Transposition of the great vessels

TGV is a serious heart defect that arises through a maldivision of the arterial truncus which gives rise to the aorta and the pulmonary artery. It means that the aorta emerges from the right ventricle and the pulmonary truncus from the left ventricle, instead of vice versa. For long term survival an operation is performed and prognosis is fair.

The recorded rates of this cardiac malformation vary immensely -- from very low rate around 1 : 20,000 to 1 : 2,500 -- for which there is no obvious explanation at present other than diagnosis procedures and length of follow-up time of the infants.