Congenitally corrected transposition with isolated atrial septal defect and apicocaval juxtaposition: a hitherto undescribed cardiac cause of central cyanosis.

In our practice, we have been struck by the presence of central hypoxemia in individuals with congenitally corrected transposition of the great arteries (CCTGA) with an atrial septal defect (ASD) as the only association, despite existence of normal pulmonary artery pressures. This right to left shunting at the atrial level occurs only in those patients where there is additional presence of apicocaval juxtaposition (ACJ). Patients with CCTGA but without ACJ manifest only left to right shunting at the level of the ASD. We present a case series of patients with CCTGA with intact ventricular septum and incomplete atrial septum with a possible basis for this phenomenon.