Unsuspected amyloidosis and cardiac arrest following mitral valve replacement

We performed an autopsy on a 58-year-old female with previously unsuspected cardiac amyloidosis. One day prior to expiration the patient underwent a mitral valve replacement with a Bjork-Shiley prosthesis for mitral valve regurgitation. The valvular defect along with the massive myocardial amyloidosis which created a restrictive cardiomyopathy, were the etiology of the patient's poor cardiac output and subsequent demise.