Impaired function of cloth-covered Starr-Edwards mitral valve prosthesis. Detection by phonocardiography.

was suspected because of phonocardiographic abnormalities. A prolonged interval from aortic closure to opening of the mitral ball suggested an impediment to movement of the ball. This was confirmed by catheterization and cinefluorography. At autopsy the impaired ball movement was found to be due to thrombus buildup on the outflow face of the mitral valve orifice. It is suggested that frequent postoperative phonocardiographic observations may be useful in detecting malfunction of valvular prostheses.