Abstract
Background: Cardiac injury has been described in children with both
acute COVID-19 and the multisystem inflammatory syndrome in children
(MIS-C). Strain has been shown to be a sensitive measure of systolic
function and can be used for detecting subclinical left ventricular (LV)
dysfunction. We sought to describe strain findings in both groups on
initial presentation and outpatient follow up. Methods: A retrospective
study analyzing echocardiograms of all patients presenting with acute
COVID-19 infection and MIS-C at our institution between March 2020 and
December 2020 was performed. TOMTEC software was used for strain
analysis in both study groups (COVID-19 and MIS-C) and age matched
healthy controls. Regional strain was obtained and comparison amongst
groups was performed using the Mann-Whitney U test. Strain was compared
against LV ejection fraction (EF) as measured by 5/6 area length method.
Results: 45 patients (34 MIS-C and 11 COVID-19) met inclusion criteria.
There was a statistically significant decrease in LV longitudinal strain
(p <0.001), LV circumferential strain (p <0.001) and
left atrial strain (p = 0.014) in the MIS-C group when compared to the
control group. There was a statistically significant decrease in LV
longitudinal strain (p = 0.028) in the acute COVID-19 group. All
patients with abnormal LVEF had abnormal strain. However 14 patients
(41%) in the MIS-C group and 3 (27%) in the acute COVID-19 group had
preserved LVEF but abnormal strain. Abnormal strain persisted in
one-third of patients in the MIS-C and acute COVID-19 groups on
outpatient follow up. Conclusion: Patients with MIS-C and acute COVID-19
can develop myocardial dysfunction as seen by abnormal strain. Strain
may provide an additional tool in detecting subtle myocardial
dysfunction. It can be routinely employed at diagnosis and at follow up
evaluation of these patients.