Transposition of the great vessels anatomy


 * Associate Editor(s)-In-Chief: Priyamvada Singh, M.B.B.S. [mailto:psingh@perfuse.org]; ; Keri Shafer, M.D. [mailto:kshafer@bidmc.harvard.edu]; Assistant Editor(s)-In-Chief: Kristin Feeney, B.S. [mailto:kfeeney@perfuse.org]

Anatomy


Normal Heart
 * Normally, the morphologic right atrium (RA) is connected to a morphologic right ventricle (RV). The morphologic left atrium (LA) is connected to the morphologic left ventricle (LV). This is called atrio-ventricular concordance.
 * In a normal heart, the great arteries (aorta and pulmonary arteries) are concordant with the morphologic LV and RV. This is termed ventriculo-arterial concordance.
 * In addition, the aorta and pulmonary trunk ascend in a spiral relationship.

Transposition of the great vessels
 * In the TGA the aorta arises from the morphologic right ventricle via a subaortic infundibulum and the pulmonary artery arises from the morphologic left ventricle, without a subpulmonary infundibulum. These ventriculoarterial connection is known as ventriculoarterial discordance. As a consequence, there is a a fibrous continuity between the mitral and pulmonary valve, but no continuity between the tricuspid and aortic valve.
 * The abnormal origin of the great arteries results in an altered spiral relationship. Therefore, the aorta and pulmonary artery run parallel to each other
 * In normal heart thus the circulation is in series. However, in transposition of the great vessels circulation is in parallel

dextro-Transposition of the great vessels
 * d-TGA is also referred to as complete or uncorrected transposition of the great arteries identifying the single discordance between ventricles and great arteries

levo-Transposition of the great vessels
 * l-TGA is referred to as congenitally corrected transposition, identifying a double discordance (atrioventricular and ventriculoarterial).