ST-elevation myocardial infarction (STEMI) is a clinical syndrome defined by characteristic symptoms of myocardial ischemia in association with persistent electrocardiographic ST elevation (STE) and subsequent release of biomarkers of myocardial necrosis. 1 STE is the single best immediately available surrogate marker for detecting acute complete coronary artery occlusion without collateral circulation, signifying a significant region of injured myocardium at imminent risk of irreversible infarction, requiring immediate reperfusion therapy. 2 Diagnostic STE is defined as new STE at the J point in at least 2 contiguous leads > 2 mm (0.2 mV) in men or > 1.5 mm (0.15 mV) in women in leads V2-V3 and/or of > 1 mm (0.1 mV) in other contiguous chest or limb leads. 3 The presence of reciprocal changes (manifested as ST depression in a region that approximates the vector 180 degrees opposite the major vessel of injury) increases the specificity of STE caused by STEMI. 4 New or presumably new left bundle branch block has been considered a STEMI equivalent. Reperfusion therapy should be administered to all eligible patients with STEMI who have experienced symptom onset within the previous 12 hours. 1 Primary percutaneous coronary intervention is the recommended method of reperfusion when it can be performed in a timely fashion by experienced operators, with a goal of first medical contact-toballoon time of 90 minutes or less. 5,6 v