Above.  Post delivery graphic anatomy.  The aorta (AO) and pulmonary artery (PA) are transposed or switched in dextro-transposition of the great arteries (D-TGA).  The aorta arises from the right ventricle instead of the left ventricle, and the pulmonary artery arises from the left ventricle instead of the right ventricle.  The coronary arteries arise from the transposed aorta.  The AO is to the right of the PA, and the two great vessels (the PA and the AO) are in a parallel orientation.

After birth, the systemic blood to the body does not receive oxygen from the lungs.  The blood that is oxygenated is pumped from the left side of the body to the lungs.  The vital organs, including the heart, do not receive adequate amounts of oxygen.  Therefore, the blood circulates in two circuits, and neonatal intervention is needed.  A large atrial septal defect (ASD) or ventricular septal defect (VSD) is necessary for survival.

Image courtesy of:  The Childrens’ Heart Clinic, PA, and Childrens’ Hospitals and Clinics of Minnesota.