Linear analysis of heart rate variability in post-concussive syndrome

Undersea Hyperb Med. Aug-Sept 2016;43(5):531-547.

Abstract

Heart rate variability (HRV) represents measurable output of coordinated structural and functional systems within the body and brain. Both mild traumatic brain injury (mTBI) and HRV are modulated by changes in autonomic nervous system function. We present baseline HRV results from an ongoing mTBI clinical trial. HRV was assessed via 24-hour ambulatory electrocardiography; recordings were segmented by physiological state (sleep, wakefulness, exercise, standing still). Time, frequency, and spatial domain measures were summarized and compared with symptoms, sleep quality, and neurological examination. Median low frequency/high frequency (LF/HF) ratio exceeded 1.0 across segments, indicating prevalence of sympathetic modulation. Abnormal Sharpened Romberg Test was associated with 29% LF/HF decrease (95% CI [2.1, 47.7], p=0.04); pathological nystagmus associated with decreased standard deviation of electrocardiogram R-R interval (SDNN) index (25% decrease, 95% CI [0.8, 43.4], p=0.04). Increased sympathetic modulation was associated with increased anger scores (19% LF/HF increase with 5-point State Trait Anger Expression Inventory-2 trait anger increase (95% CI [1.2, 39.1], p=0.04)). A 13% HF increase (95% CI [2.1, 25.7], p=0.02) was observed with increased Pittsburgh Sleep Quality Index scores. These results support autonomic nervous system dysfunction in service members after mTBI.

Trial registration: ClinicalTrials.gov Identifier: NCT01611194; https://clinicaltrials.gov/show/NCT01611194.

Keywords: autonomic nervous system; heart rate variability; mild traumatic brain injury; post-concussive syndrome.

Publication types

  • Multicenter Study

MeSH terms

  • Adult
  • Anger
  • Autonomic Nervous System Diseases / complications
  • Autonomic Nervous System Diseases / diagnosis
  • Autonomic Nervous System Diseases / physiopathology*
  • Brain Concussion / complications
  • Brain Concussion / physiopathology
  • Electrocardiography, Ambulatory*
  • Heart Rate / physiology*
  • Humans
  • Linear Models
  • Male
  • Middle Aged
  • Military Personnel*
  • Neurologic Examination / methods
  • Post-Concussion Syndrome / etiology
  • Post-Concussion Syndrome / physiopathology*
  • Randomized Controlled Trials as Topic
  • Sleep / physiology
  • Wakefulness / physiology

Associated data

  • ClinicalTrials.gov/NCT01611194
  • ClinicalTrials.gov/NCT01611194