Congestive heart failure secondary to diffuse organized biventricular mural thrombus following mitral valve replacement.

A 52-year-old woman underwent mitral valve replacement for progresive mitral regurgitation. Despite anticoagulation therapy, pulmonary thromboemboli occurred. Progressive heart failure developed and fatal intracerebral hemorrhage occurred four years after valve replacement. Autopsy findings revealed a normal-sized heart with minimal ventricular hypertrophy. However, there was extensive organized mural thrombosis involving both ventricles. Endocardial thickening by diffuse organized thrombosis is an uncommon but severe complication following prosthetic valve replacement and may result in intractable heart failure from endocardial rigidity.