In this complex malformation the ventricles are on the opposite side of the heart to the usual. The atriums are connected to the incorrect ventricles and the great arteries also come from the wrong ventricles (Transposition). Despite these problems, blood from the lungs passes to the aorta, so the child is not blue. In individuals who have no other heart defects the heart may function well enough for the affected person to survive to adult life without symptoms

In many cases  an associated VSD is present (as shown in the illustration). This allows excessive blood flow and pressure in the lung circulation. Other heart defects are commonly present (eg valve abnormalities, coarctation, pulmonary stenosis). Many patients develop 'Heart Block', which may necessitate a pacemaker.

A related abnormality is "Double Inlet Left Ventricle" (DILV).