Incidental cor triatriatum discovered on multidetector computed tomography.

A 78-year-old woman presented with increasing dyspnea on walking, occasional chest pain, and a single episode of presyncope. An echocardiogram showed a calcified aortic valve with severe aortic stenosis. A computed tomography scan showed a functionally bicuspid aortic valve and moderate calcification of the leaflets. An incidental fine linear membrane was seen traversing the left atrium, dividing the chamber consistent with cor triatriatum. The imaging appearance of cor triatriatum is characteristic and can be easily differentiated from supravalvular mitral ring and intraatrial thrombus. In adult patients, it usually has a large fenestration and is of no significance. In children, the fenestration may be small or absent, and surgical treatment may be required.