Partially unroofed coronary sinus, persistent left superior vena cava and cortriatriatum: a rare combination of interruption in normal embryogenesis.

A 48-year-old male with a history of secundum type atrial septal defect (ASD) closure in childhood presented to our outpatient clinic complaining of palpitation for six months. Interestingly, transthoracic and transesophageal echocardiography exams showed an undiagnosed partially unroofed coronary sinus associated with persistent left superior vena cava (LSVC) and Cor triatriatum.