Occult Penetrating Trauma: A STEMI Mimic Hiding in Plain Sight.

BACKGROUND

We report a case of acute pericarditis caused by an occult penetrating foreign body manifesting as an ST-segment elevation myocardial infarction mimic.

CASE SUMMARY: The patient initially presented with chest pain, increased cardiac troponin I, and ST-segment elevation. Following emergency intravenous thrombolysis and urgent coronary angiography, an alternative etiology was suspected. Subsequent verification of the medical history and imaging examinations ultimately identified the culprit: a nail. The patient received prompt treatment, and the pericardial foreign body was successfully extracted.

DISCUSSION: Acute pericarditis and acute myocardial infarction are common causes of acute chest pain. Diagnostic confusion and treatment delays may arise due to overlapping symptoms, elevation of cardiac biomarkers, ST-segment elevation, cognitive bias, and incomplete history taking.

TAKE-HOME MESSAGES: This case highlights the value of bedside echocardiography combined with chest radiography. In patients with suspected ST-segment elevation myocardial infarction, it is crucial to differentiate acute coronary occlusion from other causes, especially foreign body-induced pericarditis.