[Cor triatriatum sinistrum and atrial septal defect].

The cor triatriatum sinistrum is a rare congenital malformation. Frequently, the patients become symptomatic in infancy with clinical signs of severe congestive heart failure. We report on an adult patient with only mild symptoms with cor triatriatum sinistrum and atrial septal defect. The embryological basis of the disorder and the hemodynamic conditions which permitted this patient to remain symptom free for a long period are discussed.