A very rare case of late diagnosis of cor triatriatum sinistrum.

We presented a 73-year-old patient with a history of hospitalizations for heart failure as well as treatment for arterial hypertension and permanent atrial fibrillation and who was found to have cor triatriatum sinistrum in combination with bicuspid aortic valve. Patient refused surgical correction, but his condition improved on conservative therapy for heart failure and atrial fibrillation.