transposition of great arteries

transposition of great vessels a congenital anomaly of the cardiovascular system in which the aorta arises entirely from the right ventricle and the pulmonary artery from the left ventricle, so that the venous return from the peripheral circulation is recirculated by the right ventricle via the aorta to the systemic circulation without being oxygenated in the lungs. Life then depends on a crossflow of blood between blood in the right heart and that in the left heart, as through a ventricular septal defect or a patent ductus arteriosus. Cyanosis is the chief symptom.

Complete transposition of great arteries, patent foramen ovale, intact ventricular septum, and closed ductus arteriosus in an 8-month-old boy. A balloon atrial septostomy was performed at 6 days of age. (A), The right ventricle (RV) gives rise to the ascending aorta (AO), which is convex to the right. (B), The left ventricle (LV) gives rise to a centrally placed pulmonary trunk (PT) with a rightward inclination. The great arteries parallel each other and do not cross.