Persistent ST-segment elevation mimicking ST-elevation myocardial infarction.

ST-segment elevation on electrocardiography is classically associated with acute myocardial infarction and often prompts urgent invasive evaluation. However, non-ischemic causes may complicate diagnostic decision-making, particularly in elderly patients with acute non-cardiac illnesses. We report a 95-year-old woman admitted with COVID-19-associated pneumonia and aspiration pneumonia, whose admission electrocardiogram demonstrated ST-segment elevation with T-wave inversion in the lateral precordial leads, mimicking ST-elevation myocardial infarction. She had no chest pain, no elevation of cardiac biomarkers, and preserved left ventricular systolic function without regional wall motion abnormalities on echocardiography. Review of prior records revealed that similar electrocardiographic abnormalities had been consistently present for more than a decade. Serial imaging demonstrated no overt structural heart disease. However, the electrocardiographic pattern-localized and persistent ST-segment elevation with repolarization abnormalities-is most consistent with chronic localized myocardial remodeling, possibly related to unrecognized myocardial fibrosis. This case highlights the importance of integrating clinical presentation, biomarkers, and longitudinal electrocardiographic findings. Persistent ST-segment elevation does not always indicate acute coronary occlusion, but may reflect an underlying structural myocardial substrate not detectable by routine imaging.