THE CORONARY CIRCULATION IN COMPLETE TRANSPOSITION OF THE GREAT VESSELS

Long-term follow-up of right ventricular function after Mustard operation for transposition of the great arteries

As development of right ventricular (RV) failure is a potential risk after Mustard operation for transposition of the great arteries, 17 patients were reexamined 5-13 years postoperatively. Comparisons were made with healthy controls. There were no clinical signs of heart failure. Echocardiographically determined RV end-diastolic diameter was increased to 2.5 +/- 0.8 cm (controls: 1.5 +/- 0.4 cm, p less than 0.001). Comparison of RV systolic time intervals (STI) in patients with normal left ventricular (LV) STI revealed decreased RV function, with RPEPI 165 +/- 19 msec (controls 126 +/- 12, p less than 0.001) and RPEP/RVET 0.484 +/- 0.096 (controls 0.284 +/- 0.045, p less than 0.001). Nuclear angiography demonstrated decreased RV ejection fraction (EF), viz. 42.8 +/- 6.6% (normal RV 53 +/- 6%, LV 68 +/- 9%, p less than 0.001). Only two patients showed normal (5%) rise in RV-EF during exercise. There was no evidence of deterioration with passage of time. The results do not justify use of anatomic repair at our center, since the perioperative mortality might then be higher than in the Mustard or Senning procedures.

Early experience with arterial repair of transposition

Major anomalies associated with isolated complete transposition of the great arteries (TGA) can produce systemic pressure in the left ventricle without fixed stenosis of the left ventricular outflow tract. In this situation, arterial repair may be advantageous. Eight children, 10 days to 15 years old, underwent arterial repair of TGA. Major associated anomalies included large patent ductus arteriosus, bulging intraventricular septum, ventricular septal defect (VSD), tricuspid atresia, and the Taussig-Bing type of double-outlet right ventricle. There were 2 operative deaths related to acute left ventricular failure. The survivors underwent postoperative echocardiographic, hemodynamic, and angiographic assessment; all were in sinus rhythm and well six months to 2 1/2 years after operation. Residual lesions have been frequent but mild: aortic insufficiency (5), stenosis of the right ventricular outflow tract (1), trivial VSD (1), and stenosis of the right coronary artery (1). Left ventricular function is "normal" in 4 and unchanged from moderately depressed preoperative status in 1.

Congenitally corrected transposition of the great arteries: morphologic study of 32 cases

The detailed anatomy of the heart is described in 32 autopsy cases of congenitally corrected transposition of the great arteries.Tis condition is defined as the combination of atrioventricular (A-V) discordance and transposition of the great arteries. Examples of primitive (single) ventricle with "inverted" (that is, left-sided in situs solitus) outlet chamber are excluded. Six hearts with A-V discordance and pulmonary atresia are described in an appendix. In 29 cases of corrected transposition the heart was in situs solitus; in 3 it was in situs inversus totalis. Only 5 of these 32 hearts had no potential for intracardiac shunting. Anomalies of the tricuspid valve (91 percent of cases), ventricular septal defect (78 percent) and pulmonary outflow tract obstruction (44 percent) occurred with sufficient frequency to be considered part of the basic malformation and are described in detail. The precise anatomy and disposition of the A-V valve tension apparatus, the coronary arteries and the conducting tissues are described with special reference to possible surgical approaches for repair of the anomalies. In two hearts with situs solitus the aortic valve was right-sided with respect to the pulmonary valve. This finding is important for both diagnosis and nomenclature.