Radionuclide angiographic evaluation of right and left ventricular function during exercise after repair of transposition of the great arteries. Comparison with normal subjects and patients with congenitally corrected transposition.

We assessed the incidence, clinical significance and etiology of ventricular dysfunction after intraatrial repair of d-transposition of the great arteries in 11 patients, mean age 9 +/- 3 years, who had had Mustard operations. We compared the results to 15 patients who were considered to have normal ventricular function, two patients who had Rastelli operations and five patients with congenitally corrected transposition. Gated equilibrium radionuclide angiography with supine exercise stress testing was used to assess these children. We found no significant difference between our patient groups in exercise capacity, heart rate, or blood pressure response to exercise. However, we found a high incidence of right ventricular dysfunction in the patient groups, manifested by an abnormal right ventricular ejection fraction response to dysfunction in the patient groups, manifested by an abnormal right ventricular ejection fraction response to exercise in six of 11 patients with a Mustard repair, both patients with a Rastelli repair and all five with congenitally corrected transposition. In addition, the left ventricular response to exercise was abnormal in 10 of 11 patients who had undergone a Mustard repair, both patients with a Rastelli repair, and two of five patients with congenitally corrected transposition. We conclude that biventricular dysfunction is frequently present after intraatrial repair of d-transposition of the great arteries. Despite this dysfunction, no significant decrease in exercise tolerance is found in childhood.