Asymptomatic pulmonary embolus masquerading as acute anteroseptal myocardial infarction.

Pulmonary embolism (PE) is an uncommon and often overlooked cause of ST-segment elevation on the electrocardiogram (ECG). Emergent echocardiography has been cited as a means to rapidly distinguish acute myocardial infarction from PE. However, both of these conditions can present with focal wall motion abnormalities. We report a case of a 51-year-old asymptomatic male who presented to our emergency department with anterior ST-segment elevation and right-heart strain on an ECG. The clinical diagnosis of ST elevation myocardial infarction was in doubt, and an echocardiogram was obtained while the patient was in the emergency department. Although a focal area of hypokinesia was observed on echocardiography, cardiac catherization did not demonstrate any evidence of acute coronary occlusion. A computed tomographic angiogram of the chest was subsequently obtained, which demonstrated evidence of submassive pulmonary emboli. Our case highlights the limited utility of emergent echocardiography in cases of ST-segment elevation.