[Diagnosis by endomyocardial biopsy: angina pectoris as a manifestation of lupus erythematosus].

A 64-year-old female patient with a prosthetic mitral valve suffered from recurrent typical angina and dyspnea. Left heart catheterization excluded a dysfunction of the prosthesis and coronary artery disease (CAD). A stress thallium scan demonstrated an ischemic reaction. An antimyosin scintigram was positive, indicating myocytal membrane disruption. Serological tests were suspicious for systemic lupus erythematosus (SLE). Therefore, an endomyocardial biopsy (EMB) was performed and a severe alteration of an intramyocardial artery, comparable with chronic SLE, was diagnosed. EMB is a useful diagnostic tool in patients with typical chest pain, positive thallium and anti-myosin scintigrams, however exclusion of CAD.