Undiagnosed cardiac sarcoidosis causing refractory heart failure after acute myocardial infarction due to thromboembolism

A 61-year-old woman suffered chest pain and was admitted to a nearby hospital emergency department. She was diagnosed with acute myocardial infarction probably due to thromboembolism in the left anterior descending coronary artery and aspiration thrombectomy was performed. Afterwards, she developed refractory heart failure with severe global left ventricular dysfunction and was transferred to our hospital. An 18F-FDGPET/ CT scan revealed abnormal 18F-FDG uptake in non-infarcted regions of the left ventricle. Non-caseating granulomas were detected by biopsy from a skin eruption. She was diagnosed with cardiac sarcoidosis. In cases of refractory heart failure which cannot be explained only by myocardial infarction, evaluation of other undiagnosed cardiomyopathies is important for optimal management.