Cardiac Function in Pediatric Patients with MIS-C Using Speckle Tracking and Conventional Echocardiography: A Longitudinal, Single-Center Study.

Cardiovascular involvement in Multisystem Inflammatory Syndrome in Children (MIS-C), a potential consequence of coronavirus disease-2019 (COVID-19), is common. Conventional transthoracic echocardiography (TTE) provides primary data on the function of the left and right ventricles, while Speckle Tracking Echocardiography (STE) is more sensitive. This study aims to assess longitudinal cardiac function using STE in these patients. This longitudinal study was conducted from late 2021 to early 2022 at Imam Hossein Children's Hospital, Isfahan. Cardiac function was assessed by STE at the time of diagnosis and again two months later. Demographics, clinical characteristics, ECG interpretations, imaging studies, and serum cardiac marker levels were collected. Thirty-five pediatric patients with a mean age of 5.1 years (range: 4 months to 17 years) were included and prospectively followed. Twenty-nine of them, comprising 14 males (48.3%) and 15 females (51.7%), underwent STE and were compared with 29 healthy age- and sex-matched children. Factors related to adverse events included reduced myocardial function, enlarged left atrium or ventricle, and mitral regurgitation (MR). Patients with comorbidities affecting strain measurements were excluded from the strain analyses. A significant difference was observed between the groups in regional strains in the basal and apical septal and middle lateral regions. Global strain rate (GLS) and strain rates were not significantly different but were still lower than the control group. Twenty percent of patients had abnormal GLS but normal left ventricular ejection fraction (LVEF). All patients exhibited reduced segmental myocardial strain in at least one segment. Four out of 26 recovered patients without comorbidities had abnormal GLS at follow-up, despite normal LVEF. STE proves more useful than conventional echocardiography in patients with MIS-C, revealing subclinical cardiac injury in the acute and post-acute phases.