Cor Triatriatum Sinister Associated with Total Anomalous Pulmonary Venous Connection.

Cor triatriatum sinister is rare congenital heart disease. It is defined as the presence of an abnormal septum dividing the left atrium into two chambers, and in some cases may be associated with a total abnormal pulmonary venous connection. Prenatal diagnosis of cor triatriatum sinister may be possible with fetal echocardiography and the diagnosis can be made earlier than postnatal imaging techniques. In the fetal echocardiography performed in our patient, cor triatriatum sinister was present and the main pathology was the flow of right and left pulmonary vein return from the accessory atrium to the right atrium.