Absent right superior vena cava with left superior vena cava draining into unroofed coronary sinus with common atrium in a child with an atrioventricular septal defect.

The association of absent right superior vena cava and persistent left superior vena cava draining into unroofed coronary sinus with common atrium and the atrioventricular septal defect is an extremely rare form of the congenital cardiac disorder with only one case reported so far, hence, can be missed preoperatively if not carefully looked for. Failure to detect absent right superior vena cava beforehand may otherwise pose difficulties in carrying out invasive surgical or medical interventions.