Echocardiographic assessment of cardiac involvement in pediatric COVID-19 patients: a cross-sectional study

Background Cardiac involvement has emerged as a significant complication in children with COVID-19, particularly in those with multisystem inflammatory syndrome in children (MIS-C). However, systematic echocardiographic data remain limited, especially from the Middle East. Methods In this descriptive cross-sectional study, 433 children with confirmed COVID-19 admitted to a tertiary hospital in Tehran were evaluated. Transthoracic echocardiography was performed in all patients during hospitalization. Cardiac function, valvular regurgitation, pericardial and pleural effusion, and coronary artery dimensions (Z-score–based) were recorded. Findings were compared between MIS-C and non–MIS-C patients. Results Among 433 patients (mean age 4.56 years; 54% male), 270 (62.5%) were diagnosed with MIS-C. The most common echocardiographic abnormalities were mitral regurgitation (19.4%) and pericardial effusion (18.5%). Coronary abnormalities (1.4%) and LV systolic dysfunction (4.8%) were uncommon. MIS-C patients had significantly higher rates of pericardial effusion (23% vs. 11%, p = 0.002). Pericardial effusion was the only variable significantly associated with ICU admission ( p = 0.002). Pleural effusion was observed only in non-MIS-C patients (3.1%, p = 0.003). Conclusions Echocardiographic abnormalities are common in children hospitalized with COVID-19, particularly those with MIS-C. Pericardial effusion may serve as an early marker of severity and guide triage. Routine cardiac imaging is recommended in hospitalized children with inflammatory symptoms.