ABSTRACT
Background and Aim: Multi-system inflammatory syndrome in chil-dren (MIS-C) causes widespread systemic inflammation including a pancarditis in the weeks following a COVID infection. Further coronavirus surges appear inevitable and with vaccination rates lower in young people an understanding of the medium-term car-diac impacts of this condition is important for planning further treatment and understanding the impacts on their health. Method(s): A retrospective single-center study of 67 consecutive patients with MIS-C was performed. Three time points were determined as the point of worst cardiac dysfunction during the acute admission, then at intervals of 6-8 weeks and 6-8 months. Echocardiographic findings were used to evaluate both 2D and 3D measures of cardiac function. Coronary artery measurements were recorded. Corresponding serial ECG findings were evaluated. Result(s): The worst cardiac function arose 6.8 +/- 2.4 days after the onset of fever. The mean M mode-derived FS was 30.9 +/- 8.1% during the acute phase. The mean 3D left ventricle (LV) ejection fraction (EF) was borderline at 50.5 +/- 9.8%. A pancarditis was typ-ically present: 46.3% showed cardiac impairment;31.3% had some pericardial effusion;26.8% had moderate (or worse) valvar regur-gitation and;26.8% had coronary dilatation. Cardiac function returned to normal in all patients by 6-8 weeks (mean 3D LV EF 61.3 +/- 4.4%, plt;0.001 compared to admission). Coronary dila-tation normalized in all but one patient who initially developed large aneurysms at presentation;these continued 6 months later. ECG findings mainly featured T-wave changes resolving at fol-low-up. There were a small number of adverse events: need for ECMO (2), death as an ECMO-related complication (1), suben-docardial infarction (1), LV thrombus formation (1). Conclusion(s): MIS-C causes a pancarditis with decreased cardiac function and almost a quarter of patients showing coronary changes. In most, discharge from long-term follow-up can be con-sidered as full cardiac recovery is expected by 8 weeks. The excep-tion includes patients with medium sized aneurysms or greater or those with more of a Kawasaki disease phenotype as these require on-going surveillance for persistence of coronary changes.