Cor triatriatum: report of an unusual variant--triatrial heart. A case report.

Cor triatriatum is a rare cardiac malformation presenting with symptoms and signs of pulmonary venous obstruction. Although diagnosis of this defect has been facilitated by diagnostic procedures such as echocardiography and angiocardiography, it could be missed preoperatively. The authors report a case of cor triatriatum that is unique in having two separate atrial septal defects in each side of the fibromuscular membrane and that was undiagnosed preoperatively with transthoracic echocardiography and cardiac catheterization.