The Fate of the Retrained Left Ventricle After Double Switch Procedure for Congenitally Corrected Transposition of the Great Arteries

Abstract

In congenitally corrected transposition of the great arteries (CCTGA) there is atrioventricular and ventriculoarterial discordance so that the systemic circulation is supported by the morphologic right ventricle (RV). These may require repair when there are associated cardiac anomalies such as ventricular septal defect, pulmonary stenosis, and tricuspid valve anomalies. In addressing only the associated anomalies, conventional or physiologic repair leaves the morphologic RV in the systemic circulation. Longterm follow-up by many centers has documented deteriorating right ventricular function with tricuspid regurgitation with this approach and survival at 1 year of 84%, declining to 60% at 15 years. 1 The morphologic left ventricle (LV) can be restored to the systemic circulation with an atrial, arterial switch procedure, the so called “double switch.” For this to be successful, the morphologic LV may need retraining by application of a pulmonary artery band. We were interested in the fate of this retrained LV and wondered whether it would be as robust as a LV subjected to systemic pressures from birth. Thus, we reviewed our patients with CCTGA who had undergone a double switch procedure to see if we could detect a difference in outcome in ventricular function between the trained and untrained LV.