Coronary embolism in patients with mitral valve prosthesis.

M yocardial infarction secondary to coronary embolization is infrequently encountered. Approximately 100 cases have l)een reported with the majority being associated with bacterial endocarditis or syphilis.’ Other causes are paradoxic embolization from atrial or ventricular mural thrombi, avulsed tissue or tumor2 and mitral stenosis with atrial fibrillation. a Coronary embolization has also been reported in rare instances from thrombi or tumor invading the pulmonary veins,4 after pneumonectomy and in cases of tumor invasion of the left atrium.46 Since the advent of prosthetic valvular surgery, another source for coronary emboli has been introduced, ie fragnients of the prosthetic material7 or more commonly thrombus formed at the surface of the prosthesis. In 1964, Bjork and Malers8 on discussing the late results of mitral valve replacement, reported the first case of coronary embolism arising from a mitral prosthesis. There have been five subsequent cases reported in detail of similar episodes.#{176}12 It is the purpose of this paper to report three cases of coronary embolus resulting in acute myocardial infarction in patients with prosthetic mitral valves.