Heart rate variability as it pertains to sports related concussion and post-concussion syndrome

Abstract

ContextSports related concussions (SRC), occur frequently in contact and collision sports and detection relies predominantly on subjective reports by athletes themselves. A non-invasive means of monitoring brain function and injury is desirable. Existing literature has established autonomic nervous system (ANS) dysfunction in the setting of brain injury. Heart rate variability (HRV) has been accepted as a means of measuring ANS function and correlation of ANS dysregulation after brain injury through HRV measurement can aid in the detection of concussions, monitoring of recovery, and may offer a target for intervention.MethodsThe studies included were found on the Ovid MEDLINE, PubMed, and Google Scholar databases through searches of the following keywords: HRV, heart rate variability and concussion, post-concussion syndrome, and HRV biofeedback. We excluded studies that were not in English and did not meet the inclusion criteria of pertaining to SRC, sports performance, or ANS function.DesignClinical review.ResultsCurrent literature supports the notion that SRC causes dysregulation of the ANS, which can be detecting through changes in HRV. Monitoring HR and analyzing HRV can be used as a tool to detect SRC, monitor recovery, and set a target for treatment. Biofeedback techniques targeting HRV have been used to improve HRV and expedite recovery from SRC.ConclusionExisting literature has shown HRV is a tool for concussion detection and HRV biofeedback can aid in recovery. More rigorous study of the best ways to measure HRV in athletes, qualify and quantify changes in HRV specific to SRC, timing of change, timing of resolution of ANS dysfunction, and clinical significance of persistent HRV change after injury were all identified as targets for future research. Interventional studies evaluating the use of biofeedback as a means of improving HRV and reducing concussion symptoms severity and duration are warranted as well.