Transposition of the great arteries (TGA) is a congenital cardiac defect in which the aorta arises
entirely or largely from the right ventricle (RV) and the pulmonary trunk arises entirely or
largely from the left ventricle (LV). This is known as a ventriculo-arterial discordant
connection(1).
There are two different forms of TGA, complete TGA and congenitally corrected TGA
(ccTGA). In ccTGA (also named L-TGA), the atrio-ventricular and ventriculo-arterial
connections are discordant, the lower part of the heart being ‘inversed’. Due to this double
discordance, we can observe a ‘physiological’ correction of circulation with however, a
systemic right ventricle(2) (Figure 1). It is different from and much less common than complete
TGA (also called dextro-TGA or d-TGA).