To determine the utility of screening electrocardiograms after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among children in detecting myocarditis related to coronavirus disease 2019 (COVID-19).

A retrospective chart review was performed at a large paediatric academic institution to identify patients with prior SARS-CoV-2 infection who received a screening electrocardiogram by their primary care providers and were subsequently referred for outpatient cardiology consultation due to an abnormal electrocardiogram. The outcomes were the results from their cardiology evaluations, including testing and final diagnoses.

Among 46 patients, during their preceding COVID-19 illness, the majority had mild symptoms, 4 were asymptomatic, and 1 had moderate symptoms. The median length of time from positive SARS-CoV-2 test to screening electrocardiogram was 22 days, and many electrocardiogram findings that prompted cardiology consultation were normal variants in asymptomatic adolescent athletes. Patients underwent frequent additional testing at their cardiology appointments: repeat electrocardiogram (72%), echocardiogram (59%), Holter monitor (11%), exercise stress test (7%), and cardiac MRI (2%). Five patients were incidentally diagnosed with CHD or structural cardiac abnormalities, and three patients had conduction abnormalities (pre-mature atrial contractions, pre-mature ventricular contractions, borderline prolonged QTc), although potentially incidental to COVID-19. No patients were diagnosed with myocarditis or ventricular dysfunction.

In a small cohort of children with prior COVID-19, who were primarily either asymptomatic or mildly symptomatic, subsequent screening electrocardiograms identified various potential abnormalities prompting cardiology consultation, but no patient was diagnosed with myocarditis. Larger multi-centre studies are necessary to confirm these results and to evaluate those with more severe disease.