TGA

Transposition of the great arteries: a condition characterised by the aorta arising from the right ventricle and the pulmonary artery from the left ventricle; often associated with other cardiac abnormalities (e.g. ventricular septal defect). Newborns with transposed great arteries are very likely to die without an arterial switch operation. The operation, as the name implies, involves switching the aorta and pulmonary arteries back to their correct positions.