A patient in their 30s with no known medical history presented to the emergency department with 6 hours of vertigo, vomiting, dysarthria, and left-sided weakness. They denied any chest pain or shortness of breath. Vital signs were normal. A brain computed tomographic scan (CT) was consistent with a large infarction of the left cerebellar hemisphere and left pontine. An electrocardiogram (ECG) obtained on admission is shown in Figure, A. Subsequent investigation revealed a troponin T level of 1349 pg/mL (reference range, <14 pg/mL) and an N-terminal probrain natriuretic peptide level of 1674 pg/mL (reference range, <125 pg/mL). Test results for thrombophilia, vasculitis, and antiphospholipid syndrome were all negative. Echocardiogram showed regional wall-motion abnormalities of the left ventricle with a reduced ejection fraction of 36%. The patient was initially diagnosed with acute ischemic stroke and ST-segment elevation myocardial infarction (STEMI).