Background: Patients with acute cardiac symptoms, elevated cardiac troponin, and culprit-free angiograms are a consistent proportion of patients admitted with presumed acute coronary syndromes (ACS). Current literature on this population of patients justifies the diagnostic importance of cardiovascular magnetic resonance (CMR) imaging.
Case Report: This report describes the case of a 58-year-old cyclist in which CMR allowed us to perform a diagnosis of myopericarditis mimicking acute STEMI against other evidence. There are several such reports in literature because the clinical presentation of myocarditis is quite variable.
Conclusions: This case report emphasizes the importance of cardiovascular magnetic resonance imaging in the differential diagnosis of the etiology of acute coronary syndromes. This is especially important because the signs and symptoms presented are ambiguous and equivalent to those of other diseases, such as myopericarditis, which affects mainly young athletes but also middle-aged athletes.

Keywords: myopericarditis, Myocardial infarction, Cardiovascular Magnetic Resonance