Persistent left superior vena cava connecting through coronary sinus to left-sided atrium

A rare, congenital vascular malformation of the major vessels characterized by a persitent left superior vena cava which drains through the left coronary sinus to the left atrium. Patients are usually asymptomatic and discovered incidentally, however hypoxia, cyanosis, murmurs, palpitations, cardiac structural anomalies (e.g. atrial septal defect, bicuspid aortic valve, cor triatriatum) and risk of paradoxical embolism may be associated.