 This procedure, a form of atrial switch, was developed and first performed by Senning in 1957 as a treatment for d-TGA (dextro-Transposition of the great arteries) before improvements in cardiopulmonary bypass made more curative surgical techniques feasible.In this common congenital heart defect, the venous circulation drains into the right ventricle but from this chamber, blood is directed towards the systemic circulation through the aorta.This is also expressed by the term ventriculoarterial discordance, that is the ventricles are connected to the wrong great artery (the right ventricle to the aorta, thus pumping blood from the systemic venous back into the systemic arterial circulation).