Cardiovascular disorders in children who had COVID-19 infection in outpatient settings

Aim - to study the state of the cardiovascular system (CVS) in children after SARS-CoV-2 infection. Materials and methods. The study group was completed by 70 children of 7-14 years old without chronic pathology who were asymptomatic, mild or moderate in the course of COVID-19 infection and who had laboratory confirmation of the disease. The comparison group consisted of 30 children aged 7-14 years who had no COVID-19 infection. The state of the CVS was assessed by electrocardiography (ECG) at the rest and after exercise. Structural abnormalities and cardiovascular dysfunction were assessed by echocardiography (EchoCG). Statistical processing of the obtained data was performed with the application package "Statistica 10.0 for Windows" by the method of variation statistics. Results. Heart rhythm (HR), conductivity and excitability functions disorders were detected in 38.6% (27 children). Heart deterioration of repolarization processes (as the metabolic disorders) was noted in 11.4% (8 children). More than half of the children had a combination of these disorders. The results of the assessment of the CVS response to exercise revealed a hypoergic reaction in 42.8% (30 children) in the form of an increasing of HR in the range of 0-19%, which indicates an insufficient response of the CVS to exercise. In 24.3% (17 children) was noted hyperergic reaction in the form of an increasing heart rate by 40-80%. And only 32.9% (23 children) had a normal reaction of the CVS to physical activity with an increasing heart rate by 20-30%. In the comparison group, the following was noted: normal reaction in 70.0% (21 children), hypoergic type of CVS reaction in 20.0% (6 children) and hyperergic type in 10.0% (3 children). Conclusions. The COVID-19 infection leads to a deterioration in the CVS response. In the majority of pediatric patients, cardiovascular lesions after SARS-CoV-2 manifest as subclinical changes that are detected during instrumental investigations. The use of non-invasive methods such as ECG and EchoCG help to diagnose cardiovascular lesions, as well as to identify changes in the CVS that may have important prognostic significance for the unfavorable course of the disease in children with SARS-CoV-2 infection. In this regard, it is necessary to introduce mandatory ECG in children before and after exercise testing for early detection of cardiovascular disorders in the practice of pediatricians and general practitioners. If necessary, the use of EchoCG and Holter monitoring of blood pressure and ECG is justified. The research was carried out in accordance with the principles of the Declaration of Helsinki. Informed consent of the child and child's parents was obtained for the research. The authors declare no conflict of interest.