Non-pharmacological Intervention for Chronic Pain in Veterans: A Pilot Study of Heart Rate Variability Biofeedback

Abstract

Objective:Chronic pain is an emotionally and physically debilitating form of pain that activates the body's stress response and over time can result in lowered heart rate variability (HRV) power, which is associated with reduced resiliency and lower self-regulatory capacity. This pilot project was intended to determine the effectiveness of HRV coherence biofeedback (HRVCB) as a pain and stress management intervention for veterans with chronic pain and to estimate the effect sizes. It was hypothesized that HRVCB will increase parasympathetic activity resulting in higher HRV coherence measured as power and decrease self-reported pain symptoms in chronic pain patients.Study design:Fourteen veterans receiving treatment for chronic pain were enrolled in the pre-post intervention study. They were randomly assigned, with 8 subjects enrolled in the treatment group and 6 in the control group. The treatment group received biofeedback intervention plus standard care, and the other group received standard care only. The treatment group received four HRVCB training sessions as the intervention.Measures:Pre-post measurements of HRV amplitude, HRV power spectrum variables, cardiac coherence, and self-ratings of perceived pain, stress, negative emotions, and physical activity limitation were made for both treatment and control groups.Results:The mean pain severity for all subjects at baseline, using the self-scored Brief Pain Inventory (BPI), was 26.71 (SD=4.46; range=21–35) indicating a moderate to severe perceived pain level across the study subjects. There was no significant difference between the treatment and control groups at baseline on any of the measures. Post-HRVCB, the treatment group was significantly higher on coherence (P=.01) and lower (P=.02) on pain ratings than the control group. The treatment group showed marked and statistically significant (1-tailed) increases over the baseline in coherence ratio (191%, P=.04) and marked, significant (1-tailed) reduction in pain ratings (36%, P<.001), stress perception (16%, P=.02), negative emotions (49%, P<.001), and physical activity limitation (42%, P<.001). Significant between-group effects on all measures were found when pre-training values were used as covariates.Conclusions:HRVCB intervention was effective in increasing HRV coherence measured as power in the upper range of the LF band and reduced perceived pain, stress, negative emotions, and physical activity limitation in veterans suffering from chronic pain. HRVCB shows promise as an effective non-pharmacological intervention to support standard treatments for chronic pain.

Targeting the Autonomic Nervous System Balance in Patients with Chronic Low Back Pain using Transcranial Alternating Current Stimulation: A Randomized, Crossover, Double-Blind, Placebo-Controlled Pilot Study

“…To derive the other HRV frequency components (LF, and LF/HF), the IBI event series was resampled at 2 Hz to generate an equally spaced intervals time series. RSA and LF were calculated based on the Porges-Bohrer method (53,54); RSA uses a third-order, 21 These variables included:1) respiratory sinus arrhythmia (i.e., RSA or high frequency HRV defined by the frequencies of spontaneous breathing (.12-.4 Hz), 2) low frequency HRV (i.e., occurring within the frequencies of spontaneous vasomotor and blood pressure oscillations; .06-.10 Hz), and 3) ratio of LF and HF (LF/HF)…”

“…These chronic systemic functional problems are reflected in the regulation of the heart by the most rapidly responsive component of the nervous system, the ventral vagal complex, as measured by RSA (19). Previous studies have targeted the reduced RSA using biofeedback interventions, and HRV components have been used to measure the efficacy of chronic pain therapies (21)(22)(23)(24). Yet, little is known if targeting network pathologies by non-invasive brain stimulation can influence ANS balance in patients with CLBP.…”

Psychological Interventions for the Management of Chronic Pain: a Review of Current Evidence

“…Among recent studies of biofeedback and pain, Berry et al utilized heart rate variability training with veterans who were receiving treatment for chronic pain [27]. They found that after four biofeedback sessions, the treatment group members averaged statistically significant reductions in perceived pain, stress, negative emotions, and physical activity limitations.…”

The potential role of behavioral therapies in the management of centrally mediated abdominal pain

“…Efficacy of biofeedback has been demonstrated in headaches, fibromyalgia, temporomandibular disorders, and other chronic pain states . The application of biofeedback in gastrointestinal disorders is predominantly within dyssynergic defecation, fecal incontinence, and appears promising for functional anorectal pain .…”