An<unk>  is a congenital heart defect where the<unk>  is positioned directly over a ventricular septal defect, instead of over the left ventricle.
The result is that the<unk>  contains some blood from the right ventricle, which reduces the amount of oxygen in the blood.
It is one of the four conditions of the Tetralogy of Fallot.
Overriding aorta
Over-riding of the aorta
Coronary artery dual ostia
Double inferior vena cava
Bicuspid aortic stenosis anatomy
Diaphragmatic eventration
Paradoxical septal motion
Pericardial calcification