ABSTRACT
Purpose
: To systematically regroup articles that were published since the latest systematic search, but with specific inclusion criteria to help comparison that will offer a focused presentation of methods and results. This will offer a full overview of HRV’s behavior at rest and during exercise in adults post-concussion.
Methods
: The systematic review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) method. A computer-based systematic search was conducted in December 2019 through the Pubmed, Scopus and SPORTDiscus databases. A manual search was performed through the reference list of all articles retained. The reliability of the systematic search was assured by having the article selection process entirely repeated by a second author.
Results
: The systematic search yielded a total of 15 articles to be further analyzed. Results show impairment of HRV during exercise for individuals with concussion, heterogenous studies with lack of control over confounding factors and only less than half of the results showing a significant difference between individuals with concussion and controls.
Conclusion
: Further research should try standardizing HRV measurement protocols that control confounding factors to allow easier comparison between studies and allows the possibility for an eventual meta-analysis.
List of abbreviations
MTBI: Mild Traumatic Brain Injury
HRV: Heart Rate Variability
LF: Low Frequency Power
HF: High Frequency Power
RMSSD: Root Mean Square of Successive Differences
CVRR: Coefficient of Variation of the RR Intervals
SDRR: Standard Deviation of the RR Intervals
SampEn: Sample Entropy
IHGT: Isometric Hand Grip Test
Aknowledgement
Authors would like to thank all researchers referenced in this study, as well as all scientific investigations that were read, but unfortunately not included.
Declaration of interest
This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. The authors certify that there is no conflict of interest with any financial organization regarding the material discussed in the manuscript.