Cor triatriatum dexter: A rare cause of childhood cyanosis

Cor triatriatum dexter is a rare congenital heart anomaly where the right atrium is divided into two chambers by a membrane. We report a boy who had persistent mild cyanosis and diagnosed to have cor triatriatum dexter with secundum atrial septal defect by transoesophageal echocardiography. Interestingly, he had persistent mild cyanosis despite insignificant obstruction to the right ventricular inflow and normal pulmonary artery pressure. The pathophysiology, approach to the diagnosis, and mode of treatment are also discussed.