Ruptured mitral valve aneurysm in a patient with quadricuspid aortic valve.

Mitral aneurysm is commonly associated with infectious endocarditis of the aortic valve. In rare instances, it is associated with other underlying inflammatory or metabolic disorders. A 62-year-old man with mitral valve insufficiency with moderate aortic valve insufficiency underwent operation. Operative findings were the ruptured aneurysm of the mitral valve in association with the calcified quadricuspid aortic valve. There was no evidence of infection in the mitral valve and the aortic valve. The mitral valve was repaired, the aortic valve replaced, and Cox Maze procedure added. A rare combination of mitral and aortic valve lesions without endocarditis suggested that mechanical stress alone may induce mitral valve aneurysm.