Atresia of the coronary sinus orifice

The cases of two children are reported in whom atresia of the right atrial orifice of the coronary sinus was diagnosed at cardiac catheterization. Only one previous case diagnosed in life has been found in the literature, though there are 34 necropsy reports. In nearly half the cases a persistent left superior vena cava has afforded the only outflow channel for the coronary sinus, and occasionally this may have surgical implications.