[Long-term results of Mustard operation in transposition of the great arteries. Angiographic and nuclear medicine study of ventricular function].

The fate of the right ventricle as systemic ventricle after atrial repair of complete transposition of the great arteries has not been clearly elucidated. In order to assess the long-term results of the Mustard operation in patients with complete transposition of the great arteries we present the clinical data of 23 patients who had been operated in the years 1974 and 1975. Twenty of these patients had simple complete transposition of the great arteries with intact ventricular septum, two had an additional small ventricular septal defect and one an additional left ventricular outflow tract obstruction with a 40 mm Hg systolic pressure gradient. The Mustard operation had been performed at a mean age of 2.2 (1 to 3.7) years. Seventeen of the 23 patients underwent a postoperative hemodynamic study with angiocardiography 1.1 (1 to 1.8) years following surgery. At that time the right ventricular ejection fraction, which had been calculated from biplane angiographic right ventricular volume measurements in twelve patients was 62 (52 to 68) %. However the right ventricle was dilated and the mean enddiastolic volume was 132 (108 to 192) % of normal. In twelve of the 23 patients right ventricular function was reassessed 12.6 (11 to 15.3) years after surgery by Technetium-99m-scintigraphy at rest and in ten of those after exercise with a workload of 2 watt/kg. The mean ejection fraction was 51 (38 to 66) % at rest and 52 (40 to 80) % during exercise. Only three patients had a normal response to exercise, which was defined as an increase of ejection fraction with exercise of more than 5%.(ABSTRACT TRUNCATED AT 250 WORDS)