Coronary sinus atresia is usually a congenital anomaly. Sometimes it is due to an AV fistula involving the middle cardiac vein which becomes grossly enlarged and impinges on the coronary sinus ostium and closes it off.
Coronary sinus atresia is usually a congenital anomaly. Sometimes it is due to an AV fistula involving the middle cardiac vein which becomes grossly enlarged and impinges on the coronary sinus ostium and closes it off.