Acute myopericarditis with focal ECG findings mimicking acute myocardial infarction.

Background: Although history, physical examination, laboratory data points, and electrocardiogram (ECG) are helpful, distinguishing among pericarditis, myopericarditis, and myocardial infarction can be difficult.

Objectives: This case, which presents as pericarditis with concomitant myocarditis (myopericarditis), illustrates the four evolving ECG stages of pericarditis and highlights some of the potential difficulties in differentiating between myopericarditis and acute myocardial infarction.

Case Report: We present the case of a previously healthy 15-year-old boy who presented to the Emergency Department (ED) from his family physician's office for chest pain and presumed pericarditis. The patient's initial ECG showed infero-lateral ST-segment elevation, and his troponin T was elevated at 1.54 ng/mL (ref. < 0.03). Several hours after presentation to the ED, the patient experienced "10/10" chest pain, and a repeat ECG showed ST elevation increased from the prior ECG. After an emergent echocardiogram revealed no regional wall abnormalities, he was transferred to a pediatric cardiac intensive care unit, where a heart catheterization revealed no coronary irregularities. He was discharged 4 days later with the diagnosis of myopericarditis.

Conclusion: This case report illustrates some of the difficulties in differentiating among myopericarditis and myocardial infarction in a 15-year-old patient presenting with chest pain.