Medium-Term Cardiac Outcomes in Young People with Multi-system Inflammatory Syndrome: The Era of COVID-19.

Multi-system inflammatory syndrome in children (MIS-C) causes widespread inflammation including a pancarditis in the weeks following a COVID infection. As we prepare for further coronavirus surges, understanding the medium-term cardiac impacts of this condition is important for allocating healthcare resources. A retrospective single-center study of 67 consecutive patients with MIS-C was performed evaluating echocardiographic and electrocardiographic (ECG) findings to determine the point of worst cardiac dysfunction during the admission, then at intervals of 6-8 weeks and 6-8 months. Worst cardiac function occurred 6.8 ± 2.4 days after the onset of fever with mean 3D left ventricle (LV) ejection fraction (EF) 50.5 ± 9.8%. A pancarditis was typically present: 46.3% had cardiac impairment; 31.3% had pericardial effusion; 26.8% demonstrated moderate (or worse) valvar regurgitation; and 26.8% had coronary dilatation. Cardiac function normalized in all patients by 6-8 weeks (mean 3D LV EF 61.3 ± 4.4%, p < 0.001 compared to presentation). Coronary dilatation resolved in all but one patient who initially developed large aneurysms at presentation, which persisted 6 months later. ECG changes predominantly featured T-wave changes resolving at follow-up. Adverse events included need for ECMO (n = 2), death as an ECMO-related complication (n = 1), LV thrombus formation (n = 1), and subendocardial infarction (n = 1). MIS-C causes a pancarditis. In the majority, discharge from long-term follow-up can be considered as full cardiac recovery is expected by 8 weeks. The exception includes patients with medium sized aneurysms or greater as these may persist and require on-going surveillance.

Electrocardiographic Changes in Children with Multisystem Inflammation Associated with COVID-19: Associated with Coronavirus Disease 2019.

OBJECTIVE: To analyze findings and trends on serial electrocardiograms (ECGs) in multisystem inflammatory syndrome in children (MIS-C) associated with coronavirus disease taken during the course of illness and at follow-up. STUDY DESIGN: We included all children presenting with MIS-C at a single center with 3 or more ECGs taken during the course of their illness. We measured ECG intervals (PR, QRSd, and QTc) and amplitudes (R-, S-, and T-waves) on each ECG and documented any arrhythmias and ST-segment changes. RESULTS: A majority of children (n = 42, 67%) showed ECG changes. The most common findings were low QRS amplitudes and transient T-wave inversion. ST changes were uncommon and included ST-segment elevation consistent with pericarditis in 1 child and acute coronary ischemia in 1 child. Arrhythmias were seen in 13 children (21%) but were benign with the exception of 1 child who was compromised by an atrial tachycardia requiring support with extracorporeal membrane oxygenation. No children were found to have high-grade atrioventricular block. CONCLUSIONS: MIS-C is associated with electrocardiographic changes over the course of the illness, with low amplitude ECGs on presentation, followed by transient T-wave inversion, particularly in the precordial leads. There was a low prevalence of ST-segment changes and tachyarrhythmias.