A rare cause of cyanosis in neonatal age: Cor triatriatum dexter

Cor triatriatum dexter is an extremely rare congenital anomaly that is caused by the partitioning of the right atrium by a broad sheet of tissue due to the persistence of the right sinus venosus valve. We describe a rare case of prominent right sinus venosus valve (cor triatriatum dexter) with consequent right-to-left shunt across the patent foramen ovale in a newborn with significant cyanosis.