Date of Award

Summer 2019

Document Type

Open Access Dissertation


Epidemiology and Biostatistics

First Advisor

James B. Burch


Over-modulation of the sympathetic nervous system and reduced heart rate variability (HRV) are commonly overlooked components of pain, poor cognition (decreased attention, recall, and cognitive processing), depression, stress, and fatigue. HRV Biofeedback (HRVB) training induces HRV coherence to balance the autonomic system. Paced breathing (~6 breaths/minute) increases HRV coherence. This randomized, controlled intervention trial tested the hypothesis that HRVB would improve HRV coherence, pain (severity, interference, and catastrophizing), cognitive performance, and reduce depressive, stress, and fatigue symptoms and pain medication use in veterans. Participants were randomized to previously established HRVB or control protocols. Each participant completed a Baseline Assessment, 6 weekly training sessions, a Post-training Assessment, a Booster training session and Assessment (1-month post-training), and a Follow-up Assessment (2-months post-training). Outcomes included: 15- minute resting HRV recordings (HRV Coherence Ratio), Brief Pain Inventory (severity, intensity), Pain Catastrophizing Scale, pain medication use, Paced Auditory Serial Addition Test (PASAT), Hopkins Verbal Learning Test-Revised (HVLT-R), Psychomotor Vigilance Task (PVT), Beck Depression Index-II (BDI-II), Perceived Stress Scale, and Multidimensional Fatigue Inventory. To date, 85 patients completed Baseline Assessment, 63 completed Post-training Assessment, and 50 completed the entire protocol. Patients in the HRVB group had elevated HRV Coherence Ratios at the Follow-up Assessment relative to baseline (0.17±.02 vs. 0.45±0.08, p<0.001), whereas no differences were observed among controls (0.17±0.02 vs. 0.19±0.03, p=0.55). Compared to baseline scores, the Follow-up Assessment resulted in a reduction in Pain Interference scores (5.67 ± 0.19 vs 4.69 ± 0.37 p=<0.01) and an improvement in Mean Reaction Time (431.59 ± 17.32 vs 407.50 ± 17.71, p=0.04). No statistically significant differences were noted among controls. The intervention was received, a statistically significant increase in the HRV Coherence Ratio was observed in the intervention group over time, whereas no changes were seen in the control group. Those in the intervention group improved their reported pain and depression symptoms, reduced non-steroidal anti-inflammatory medication use and reaction time as compared to the control group. Non-pharmacological therapies that improve pain, cognition, and depression would benefit veterans. HRVB is a valid, quantifiable, easilyimplemented intervention. Results from mixed effects statistical models testing study hypotheses indicate the potential benefit of HRVB in this trial.


© 2019, James P. Winstead

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