Overview of pediatric myocarditis and pericarditis

Background: Pediatric myocarditis and pericarditis represent an inflammatory process of the myocardium and the pericardium, respectively. Myocarditis is most common in the pediatric population with rising prevalence during the recent coronavirus pandemic. Timely diagnosis and treatment are essential for improving the prognosis and for reducing the occurrence of long-term sequelae. Aim of review: Discuss the current state of myocarditis and pericarditis with respect to clinical presentation, newest diagnostic modalities, and up-to-date recommendations for treatment and follow-up; and to contrast conventional myocarditis with coronavirus (SARS-CoV-2) associated myocarditis. Key scientific concepts of review: Myocarditis represents a leading cause of sudden cardiac death, presumably because of fatal dysrhythmia in combination with various degrees of cardiomyopathy. The diagnostic process spans from the clinical presentation to certain EKG findings and serological or tissue markers of inflammation and cardiomyocyte injury, to characteristic findings on echocardiography and magnetic resonance imaging. Various historical, laboratory, hemodynamic, and imaging markers are associated with the prognosis. Treatment of myocarditis is mainly based on the suppression of the inflammation with intravenous immunoglobulin, whereas treatment of pericarditis is most effectively achieved with non-steroidal anti-inflammatory medications. Coronavirus induced cardiomyopathy seems to show a 15-fold increased incidence compared to conventional myocarditis in addition to higher mortality and morbidity. This stands in contrast to the other two milder forms of myocarditis that are related to SARS-CoV-2: Myocarditis as part of the multisystem inflammatory syndrome (MIS-C) and coronavirus mRNA vaccine related myocarditis. Due to the potential for sequelae, late complications, and recurrence, patients with myocarditis require long-term follow-up. Specific guidelines for return to athletic activity have been developed to reduce the sudden death risk.