RESUMO
Introduction and importance: Chronic rheumatic heart disease is the most common cause of mitral stenosis. It remains a major public health problem. In almost half of the cases, paroxysmal or chronic atrial fibrillation occurs during the evolution of mitral stenosis, thereby exposing to an increased risk of thrombo-embolic events.Whereas the most frequent site for embolism is the cerebral circulation, any organ may be involved, especially the coronary circulation, resulting in a myocardial infarction (MI). Case presentation: Here, we report a rare case of a 50-year-old patient, with no risk factors for cardiovascular disease, presenting an acute ST-elevation myocardial infarction (STEMI) as initial presentation of unknown mitral stenosis with atrial fibrillation and strongly suggesting an embolic origin. The diagnosis was made based on the national cerebral and cardiovascular center (NCVC) criteria for the clinical diagnosis of coronary artery embolism (CE). Coronary angiography showed a distal thrombus in the right coronary artery that has been medically treated. The outcome was favorable and the patient was referred after that for mitral valve replacement.