Anatomic Types and Associated Cardiovascular Abnormalites of the Congenitally Corrected Transposition of the Great Arteries

Chung, Hae Yul

Abstract

Congenitally corrected transposition of the great arteries (TGA) is characterized by atrioventricular and ventriculoarterial discordance. Patients with this lesion usually have complications related to associated cardiac defects, conduction system disturbances, and arrhythmias. The detailed understanding of the pathologic anatomy of the congenitally corrected TGA and its associated cardiac lesions is a desirable prerequisite for successful surgical correction. However, few surveys have been reported it in Korea. A retrospective study was done on the patients diagnosed as a congenitally corrected TGA at the Department of Pediatrics, Chonnam National University Hospital from January 1989 to May 2002. The results were as follows. Congenitally corrected TGA was found in 27 cases of 3,507 patients with congenital heart diseases (0.7%). In the segmental diagnosis, three main anatomic types of congenitally corrected TGA were found: TGA {S,L,L} in 24 of 27 cases (88.9%), one TGA {S,L,D} (3.7%), and 2 cases of TGA {I,D,D} (7.4%). Associated cardiac abnormalities, which were of great clinical and surgical importance, resulted in 13 anatomic subtypes. The most common associated cardiac abnormalities were ventricular septal defect in 23 of 27 cases (85.2%), tricuspid valve abnormalities in 22 cases (81.5%), and pulmonary outflow tract obstruction in 20 cases (74.1%). Tricuspid regurgitation were found in 18 of 27 cases (66.7%), typical Ebstein's anomaly in 3 cases (11.1%), and straddling tricuspid valve in 1 case (3.7%). In conclusion, congenitally corrected TGA is a rare form of congenital heart disease in which morphologically right ventricle functions as the systemic ventricle, and most patients have additional cardiac abnormalities. Due to the complexity of this congenital heart defect, recommendations for therapeutic intervention must be individualized depending on associated cardiac abnormalities and their severity.