Clinical and Functional Characteristics of Cardiovascular System in Children Who Have Undergone COVID-19

Abstract

Background: The involvement of various functional systems in the pathological process of COVID-19 has been extensively studied. Nevertheless, significant uncertainties persist regarding the effects on various organs and systems in children. Recent literature reviews underscore the polymorphic nature of extrapulmonary clinical manifestations, with cardiovascular disorders being the most prevalent. Objectives: The aim of the research is to study the clinical and functional state of the cardiovascular system in children with a history of COVID-19. Methods: The research was carried out in three stages: Stage 1 – a retrospective study of 400 pediatric medical records with PCR-confirmed COVID-19. The age range of the patients is 1 - 18 years, who were undergoing inpatient treatment in the Regional Infectious Diseases Hospital of Aktobe, Kazakhstan, from October to December 2020. Stage 2 involved clinical, laboratory, and instrumental cardiovascular assessments 24 - 36 months post-infection. Stage 3 included an in-depth evaluation of 40 children with abnormalities identified in stage 2 [persistent cardiovascular symptoms, electrocardiogram (ECG), and blood pressure (BP) issues]. Follow-ups, conducted in 2023 - 2024, used strict selection, standardized methods, and independent interpretation; social factors were omitted. The obtained data were processed using IBM SPSS, version 25. Descriptive statistics were used to characterize clinical variables. Normality was assessed with the Shapiro-Wilk test; group differences with the Mann-Whitney U test. Results were considered statistically significant at P < 0.05 and P < 0.001. Results: The retrospective study revealed a notable gender imbalance with boys predominating. The clinical course was predominantly mild-to-moderate; a severe course was documented in 6.5% of cases. According to ECG interpretation, P wave and QT interval changes were observed in the acute period of COVID-19. A prospective laboratory and instrumental examination identified increased immunoglobulin G (IgG) levels in all age groups and long-term changes in ECG. The group of school-age children with cardiac complaints suffered from insufficient BP reduction at night. They also exhibited various heart rhythm disorders (35%). Conclusions: Significant cardiac changes in adolescents post-COVID-19 indicate the risk of cardiovascular complications and the need for long-term follow-up. The findings warrant further investigation, especially with regard to cardiovascular and immune changes and their long-term consequences in children who have undergone COVID-19.