[Mitral regurgitation with concomitant atrial septal aneurysm; report of a case].

A 64-year-old female was admitted to our hospital because of severe dyspnea. Echocardiography revealed mitral valve regurgitation and atrial septal aneurysm (ASA). After instituting medical treatment for congestive heart failure, euvolemic status was achieved, and the patient underwent; (1) prosthetic patch repair for ASA; (2) mitral valvuloplasty with partial quadrangular resection of the posterior mitral leaflet; and (3) mitral annuloplasty using Physio ring. Pathological examination revealed myxomatous degeneration of the mitral valve, but the resected atrial septum was without any abnormality. ASA can lead to cerebral or pulmonary embolism even in the absence of an atrial septal defect. However, ASA without atrial septal defect is typically asymptomatic and rarely requires surgical correction. By contrast, ASA with concomitant mitral valve prolapse is associated with a high risk of cerebral or pulmonary embolism. Aspirin therapy is indicated for the prevention of thromboembolism in patients with ASA who do not undergo surgical management, and these patients also require careful observation.