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.