title: Heart rate and heart rate variability at rest and during exercise in boys who suffered a severe traumatic brain injury and typically-developed controls.
abstract: OBJECTIVE
  To measure heart rate (HR) and heart rate variability (HRV) at rest and during exercise in children with post-severe traumatic brain injury as compared to age-matched typically-developed controls.
  
  
  METHODS
  Comparative study.
  
  
  METHODS
  Out-patient rehabilitation department.
  
  
  METHODS
  Twelve boys post-severe traumatic brain injury (TBI) (aged 7-13 years) and 18 typically-developed (TD) boys matched for age.
  
  
  METHODS
  HR and HRV were determined at rest and at a steady functional walking rate on the treadmill.
  
  
  METHODS
  HR and HRV parameters include: time domain parameters: standard deviation of the R-R interval, square root of the mean squared differences of successive R-R differences at rest and during steady-state exercise.
  
  
  RESULTS
  Children post-TBI demonstrated higher mean HR values at rest (TBI 91.8 +/- 7.0 beats per minute vs 72.0 +/- 7.1 beats per minute in controls, p < 0.05) and during exercise (TBI 123.4 +/- 15.5 beats per minute vs 113.0 +/- 9.1 beats per minute in controls, p < 0.05). At rest, the time domain measures of HRV were significantly lower in the TBI group (p < 0.05). Time domain mean values decreased significantly during exercise only among the TD children.
  
  
  CONCLUSIONS
  The findings of this study suggest that among children post-severe TBI, the cardiac autonomic mechanism is less efficient at rest and less adaptive to exercise and activity as compared to TD children.
authors.affiliation: Sackler Faculty of Medicine, School of Health Professions, Physical Therapy Department, Tel-Aviv University, Tel Aviv, Israel. michalkz@post.tau.ac.il
authors.forename: Michal
authors.initials: M
authors.lastname: Katz-Leurer
authors.forename: Hemda
authors.initials: H
authors.lastname: Rotem
authors.forename: Ofer
authors.initials: O
authors.lastname: Keren
authors.forename: Shirley
authors.initials: S
authors.lastname: Meyer
mesh_terms: D000293:Adolescent; D001930:Brain Injuries / Q000503:physiopathology* / Q000534:rehabilitation; D002648:Child; D004562:Electrocardiography; D015444:Exercise / Q000502:physiology; D005080:Exercise Test; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D012146:Rest / Q000502:physiology*; D016896:Treatment Outcome