Simple D-Transposition of the great arteries (TGA) with ventricular septal defect (VSD) and pulmonary valve stenosis (PS)

Transposition is the condition in which the great arteries take origin from the ventricles in reverse position across (“trans”) the ventricular septum: the aorta from the right ventricle and the pulmonary trunk from the left ventricle (1). In terms of segmental sequence, this corresponds to discordant ventriculo-arterial (VA) connection (2–5).

Complete transposition of the great arteries (TGA) identifies an anatomical complex in the setting of a defined situs (solitus or inversus), in which the right atrium is connected with the right ventricle from which the aorta takes origin and the left atrium is connected with the left ventricle from which the pulmonary artery takes origin [concordant atrioventricular (AV) and discordant VA connections] (2–10). Different anatomical complexes of complete TGA can be identified according to the presence of intact ventricular septum, ventricular septal defect (VSD), or obstructions to the right or left ventricular outflow.

However, among congenital heart disease (CHD), there are other malformations in which discordant VA connections are present. In situs solitus or inversus, discordant VA connection can be found in association with discordant AV connection (so-called “congenitally corrected transposition”) (11–13) or in presence of univentricular connection (absent or double inlet connection) (14). Moreover, discordant VA connections are also present in hearts with right or left isomerism (15) with biventricular or univentricular AV connections (14).

Our aim was to identify, by reviewing the hearts of the Anatomical Collection of CHD of the University of Padua, all the cases with discordant VA connection for a description of the anatomical variants and incidence of TGA and to clarify terminology and classification.