Individuals undergoing the Fontan procedure after 5 years of age do not necessarily have an increase in ejection fraction over preoperative values, and may even have a decrease. Serial improvement over early postoperative results may be expected, without significant deterioration, during the next 1 to 3 years.