Background: Acute myocardial infarction is a rare complication of mitral stenosis. Acute myocardial infarction in the setting of severe unrecognized mitral stenosis has not been described.
Case report: A 47-year-old-woman was admitted to our department for chest pain typical of myocardial infarction. Electrocardiogram showed ST segment elevation in leads II, III, and aVF and atrial fibrillation. Creatine kinase level was elevated to 268 U/L. The diagnosis of acute myocardial infarction of the inferior wall was established. The patient reported breathlessness after physical exertion over the last 2 years; however, she had not sought medical help and was unaware of her heart disease. Transthoracic echocardiography showed severe mitral stenosis (surface mitral valve area <1 cm2) and inferior wall akinesia.
Conclusions: We present a case of acute myocardial infarction in a patient with unrecognized severe mitral stenosis and atrial fibrillation. Our suggestion is that acute myocardial infarction in this patient with no risk factors for coronary atherosclerosis was of thromboembolic origin, from left atrial thrombi.