A clinical review of acute myocarditis in children

Purpose The aims of this study are to document our single-center experience with pediatric acute myocarditis and to investigate its clinical features and outcomes. Methods We performed a retrospective chart review of all children aged <16 years who were diagnosed with acute myocarditis between January 2006 and January 2015. We analyzed the following data: initial symptoms, laboratory findings, treatment, and outcomes. We divided patients into two groups according to severity. Results Twenty-nine patients were diagnosed with acute myocarditis. Thirteen patients (45%) survived to discharge, 4 patients (14%) died, and 12 patients (41%) who required extracorporeal membrane oxygenation were transferred. There was no significant age-related differences in the incidence of myocarditis between children <12 months (45%) and those >12 months (55%) of age. The overall incidence of upper respiratory tract infection symptoms was 69%; general symptoms, 66%; cardiac symptoms, 24%; gastrointestinal symptoms, 17%; and neurologic symptoms, 10%. Twelve patients (41%) had cardiomegaly. Ten patients had electrocardiographic abnormalities (tachycardia, ST changes, T wave changes, and low voltage). Echocardiographic abnormalities were pericardial effusion or impaired contractility. Severe group consisted of 13 patients who were either transferred or died and contained more patients with cardiomegaly and electrocardiogram abnormalities, but this was statistically irrelevant. Most patients had elevated concentrations of cardiac biomarkers, but the median concentrations were not statistically different between the 2 groups. Main treatment modalities included antibiotics (90%), inotropics (59%), and intravenous immunoglobulin (76%). Conclusion Definite diagnostic criteria for acute myocarditis do not exist, so misdiagnosis can occur. Extracorporeal membrane oxygenation therapy for severe cases is available only in some hospitals, so proper treatment can be delayed. Further evaluation of the current situation regarding acute myocarditis will contribute towards proper treatment.