LAUSR

Objectives Myopericarditis is a newly described entity that is primarily a pericardial syndrome with elevated cardiac enzymes that has been seen with increasing frequency in our pediatric intensive care unit. For this reason, we performed a retrospective cohort analysis with a goal of establishing differences between myopericarditis and myocarditis that could lead to proper diagnosis on emergency department presentation. Methods A database query was performed and identified patients over a 9-year period, and clinical data, laboratory data, and cardiac studies were extracted and analyzed from the electronic health record. Results A total of 36 patients were identified with the discharge diagnosis of myopericarditis and 22 with myocarditis. The median age for myopericarditis patients was 16.2 years, and 97% were male. The median initial troponin was 7.1 ng/mL, the peak was at 16.6 ng/mL, and 58% had ST changes on electrocardiogram. The median length of stay for myopericarditis patients was 1.7 days, and 50% were discharged home on nonsteroidal anti-inflammatory medication. Compared with myocarditis, myopericarditis patients were older, had a higher incidence of chest pain, and were less likely to have fever, vomiting, abdominal pain, upper respiratory infection symptoms, chest radiograph abnormalities, or T-wave inversion (P < 0.05). Myopericarditis patients also had lower Pediatric Risk of Mortality version 3 scores, B-type natriuretic peptide levels, and higher left ventricular ejection fractions on admission (67% vs 41%; P < 0.05). A classification model incorporating initial left ventricular ejection fraction, B-type natriuretic peptide, electrocardiogram, and chest radiograph findings distinguished myopericarditis from myocarditis with correct classification in 95% of patients. Conclusions Myopericarditis is a relatively common cause of chest pain for patients admitted to the pediatric intensive care unit, presents differently than true myocarditis, and carries a good prognosis.