Sports Medicine Research: In the Lab & In the Field: Medical Professionals Could Measure the Athlete’s Change of Heart Following A Concussion (Sports Med Res)


Wednesday, June 7, 2017

Medical Professionals Could Measure the Athlete’s Change of Heart Following A Concussion

Heart rate variability of athletes across concussion recovery milestones: A preliminary study

Senthinathan A, Mainwaring L, Hutchison M. Clin J Sport Med. 2017; 27(3):288-295

Take Home Message: Athletes that sustained a concussion displayed altered heart rate variability measures compared with controls, and those with a history of concussion had more disturbances in heat rate variability measures.

Concussions can affect numerous physiological processes including those in the cardiovascular system (via the autonomic nervous system). Medical professionals can measure heart rate variability as a noninvasive, objective measure to assess the influence of concussions on the heart and to assist with return-to-play decisions. However, heart rate variability, which has been explored for severe brain injury, has been understudied with respect to sport concussion. Therefore, the authors evaluated heart rate variability among 11 athletes that sustained a concussion and 11 healthy sex- and sport-matched controls. They tested the athletes at 3 phases during an athlete’s concussion recovery: (1) within 1-week after injury (the symptomatic phase), (2) after resolution of symptoms (progressing to exercise in return-to-play progression), and (3) 1-week after medical clearance to return to play. During each session, participants completed the Rivermead Post-Concussion Symptoms Questionnaire and physicians measured the participant’s heart rate variability with heart rate monitors during three 5-minute intervals: twice when the participant was sitting and once when standing, which provided a measurement during a change in state and effort. The authors found no relationship between heart rate variability measures and concussion symptoms nor days taken to return to play. However, the authors found a relationship between concussion history and physiological function of the heart where those with a greater number of previous concussions had greater physiologic disturbances and increased sympathetic and decreased parasympathetic activation while sitting. The authors also detected that several measures of heart rate variability were different between groups over time. Typically, the two groups were different during the symptomatic phase (2-7 days post injury). However, the controls didn’t change much over time but the athletes with a concussion had heart rate variability changes that made their variability more like the control athletes by one week after return to play.

The authors found that an athlete with a concussion is likely to have altered heart rate variability when compared with a control athlete. The authors also suggested that heart rate variability was related to increased frequency of previous concussions.  It is interesting to note that such most of the heart rate variability findings were noted in the sitting position, and not in the standing position. However, further investigation is necessary to determine if this is still true after controlling for concussion history, which was found to be associated with heart rate variability. On the other hand, the authors also found a small change in heart rate variability measures in the control group, which could be attributed to other physiological and psychological stressors (exams, relationships, work). Future studies should incorporate baseline heart rate variability testing, while also assessing and accounting for other physiological and psychological stresses that could be going on during a baseline testing session. At this time, medical professionals should be aware of the impact of concussion and concussion history on the heart, and continue to educate athletes on the risks concussions pose on themselves if they do not report a possible concussion injury (e.g., heart rate variability, greater risk of lower extremity injury).

Question for Discussion: Do you monitor heart rate variability following injuries? Could you implement heart rate monitors during preseason baseline testing? Would you consider adding this to your concussion assessment and return to play protocol?

Written by: Jane McDevitt, PhD
Reviewed by: Jeff Driban

Related Posts:

Senthinathan A, Mainwaring LM, & Hutchison M (2017). Heart Rate Variability of Athletes Across Concussion Recovery Milestones: A Preliminary Study. Clinical Journal of Sport Medicine, 27 (3), 288-295 PMID: 27379659


maggie lynch said...

This is a very interesting study. Looking at heart rate variability is a novel way of assessing concussion that would not take a substantial amount of time or effort to implement into concussion protocol. Especially in the era of fit bits, monitoring heart rate is easier than ever for athletes. Educating athletes on this physiologic change could also decrease the amount of unreported concussions. I would be interested to see if these results remain with a larger sample, but I'm excited to see where this research goes! Thanks for sharing your results.

Juliana Jimenez said...

I have never thought about monitoring heart rate variability post concussions but it makes complete sense that the heart rate could be effected after a brain injury. I thought the method was good with tracking heart rate at three different points during concussion recovery. I am curious though why they did not narrow the window for the first measurement to be 1-2 days post concussion, rather than within 1 week. I have seen a good amount of athletes symptom free within the first week of receiving a concussion and beginning their return to play progression. I like how the authors stated that other stressors could also be causing the heart rate variability. I also thought that the athlete's hydration levels could influence this too. It will be interesting to see where future research goes with this. At my old clinical placement all of the athletes wore heart rate monitors during practices. It would be cool to see the data from those monitors, if the athlete were to keep them on following a suspected concussion and see if heart rate changes abnormally for that athlete in the early phase.

Adrienne Dembeck said...

I found this study very interesting, because I haven't thought much about the connection between heart rate and concussion. Juli and Maggie made great points, I also agree that a measurement taken 2 days post injury might show some interesting results that could differ from those taken a week post injury. To touch upon the discussion question, depending on the injury and how traumatic it was, I don't think that we monitor heart rate after injuries enough (at least in the clinical settings that I have been in). We usually think about using heart rate and other vital sign s during emergency situations, when really they matter more often than that. I think that based on the results of the study, heart rate monitors used for baseline testing would be very beneficial, especially when there might be some gray area for a specific individual with return to play and return to learn protocols. Having heart rate as a measurement tool would be helpful since concussions are such subjective injuries, it would allow the clinician to objectively have a better understanding of where the patient is in their recovery. I think there is a lot we can learn from measuring heart rate and other vital signs, I think that studies like this have a promising future.

Jane McDevitt said...

Juliana & Adrienne,

I agree I would like to see the variability more acute and how it changes long term. I would have to imagine that they probably tried to get the athlete as acute as possible, and within a week was the mean time they were able to measure the HR variability post injury. I also think you both brought up a good point about measuring vitals over all. I think urinalysis, heart rate, respiratory rate would be interesting to follow and see if that has any association to concussion recovery or concussion symptomatology. We measure vitals with many other injuries but we typically do not measure them with sports injury; however, as this study points out our body is connected and the brain is in control so it seems feasible that tracking the athlete's vitals could provide helpful information in his/her concussion recovery.

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