Parapneumonic ST segment elevation

The presence of ST-segment elevation on the 12-lead electrocardiogram in a patient with suggestive symptoms of myocardial infarction should trigger an early diagnosis of ST-segment elevation myocardial infarction and urgent intervention to restore coronary perfusion, usually by percutaneous coronary intervention. However, several diseases and conditions can mimic an acute myocardial infarction or the ST-segment elevation pattern on the electrocardiogram. We report a clinical case of a patient hospitalized with the first diagnosis of pneumonia, who developed a de novo anteroseptal ST-segment elevation on electrocardiogram and clinical pain suggestive of transmural myocardial infarction. Emergent coronary angiography excluded coronary heart disease, and further investigation led to an unexpected final diagnosis.