Pathological ECG patterns in children during the acute period of COVID-19: intermediate results of a longitudinal study

To investigate the pattern, nature, and frequency of electrocardiographic (ECG) abnormalities in children during the acute phase of coronavirus disease 2019 (COVID-19) with mild to moderate clinical manifestations and to assess the potential involvement of the cardiovascular system. Materials and methods. A retrospective analytical study was conducted involving 249 pediatric patients aged 1 month to 18 years with laboratory-confirmed COVID-19 who were hospitalized in an infectious disease unit. The analysis focused on cardiac rhythm and conduction disturbances, abnormalities of ventricular repolarization, and other ECG syndromes. Results. Sinus rhythm was preserved in 228 (91.6%) patients; however, a substantial proportion of children demonstrated various electrocardiographic abnormalities. The most frequent findings were signs of functional overload of the right heart, including a tall R wave with a small S wave in lead V1 in 31 (12.4%) patients, right ventricular myocardial strain in 25 (10.0%), and metabolic changes of the right ventricular myocardium in 20 (8.0%). Repolarization abnormalities included early ventricular repolarization syndrome (10.4%), ST-segment depression (8.8%), and diffuse repolarization disturbances (5.2%). Among conduction abnormalities, intra-atrial block (9.6%), intraventricular conduction disturbances (7.2%), and atrioventricular block (4.8%) predominated. The most common rhythm disorders were ventricular premature beats (8.0%), atrial premature beats (5.2%), ectopic right atrial rhythm (5.6%), and wandering atrial pacemaker (4.4%). Conclusion. Even in children with mild or moderate COVID-19, acute SARS-CoV-2 infection may be accompanied by a wide range of electrocardiographic abnormalities indicating cardiovascular involvement. The most common findings include signs of functional right heart overload, ventricular repolarization abnormalities, and cardiac rhythm and conduction disturbances. These findings support the routine use of electrocardiography during the acute phase of COVID-19 and subsequent follow-up of pediatric patients with identified ECG abnormalities to ensure early detection of potential cardiovascular complications.