ABSTRACT
Purpose: CMR derived left ventricular longitudinal and circumferential strain is known to be abnormal in myocarditis. CMR strain is an useful additional tool that can identify subclinical myocardial involvement and may help with longitudinal follow-up. Right ventricular strain derived by CMR in children has not been studied. We sought to evaluate CMR derived biventricular strain in children with acute myocarditis. Methods: Children with acute myocarditis who underwent CMR 2016 - 2022 at our center were reviewed, this group included subjects with COVID-19 myocarditis. Children with no evidence of myocarditis served as controls Those with congenital heart disease and technically limited images for CMR strain analysis were excluded from final analysis. Biventricular longitudinal, circumferential, and radial peak systolic strains were derived using Circle cvi42. Data between cases and controls were compared using an independent sample t-test. One-way ANOVA with post hoc analysis was used to compare COVID-19, non-COVID myocarditis and controls. Results: 38 myocarditis and 14 controls met inclusion criteria (14.4 ± 3 years). All CMR derived peak strain values except for RV longitudinal strain were abnormal in myocarditis group. One-way ANOVA revealed that there was a statistically significant difference with abnormal RV and LV strain in COVID-19 myocarditis when compared to non-COVID-19 myocarditis and controls. Conclusion: CMR derived right and left ventricular peak systolic strain using traditionally acquired cine images were abnormal in children with acute myocarditis. All strain measurements were significantly abnormal in children with COVID-19 even when compared to non COVID myocarditis.