To evaluate the factors associated with intensive care requirement and mortality in pediatric myocarditis.

Children aged 28 days to 18 years who were diagnosed with acute myocarditis in a pediatric emergency department between January 2010 and September 2020 were enrolled in the study retrospectively. Demographic and clinical features, cardiac biomarkers, and imaging findings were evaluated. Length of hospital stay, need for hospitalization in the pediatric intensive care unit (PICU), treatments, and survival outcomes were recorded. To define the severity of disease, three groups were created and the data were compared in terms of clinical, laboratory, and imaging findings. The patients treated in the pediatric ward were compared with those hospitalized in the PICU. Ventricular dysfunction was defined in patients with a left ventricular ejection fraction (LVEF) of <50% and these patients were compared with those who had an LVEF of >50%. Also, survivor and non-survivor patients were compared.

A total number of 62 patients with a median age of 8 years were included. Chest pain and tachycardia were the most common findings on physical examination. The mean LVEF was 59.3 ± 13.0% at admission. Of the patients, 17 were hospitalized in the PICU (27.4%). Chest pain was more common in patients hospitalized in the pediatric ward (p<0.001), and hypotension, vomiting, arrhythmia, were more common and LVEF was lower in patients in the PICU (p = 0.017, p = 0.008, p = 0.006, and p = 0.025, respectively). The children treated in the PICU were younger than those in the pediatric ward (p = 0.009). Troponin I levels were significantly higher in the pediatric ward (p = 0.035), and brain natriuretic peptide (BNP) levels were higher in patients in the PICU (p = 0.012). Death occurred in four patients. Hypotension and vomiting were significantly more common in non-survivors (p = 0.020 and 0.004, respectively). Inotropes and intravenous immunoglobulin (IVIG) were more commonly used in non-survivors (p = 0.001 and p = 0.015, respectively). BNP levels were higher in non-survivors (p = 0.008), and troponin I levels were not different between survivors and non-survivors (p = 0.260).

In pediatric acute myocarditis, lower LVEF, increased BNP, as well as the presence of hypotension and arrhythmia were found to be related to intensive care requirement. Hypotension and vomiting were found to be more common in non-survivors. Due to the possibility of rapidly worsening disease, physicians should be alert to the presence of these findings.