ASSESSMENT OF CHANGES IN HEART RATE VARIABILITY INDICES OF STUDENTS AFTER COVID-19 LOCKDOWN: A COHORT STUDY

The objective of this study was to investigate the heart rate variability indicators of students who had contracted COVID-19 after performing physical activity. The aim was to uncover the potential cardiac complications and dysregulations of the autonomic nervous system.

We explored about 11 heart rate variability indicators and their changes immediately after a 5-minute physical activity performed by using Proteus pes 3320 bicycle odometer. Furthermore, we conducted electrocardiographic recording using variational pulsometry. Recording and the analysis of ECG were carried out on a computer using special programs "Cardio reg" and "Cardio prog".

The study revealed that the activity of the heart rhythm regulation indices among students infected by coronavirus was significantly elevated compared to the healthy controls (p<0.05). After the physical activity, the Tension Index, VBI, VRI and LF/HF indicators characterizing the sympathetic tone of HRV regulation were increased, while the coefficient of cardiointervals variation decreased among infected group students. Moreover, the ECG recording showed that after physical activity, the disturbances of cardiac functioning changed, accompanied by tachycardia.

The findings of this study demonstrate that short-term physical activity contributed to the transition of cardiovascular system indicators from the adaptive stress zone to the tense zone, which is likely due to the negative impact of COVID-19 on the capabilities of both the cardiovascular and nervous systems. Therefore, this study contributes to a deeper understanding of changes in HRV in the context of post-COVID-19 cardiovascular dysfunction among young adults.