ABSTRACT
Background and Aim: The objective of the study was to assess the features of acute myocarditis and compare Covid19 and non-Covid19 cases. Method(s): Patients lt;18y with acute myocarditis (proved by virology and/or MRI and/or complete recovery of myocardial function) were included. Clinical data, echocardiographic parameters and outcomes were collected. Cases were divided in groups I (non-Covid), II (Covid). Result(s): From 1983 to 2021, 139 patients were included: 76 patients in group I and 63 in group II, 67males (31 in group I = 40% vs 36 in II = 57%). Mean age at diagnosis was 6.8 years: 4.2 years in group I vs 9.9 years in II. Heart failure (HF) was present at onset in 78% of cases in group I and 50% in group II: severe HF was more frequent in group I, chest pain was more frequent in II. Mean left ventricular shortening fraction (LVSF) at diagnosis was 23.8%: 18.4% in groups I vs 31.6% in II (plt;0.05). Mitral regurgi-tation was present in 63.8% of cases = 76.5% vs 43.8% respectively in groups I and II, pericarditis in 16.4% (no difference between groups), thromboembolic events occurred in 7% and arrhythmias in 10% ((all in group I). Virus was positive in 37.5% in group I and SARS-Cov2 positive in all of group II. Inotrope support was needed in 47%, mechanical circulatory support in 8% in group I only. Eleven patients died in group I, no death occurred in group II. One was transplanted(3rdmonth) and 19 have sequellae in group I. Complete recovery occurred in 74% of all cases: 40 of group I (58%) and all of group II (100%): time to recovery was longer in group I (2 years) than in group I (2 weeks). Mean LVSF improved from 18.4% at onset, to 24.6% at 1st month, 26.5% at 3rd month, 30.7% at 6th month and 38% at last FU in group I, while mean LVSF normalized within 2 weeks after onset in group II. Conclusion(s): Myocardial dysfunction and heart failure were less fre-quent, and complete recovery occurred promptly in COVID cases, while myocardial improvement progressed slowly within first 6months and beyond in half of non-COVID cases.