Spontaneous pneumomediastinum mimicking acute pericarditis.

ST elevations on electrocardiogram (ECG) have a broad differential diagnosis that can vary from benign to more ominous pathologies. These include early repolarization, coronary vasospasm, acute pericarditis, ST-elevation myocardial infarction, ventricular aneurysms, and dissecting aneurysm of the aorta reaching the pericardium. ST-segment changes may also provide a clue to the presence of spontaneous pneumomediastinum (SPM).