Dolphin
Senior Member (Voting Rights)
[This looks like a pre-print of some sort]
Association Between Vagal Tone and Functional Recovery in Post-Viral Fatigue Syndrome Following COVID-19
Pranav Bhanushali
Abstract
Background:
The global COVID-19 pandemic has led to a significant burden of persistent symptoms, notably Post-Viral Fatigue Syndrome (PVFS), characterized by debilitating fatigue, post-exertional malaise, and cognitive dysfunction, severely impacting quality of life and functional capacity. Emerging evidence suggests that autonomic nervous system (ANS) dysfunction, particularly impaired vagal tone, may contribute to the pathophysiology of chronic fatigue states. Understanding the relationship between vagal tone and recovery trajectories is crucial for developing targeted interventions.
Purpose:
This study aimed to investigate the association between baseline vagal tone, assessed through Heart Rate Variability (HRV), and the subsequent trajectory and extent of functional recovery in individuals diagnosed with PVFS following COVID-19 infection. Methods: A prospective cohort study was conducted with [N] participants aged [X-Y] years who had confirmed COVID-19 infection at least 3 months prior and presented with persistent PVFS symptoms. Baseline vagal tone was non-invasively measured using resting HRV parameters (e.g., Root Mean Square of Successive Differences (RMSSD), High Frequency (HF) power). Functional recovery was assessed at baseline, 3, and 6 months using validated self-report measures for fatigue severity (e.g., Fatigue Severity Scale), health-related quality of life (e.g., SF-36), and objective functional tests (e.g., 6-minute walk test). Statistical analyses included correlation and longitudinal regression models to examine the association between baseline HRV and changes in functional outcomes over time, controlling for relevant confounders.
Results:
Our findings revealed a significant positive association between higher baseline vagal tone and a more favorable functional recovery trajectory. Specifically, participants with higher baseline RMSSD values exhibited significantly greater reductions in fatigue severity (p<0.01) and improved physical and mental health component scores on the SF-36 (p<0.05) at both 3 and 6 months post-baseline, independent of initial symptom severity. Conversely, consistently lower vagal tone was associated with prolonged fatigue and poorer functional outcomes.
Conclusion:
This study demonstrates a significant association between baseline vagal tone and functional recovery in individuals experiencing Post-Viral Fatigue Syndrome after COVID-19. These findings highlight vagal tone as a potential prognostic biomarker and suggest that interventions aimed at enhancing parasympathetic activity may represent a promising therapeutic avenue to improve functional outcomes and quality of life for this patient population.
Keywords: Vagal Tone; Heart Rate Variability; Post-Viral Fatigue Syndrome; Long COVID; Functional Recovery; Autonomic Dysfunction; COVID-19.
Association Between Vagal Tone and Functional Recovery in Post-Viral Fatigue Syndrome Following COVID-19
Pranav Bhanushali
Abstract
Background:
The global COVID-19 pandemic has led to a significant burden of persistent symptoms, notably Post-Viral Fatigue Syndrome (PVFS), characterized by debilitating fatigue, post-exertional malaise, and cognitive dysfunction, severely impacting quality of life and functional capacity. Emerging evidence suggests that autonomic nervous system (ANS) dysfunction, particularly impaired vagal tone, may contribute to the pathophysiology of chronic fatigue states. Understanding the relationship between vagal tone and recovery trajectories is crucial for developing targeted interventions.
Purpose:
This study aimed to investigate the association between baseline vagal tone, assessed through Heart Rate Variability (HRV), and the subsequent trajectory and extent of functional recovery in individuals diagnosed with PVFS following COVID-19 infection. Methods: A prospective cohort study was conducted with [N] participants aged [X-Y] years who had confirmed COVID-19 infection at least 3 months prior and presented with persistent PVFS symptoms. Baseline vagal tone was non-invasively measured using resting HRV parameters (e.g., Root Mean Square of Successive Differences (RMSSD), High Frequency (HF) power). Functional recovery was assessed at baseline, 3, and 6 months using validated self-report measures for fatigue severity (e.g., Fatigue Severity Scale), health-related quality of life (e.g., SF-36), and objective functional tests (e.g., 6-minute walk test). Statistical analyses included correlation and longitudinal regression models to examine the association between baseline HRV and changes in functional outcomes over time, controlling for relevant confounders.
Results:
Our findings revealed a significant positive association between higher baseline vagal tone and a more favorable functional recovery trajectory. Specifically, participants with higher baseline RMSSD values exhibited significantly greater reductions in fatigue severity (p<0.01) and improved physical and mental health component scores on the SF-36 (p<0.05) at both 3 and 6 months post-baseline, independent of initial symptom severity. Conversely, consistently lower vagal tone was associated with prolonged fatigue and poorer functional outcomes.
Conclusion:
This study demonstrates a significant association between baseline vagal tone and functional recovery in individuals experiencing Post-Viral Fatigue Syndrome after COVID-19. These findings highlight vagal tone as a potential prognostic biomarker and suggest that interventions aimed at enhancing parasympathetic activity may represent a promising therapeutic avenue to improve functional outcomes and quality of life for this patient population.
Keywords: Vagal Tone; Heart Rate Variability; Post-Viral Fatigue Syndrome; Long COVID; Functional Recovery; Autonomic Dysfunction; COVID-19.