Discordant Atrioventricular Connections 2: Congenitally Corrected Transposition with Ventricular Septal Defect

In the second videoclip exploring congenitally corrected transposition, we show a specimen in which the potentially corrected circulatory patterns are uncorrected to a degree by the presence of a ventricular septal defect. More than half the patients with congenitally corrected transposition have deficient ventricular septation, and as in the heart shown, most usually the defects are perimembranous, opening to the inlet of the left-sided morphologically right ventricle. The key surgical feature of such defect is the anomalous position of the atrioventricular conduction axis, which runs antero-cephalad relative to the ventricular septal defect and the subpulmonary outflow tract. The location of the abnormal axis is shown in the videoclip. In the conclusion to the demonstration, we state that we do not hold a heart in the Idriss archive in which there is also co-existing pulmonary stenosis. This is not, in fact, true. We had neglected to observe that the heart shown as the final example in the fourth video has pulmonary stenosis in the setting of congenitally corrected transposition with mirror-imaged atrial chambers.