The effect of biofeedback on function in patients with heart failure

Heart rate variability biofeedback enhances cognitive, motor, psychological, and autonomic functions in post-stroke rehabilitation

Post-stroke patients often experience psychological distress and autonomic nervous system (ANS) dysregulation, impacting their well-being. This study evaluated the effectiveness of heart rate variability (HRV) biofeedback on cognitive, motor, psychological, and ANS functions in sixty-two ischemic stroke patients (43 males, mean age = 60.1) at a Medical Center in southern Taiwan. To prevent interaction, we allocated patients to the HRV biofeedback or control (usual care) group based on their assigned rehabilitation days, with 31 patients in each group. Assessments conducted at baseline, three, and six months included the Montreal Cognitive Assessment (MoCA), Fugl-Meyer Assessment for Upper Extremities (FMA-UE), Perceived Stress Scale, Hospital Anxiety and Depression Scales (HADS), and HRV indices. Mixed-effect models were used to analyze Group by Time interactions. The results revealed significant interactions across all functions. At 3 months, significant improvements in the HRV biofeedback group were observed only in MoCA, FMA-UE, and HADS-depression scores compared to the control group. By 6 months, all measured outcomes demonstrated significant improvements in the biofeedback group relative to the control group. These results suggest that HRV biofeedback may be an effective complementary intervention in post-stroke rehabilitation, warranting further validation.

Effects of stress management interventions on heart rate variability in adults with cardiovascular disease: a systematic review and meta-analysis

Meta-analysis was used to investigate the potential benefits of stress management interventions (SMIs) on vagally-mediated heart rate variability (HRV) in adults with cardiovascular disease. Electronic bibliographic databases were searched through August 2022. Randomized controlled trials and quasi-experimental studies assessing effects of SMIs on HRV were included. Methodological quality was assessed with a standardized checklist. A pooled effect size was calculated for vagally-mediated HRV indices (standard deviation of normal-to-normal intervals, root mean square of the successive differences, and high frequency power) using random effects models. Fourteen studies (1202 participants, Mage: 59 ± 6.25 years; 25% ± 16% women; 61% ± 22% White) were included. Ten studies (11 effects) reported short-term HRV assessment; a small between-group difference emerged for vagally-mediated HRV (d+ = .27, 95% confidence interval [CI] 0.01-0.52, k = 11). Most interventions examined biofeedback; these studies yielded a small between-group difference on vagally-mediated HRV (d+ = 0.31, 95% CI 0.09-0.53, k = 7, Q [6] = 3.82, p = .70, I2 = 11%). This is the first systematic examination of the effect of SMIs on HRV in adults with CVD. Findings suggest a small effect of SMIs on vagally-mediated HRV, with biofeedback likely driving the effect. More research is required to fully understand whether this benefit on vagally-mediated HRV applies to other SMIs.

Multimodal non-invasive non-pharmacological therapies for chronic pain: mechanisms and progress

BACKGROUND

Chronic pain conditions impose significant burdens worldwide. Pharmacological treatments like opioids have limitations. Non-invasive non-pharmacological therapies (NINPT) encompass diverse interventions including physical, psychological, complementary and alternative approaches, and other innovative techniques that provide analgesic options for chronic pain without medications.

MAIN BODY

This review elucidates the mechanisms of major NINPT modalities and synthesizes evidence for their clinical potential across chronic pain populations. NINPT leverages peripheral, spinal, and supraspinal mechanisms to restore normal pain processing and limit central sensitization. However, heterogeneity in treatment protocols and individual responses warrants optimization through precision medicine approaches.

CONCLUSION

Future adoption of NINPT requires addressing limitations in standardization and accessibility as well as synergistic combination with emerging therapies. Overall, this review highlights the promise of NINPT as a valuable complementary option ready for integration into contemporary pain medicine paradigms to improve patient care and outcomes.

Assessment and Therapeutic Modulation of Heart Rate Variability: Potential Implications in Patients with COVID-19

Cardiac damage has been attributed to SARS-CoV-2-related pathology contributing to increased risk of vascular events. Heart rate variability (HRV) is a parameter of functional neurocardiac integrity with low HRV constituting an independent predictor of cardiovascular mortality. Whether structural cardiac damage translates into neurocardiac dysfunction in patients infected with SARS-CoV-2 remains poorly understood. Hypothesized mechanisms of possible neurocardiac dysfunction in COVID-19 comprise direct systemic neuroinvasion of autonomic control centers, ascending virus propagation along cranial nerves and cardiac autonomic neuropathy. While the relationship between the autonomic nervous system and the cytokine cascade in general has been studied extensively, the interplay between the inflammatory response caused by SARS-CoV-2 and autonomic cardiovascular regulation remains largely unclear. We reviewed the current literature on the potential diagnostic and prognostic value of autonomic neurocardiac function assessment via analysis of HRV including time domain and spectral analysis techniques in patients with COVID-19. Furthermore, we discuss potential therapeutic targets of modulating neurocardiac function in this high-risk population including HRV biofeedback and the impact of long COVID on HRV as well as the approaches of clinical management. These topics might be of particular interest with respect to multimodal pandemic preparedness concepts.

Heart Rate Variability: A Measure of Cardiovascular Health and Possible Therapeutic Target in Dysautonomic Mental and Neurological Disorders

Mental illness such as depression and anxiety as well as cerebrovascular disease are linked to impairment of neurocardiac function mediated by changes to the autonomic nervous system with increased sympathetic and decreased parasympathetic activity. Autonomic neurocardiac function can be evaluated by computing heart rate variability (HRV). Over the past decades, research has demonstrated the diagnostic value of HRV as independent predictor of cardiovascular mortality and as disease marker in progressive autonomic nervous system disorders such as Parkinson’s disease. Here we summarize our studies on HRV and its therapeutic modulation in the context of psychopharmacology as well as psychiatric and neurological disorders to honor the life of Professor Evgeny Vaschillo, the true pioneer of HRV research who sadly passed away on November 21st, 2020.

The Effect of Heart Rate Variability Biofeedback Training on Vagal Tone in Athletically Talented Secondary School Students

This study examines whether twelve sessions of heart rate variability biofeedback training would improve vagally mediated heart rate variability. If so, it would go some way in explaining why breathing-based interventions reduce clinical symptoms and improve non-clinical performance outcomes. Methods: Thirty participants (N = 30, Nfemale = 13) aged 14–13-year-old, all talented athletes, from a sport specialist school in SE London UK, were randomly divided into three groups, a control group, a psychology skills training combined with heart rate variability biofeedback training group, and a heart rate variability biofeedback only group. For the combined group, a variety of typical psychological skill training techniques were also used. Results: Paired participant t-test and the Wilcoxon Signed Rank test found non-significant differences between pre- and post-intervention measurements of heart rate variability. Non-significant results remained even after pooling the biofeedback training groups (n = 19). Conclusions: Our results do not indicate that beneficial effects associated with focused breathing training can be attributed to improved vagal tone. Further investigation into the underlying mechanisms of the benefits of focused breathing techniques is necessary to maximize clinical and non-clinical outcomes.

Psychosocial Interventions for Patients With Heart Failure and Their Impact on Depression, Anxiety, Quality of Life, Morbidity, and Mortality: A Systematic Review and Meta-Analysis

OBJECTIVE

The purpose of this systematic review and meta-analysis was to evaluate the ability of psychosocial interventions to reduce depression and anxiety, improve quality of life, and reduce hospitalization and mortality rates in patients with heart failure.

METHODS

Studies of psychosocial interventions published from 1970 to 2021 were identified through four databases (PubMed, Ovid MEDLINE, PsycINFO, Cochrane). Two authors independently conducted a focused analysis and reached a final consensus on the studies to include, followed by a quality check by a third author. A risk of bias assessment was conducted.

RESULTS

Twenty-three studies were identified, but only 15 studies of mostly randomized controlled trials with a total of 1370 patients with heart failure were included in the meta-analysis. Interventions were either cognitive behavioral therapy (CBT) or stress management. The pooled intervention effect was in favor of the intervention for depression (combined difference in standardized mean change [DSMC]: -0.41; 95% confidence interval [CI] = -0.66 to -0.17; p = .001) and anxiety (combined DSMC: -0.33; 95% CI = -0.51 to -0.15; p < .001) but was only a trend for quality of life (combined DSMC: 0.14; 95% CI = -0.00 to 0.29; p = .053). Evidence was limited that interventions produced lower rates of hospitalization (5 of 5 studies showing a beneficial effect) or death (1 of 5 with a beneficial effect).

CONCLUSIONS

CBT and stress management interventions significantly reduced depression and anxiety compared with control conditions. CBT significantly improved quality of life compared with controls, but stress management did not. Longer treatment duration seemed to be an important factor related to treatment success.

Efficacy of bio- and neurofeedback for depression: a meta-analysis

BACKGROUND

For many years, biofeedback and neurofeedback have been implemented in the treatment of depression. However, the effectiveness of these techniques on depressive symptomatology is still controversial. Hence, we conducted a meta-analysis of studies extracted from PubMed, Scopus, Web of Science and Embase.

METHODS

Two different strings were considered for each of the two objectives of the study: A first group comprising studies patients with major depressive disorder (MDD) and a second group including studies targeting depressive symptomatology reduction in other mental or medical conditions.

RESULTS

In the first group of studies including patients with MDD, the within-group analyses yielded an effect size of Hedges' g = 0.717, while the between-group analysis an effect size of Hedges' g = 1.050. Moderator analyses indicate that treatment efficacy is only significant when accounting for experimental design, in favor of randomized controlled trials (RCTs) in comparison to non RCTs, whereas the type of neurofeedback, trial design, year of publication, number of sessions, age, sex and quality of study did not influence treatment efficacy. In the second group of studies, a small but significant effect between groups was found (Hedges' g = 0.303) in favor of bio- and neurofeedback against control groups. Moderator analyses revealed that treatment efficacy was not moderated by any of the sociodemographic and clinical variables.

CONCLUSIONS

Heart rate variability (HRV) biofeedback and neurofeedback are associated with a reduction in self-reported depression. Despite the fact that the field has still a large room for improvement in terms of research quality, the results presented in this study suggests that both modalities may become relevant complementary strategies for the treatment of MDD and depressive symptomatology in the coming years.

Influencing Cardiovascular Outcomes through Heart Rate Variability Modulation: A Systematic Review

Psychological stress is a well-established risk factor for cardiovascular disease (CVD). Heart rate variability (HRV)-biofeedback could significantly reduce stress levels and improve autonomic nervous system function and cardiovascular endpoints. We aimed to systematically review the literature to investigate the impact of HRV modulation through HRV-biofeedback on clinical outcomes in patients with CVD. A literature search was performed in the following databases: MEDLINE (PubMed), Embase, and Cochrane from the inception until 1 October 2021. Patients in the HRV-biofeedback group had significantly lower rates of all-cause readmissions than patients who received psychological education (respectively, p = 0.028 and p = 0.001). Heart failure following HRV-biofeedback displayed an inverse association with stress and depression (respectively, p = 0.022 and p = 0.033). When stratified according to left ventricular ejection fraction (LVEF), patients with LVEF ≥ 31% showed improved values of the 6 min walk test after HRV-biofeedback interventions (p = 0.05). A reduction in systolic and diastolic blood pressure associated with HRV-biofeedback was observed (p < 0.01) in pre-hypertensive patients. HRV-biofeedback had beneficial effects on different cardiovascular diseases documented in clinical trials, such as arterial hypertension, heart failure, and coronary artery disease. A standard breathing protocol should be applied in future studies to obtain equivalent results and outcomes. However, data regarding mortality in patients with coronary artery disease are scarce and need further research.

Targeting autonomic flexibility to enhance cognitive training outcomes in older adults with mild cognitive impairment: study protocol for a randomized controlled trial

Importance

Cognitive training with components that can further enhance the transferred and long-term effects and slow the progress of dementia is needed for preventing dementia.

Objective

The goal of the study is to test whether improving autonomic nervous system (ANS) flexibility via a resonance frequency breathing (RFB) training will strengthen the effects of a visual speed of processing (VSOP) cognitive training on cognitive and brain function, and slow the progress of dementia in older adults with mild cognitive impairment (MCI).

Design

Stage II double-blinded randomized controlled trial. The study was prospectively registered at ClinicalTrials.gov, with registration approved on 21 August 2020 (No. NCT04522791).

Setting

Study-related appointments will be conducted on-site at University of Rochester Medical Center locations. Data collection will be conducted from August 2020 to February 2025.

Participants

Older adults with MCI (n = 114) will be randomly assigned to an 8-week combined intervention (RFB+VSOP), VSOP with guided imagery relaxation (IR) control, and a IR-only control, with periodical booster training sessions at follow-ups. Mechanistic and distal outcomes include ANS flexibility, measured by heart rate variability, and multiple markers of dementia progress. Data will be collected across a 14-month period.

Discussion

This will be among the first RCTs to examine in older persons with MCI a novel, combined intervention targeting ANS flexibility, an important contributor to overall environmental adaptation, with an ultimate goal for slowing neurodegeneration.

Trial registration

ClinicalTrials.gov NCT04522791. Registered on 21 August 2020

Protocol version: STUDY00004727; IRB protocol version 2, approved on 30 July 2020.

Heart Rate Variability Biofeedback Improves Emotional and Physical Health and Performance: A Systematic Review and Meta Analysis

We performed a systematic and meta analytic review of heart rate variability biofeedback (HRVB) for various symptoms and human functioning. We analyzed all problems addressed by HRVB and all outcome measures in all studies, whether or not relevant to the studied population, among randomly controlled studies. Targets included various biological and psychological problems and issues with athletic, cognitive, and artistic performance. Our initial review yielded 1868 papers, from which 58 met inclusion criteria. A significant small to moderate effect size was found favoring HRVB, which does not differ from that of other effective treatments. With a small number of studies for each, HRVB has the largest effect sizes for anxiety, depression, anger and athletic/artistic performance and the smallest effect sizes on PTSD, sleep and quality of life. We found no significant differences for number of treatment sessions or weeks between pretest and post-test, whether the outcome measure was targeted to the population, or year of publication. Effect sizes are larger in comparison to inactive than active control conditions although significant for both. HRVB improves symptoms and functioning in many areas, both in the normal and pathological ranges. It appears useful as a complementary treatment. Further research is needed to confirm its efficacy for particular applications.

Heart rate variability biofeedback in chronic disease management: A systematic review

BACKGROUND

Heart rate variability biofeedback (HRVB) is a non-pharmacological intervention used in the management of chronic diseases.

METHOD

A systematic search was performed according to eligibility criteria including adult chronic patients, HRVB as main treatment with or without control conditions, and psychophysiological outcomes as dependent variables.

RESULTS

In total, 29 articles were included. Reported results showed the feasibility of HRVB in chronic patients without adverse effects. Significant positive effects were found in various patient profiles on hypertension and cardiovascular prognosis, inflammatory state, asthma disorders, depression and anxiety, sleep disturbances, cognitive performance and pain, which could be associated with improved quality of life. Improvements in clinical outcomes co-occurred with improvements in heart rate variability, suggesting possible regulatory effect of HRVB on autonomic function.

CONCLUSIONS

HRVB could be effective in managing patients with chronic diseases. Further investigations are required to confirm these results and recommend the most effective method.

A meta-analysis on heart rate variability biofeedback and depressive symptoms

Heart rate variability biofeedback (HRVB) has been used for a number of years to treat depressive symptoms, a common mental health issue, which is often comorbid with other psychopathological and medical conditions. The aim of the present meta-analysis is to test whether and to what extent HRVB is effective in reducing depressive symptoms in adult patients. We conducted a literature search on Pubmed, ProQuest, Ovid PsycInfo, and Embase up to October 2020, and identified 721 studies. Fourteen studies were included in the meta-analysis. Three meta-regressions were also performed to further test whether publication year, the questionnaire used to assess depressive symptoms, or the interval of time between T0 and T1 moderated the effect of HRVB. Overall, we analysed 14 RCTs with a total of 794 participants. The random effect analysis yielded a medium mean effect size g = 0.38 [95% CI = 0.16, 0.60; 95% PI =  - 0.19, 0.96], z = 3.44, p = 0.0006. The total heterogeneity was significant, QT = 23.49, p = 0.03, I2 = 45%, which suggested a moderate variance among the included studies. The year of publication (χ2(1) = 4.08, p = 0.04) and the questionnaire used to assess symptoms (χ2(4) = 12.65, p = 0.01) significantly moderated the effect of the interventions and reduced heterogeneity. Overall, results showed that HRVB improves depressive symptoms in several psychophysiological conditions in adult samples and should be considered as a valid technique to increase psychological well-being.

Effects of Buddhist walking meditation on exercise capacity and quality of life of patients with chronic heart failure: A randomized controlled trial

BACKGROUND

Buddhist walking meditation (BWM) is widely practiced in many countries. However, there is a lack of evidence relating to its effectiveness for patients with heart failure (HF).

PURPOSE

To determine the effects of a six-week BWM program on exercise capacity, quality of life, and hemodynamic response in patients with chronic HF.

METHODS

Patients with HF were randomly assigned to a BWM program or an aerobic exercise program. Each group trained at least three times a week during the six-week study period. The outcome measures included exercise capacity (six-minute walk test), disease-specific quality of life (Minnesota Living with Heart Failure Questionnaire), and hemodynamic response (blood pressure and heart rate) immediately after the six weeks of training.

RESULTS

The study enrolled 48 patients with a mean age of 65 years and a New York Heart Association functional class of II and III. At baseline, there were no significant differences in their clinical and demographic characteristics or the outcome measures. Although six patients withdrew, all participants were included in the intention-to-treat analysis. There was no statistically significant increase in the functional capacity of the BWM group; however, there was a significant improvement for the aerobic group. With both groups, there was no significant improvement in quality of life or most hemodynamic responses.

CONCLUSIONS

The six-week BWM program did not improve the functional capacity, quality of life, or hemodynamic characteristics of the HF patients, compared with the values of the patients in the aerobic exercise program.

Women's participation in stress management interventions for chronic heart failure: a meta-analysis of randomized controlled trials

Stress management interventions (SMIs) can alleviate the psychosocial stress often experienced by women with heart failure. The purpose of this meta-analysis was to summarize women's participation rates, and predictors of participation, in SMIs for the management of psychosocial distress in women with chronic HF. Studies were retrieved from bibliographic databases, reference sections of relevant papers, and research registries. Included studies (a) evaluated a SMI approach for the management of chronic HF, (b) sampled chronic HF patients, and (c) used a randomized controlled trial (RCT) design. Independent coders extracted the relevant data. Thirty-five RCTs met inclusion criteria (N = 3,649; mean age = 63.5 ± 7.0 years). All studies sampled both men and women; the mean proportion of women who participated in the trials was 38.8% (95% confidence interval [CI] = 34.5-43.4; I² = 82.4, 95% CI = 81.0-83.6). Women's participation rates were higher in studies sampling more HF patients with hypertension (B = 1.01, SE = 0.45, P = .046) but fewer HF patients prescribed beta blockers (B = -1.10, SE = 0.33, P = .006), F (2,12) = 6.27, P = 0.014, adjusted R² = 61%. SMIs may offer women a complementary or integrative approach to standard treatment to help manage the psychological distress associated with HF. Future research should explore the potential benefits of offering stress management approaches to women as part of comprehensive HF care.

A Single Session of Heart Rate Variability Biofeedback Produced Greater Increases in Heart Rate Variability Than Autogenic Training

Heart rate variability biofeedback (HRV-BF) has been confirmed to increase heart rate variability (HRV) and cardiac outflows by baroreflex in healthy populations and clinical patients. Autogenic training (AT) is common used in the psychological intervention. This study integrates a single-session of HRV-BF and AT into a high-technology mobile application (app), and examines the effects on HRV indices, breathing rates, and subjective relaxation scores. Healthy college students were recruited and assigned to the single-session HRV-BF group or AT group. Participants in the HRV-BF group received HRV-BF combined with paced breathing training, which gradually stepped down their breathing rates from 12, to 8, to 6 breaths/per min; and received feedback of HRV indices from the app. Participants in the AT group received autogenic training and feedback of heart rate from the app. A chest belt Zephyr BioHarness was connected through Bluetooth to a Zenfone5 mobile phone, it collected the signals of interbeat intervals and breathing rates at pre-training, mid-training, and post-training stages. The Kubios HRV software was used to analyze HRV indices. The results reveal higher HRV indices and lower breathing rates during mid-training and post-training in the HRV-BF group compared to the AT group. There were higher high-frequency of HRV at post-training than pre-training in the AT group. Participants of both groups increased their subjective relaxation scores after training. The HRV-BF protocol increased cardiac outflows by baroreflex and decreased breathing rates, and the AT protocol increased high-frequency of HRV. These high-technology wearable devices combined with psychological interventions will apply to various populations in the future.

One-Year Cardiovascular Prognosis of the Randomized, Controlled, Short-Term Heart Rate Variability Biofeedback Among Patients with Coronary Artery Disease

PURPOSE

Heart rate variability biofeedback (HRV-BF) is an effective psychophysiological intervention, with short-term effects of increased autonomic nervous system homeostasis, strengthened baroreflex sensitivity, and decreased hostility in patients with coronary artery disease (CAD). The study examined the 1-year HRV-BF effect on cardiovascular prognosis of these patients.

METHODS

Of 222 patients with CAD referred by cardiologists, 210 were screened and randomly assigned to the HRV-BF and control groups. All patients received psychophysiological assessment and completed psychological questionnaires at pre- and post-interventions and 1-year follow-up. The cardiovascular prognosis primary endpoints included hospital readmission, emergency revisits, and mortality.

RESULTS

The HRV-BF group had fewer all-cause readmissions (12.00 vs. 25.42%) and all-cause emergency visits (13.33 vs. 35.59%) than the control group. The low-frequency HRV in the HRV-BF group increased at post-intervention and 1-year follow-up compared with that at pre-intervention. Although no significant interaction effect was found in the standard deviation of the normal-to-normal intervals (F = 2.96, p = 0.055), it increased by 26.68% from pre- to post-intervention and 15.77% from pre-intervention to follow-up in the HRV-BF group. However, it decreased by 3.60% from pre- to post-intervention and increased by 1.99% from pre-intervention to follow-up in the control group. Depression and hostility scores decreased significantly at post-intervention and 1-year follow-up only in the HRV-BF group.

CONCLUSIONS

The long-term HRV-BF effect was confirmed by improved cardiovascular prognosis, increased cardiac autonomic homeostasis and baroreflex sensitivity, and decreased depression and hostility. HRV-BF is an effective psychophysiological intervention with short- and long-term effects in cardiac rehabilitation programs.

Mind-Body Interventions for Individuals With Heart Failure: A Systematic Review of Randomized Trials

BACKGROUND

The effects of mind-body interventions (MBIs) (eg, Tai Chi, yoga, meditation) for individuals with heart failure (HF) have not been systematically evaluated.

METHODS AND RESULTS

We performed a systematic review of randomized controlled trials (RCTs) examining the effects of MBIs in HF. We extracted participant characteristics, MBI procedure, outcomes assessed, and main results of English-language RCTs before October 2016. We identified 24 RCTs (n = 1314 participants) of 9 MBI types: Tai Chi (n = 7), yoga (n = 4), relaxation (n = 4), meditation (n = 2), acupuncture (n = 2), biofeedback (n = 2), stress management (n = 1), Pilates (n = 1), and reflexology (n = 1). Most (n = 22, 95.8%) reported small-to-moderate improvements in quality of life (14/14 studies), exercise capacity (8/9 studies), depression (5/5 studies), anxiety and fatigue (4/4 studies), blood pressure (3/5 studies), heart rate (5/6 studies), heart rate variability (7/9 studies), and B-type natriuretic peptide (3/4 studies). Studies ranged from 4 minutes to 26 weeks and group sizes ranged from 8 to 65 patients per study arm.

CONCLUSIONS

Although wide variability exists in the types and delivery, RCTs of MBIs have demonstrated small-to-moderate positive effects on HF patients' objective and subjective outcomes. Future research should examine the mechanisms by which different MBIs exert their effects.

The Application of Heart Rate Variability Biofeedback to Medical and Mental Health Disorders

Heart rate variability (HRV) is a medical index for morbidity and wellness. Lower HRV accompanies many illnesses; high HRV accompanies healthy states, resilience, and optimal functioning. Heart rate variability biofeedback (HRVB) uses real-time electronic feedback of the moment-to-moment changes in HRV to train patients to produce increases in HRV. Outcome studies on HRVB have shown therapeutic benefit for a wide variety of medical and mental health disorders. Lehrer and colleagues have published evidence-based protocols for HRV assessment and HRV treatment. Here, the authors review outcome studies on a sampling of common disorders: asthma, chronic muscle pain, depression, heart failure, hypertension, and posttraumatic stress disorder. HRVB offers promising therapeutic benefit for any medical or mental health disorder known to be accompanied by autonomic nervous system dysregulation.

A Systematic Review of Relaxation, Meditation, and Guided Imagery Strategies for Symptom Management in Heart Failure

BACKGROUND

Pain, dyspnea, fatigue, and sleep disturbance are prevalent and distressing symptoms in persons with advanced heart failure. Although many lifestyle and self-care interventions have been developed to control heart failure progression, very few studies have explored treatments exclusively for symptom palliation. Cognitive-behavioral strategies may be effective treatment for these symptoms in advanced heart failure.

OBJECTIVE

A systemic review was conducted to describe the effect of cognitive-behavioral strategies on pain, dyspnea, fatigue, and sleep disturbance in patients with heart failure.

METHODS

CINAHL, Medline, and PsychINFO were searched from inception through December 2014. Articles were selected for inclusion if they tested a cognitive-behavioral strategy using a quasi-experimental or experimental design, involved a sample of adults with heart failure, and measured pain, dyspnea, fatigue, sleep disturbance, or symptom-related quality of life. The 2 authors evaluated study quality, abstracted data elements from each study, and synthesized findings.

RESULTS

Thirteen articles describing 9 unique studies met criteria and were included in the review. Five studies tested relaxation strategies, 3 tested meditation strategies, and 1 tested a guided imagery strategy. Of the 9 studies, 7 demonstrated some improvement in symptom outcomes. Relaxation, meditation, guided imagery, or combinations of these strategies resulted in less dyspnea and better sleep compared with attention control or usual care conditions and reduced pain, dyspnea, fatigue, and sleep disturbance within treatment groups (pretreatment to posttreatment). Symptom-related quality of life was improved with meditation compared with attention control and usual care conditions and improved pre- to post-guided imagery.

CONCLUSIONS

Studies exploring cognitive-behavioral symptom management strategies in heart failure vary in quality and report mixed findings but indicate potential beneficial effects of relaxation, meditation, and guided imagery on heart failure-related symptoms. Future research should test cognitive-behavioral strategies in rigorously designed efficacy trials, using samples selected for their symptom experience, and measure pain, dyspnea, fatigue, and sleep disturbance outcomes with targeted symptom measures.

Exercise training-induced modification in autonomic nervous system: An update for cardiac patients

Patients with cardiovascular disease show autonomic dysfunction, including sympathetic activation and vagal withdrawal, which leads to fatal events. This review aims to place sympathovagal balance as an essential element to be considered in management for cardiovascular disease patients who benefit from a cardiac rehabilitation program. Many studies showed that exercise training, as non-pharmacologic treatment, plays an important role in enhancing sympathovagal balance and could normalize levels of markers of sympathetic flow measured by microneurography, heart rate variability or plasma catecholamine levels. This alteration positively affects prognosis with cardiovascular disease. In general, cardiac rehabilitation programs include moderate-intensity and continuous aerobic exercise. Other forms of activities such as high-intensity interval training, breathing exercises, relaxation and transcutaneous electrical stimulation can improve sympathovagal balance and should be implemented in cardiac rehabilitation programs. Currently, the exercise training programs in cardiac rehabilitation are individualized to optimize health outcomes. The sports science concept of the heart rate variability (HRV)-vagal index used to manage exercise sessions (for a goal of performance) could be implemented in cardiac rehabilitation to improve cardiovascular fitness and autonomic nervous system function.

Heart Rate Variability and the Efficacy of Biofeedback in Heroin Users with Depressive Symptoms

Objective

Low heart rate variability (HRV) has been confirmed in heroin users, but the effects of heart-rate-variability–biofeedback in heroin users remain unknown. This study examined (1) correlations between depression and HRV indices; (2) group differences in HRV indices among a heroin-user group, a group with major depressive disorder but no heroin use, and healthy controls; and (3) the effects of heart-rate-variability–biofeedback on depressive symptoms, HRV indices, and respiratory rates within the heroin group.

Methods

All participants completed a depression questionnaire and underwent electrocardiogram measurements, and group differences in baseline HRV indices were examined. The heroin group underwent electrocardiogram and respiration rate measurements at baseline, during a depressive condition, and during a happiness condition, before and after which they took part in the heart-rate-variability–biofeedback program. The effects of heart-rate-variability–biofeedback on depressive symptoms, HRV indices, and respiration rates were examined.

Results

There was a negative correlation between depression and high frequency of HRV, and a positive correlation between depression and low frequency to high frequency ratio of HRV. The heroin group had a lower overall and high frequency of HRV, and a higher low frequency/high frequency ratio than healthy controls. The heart-rate-variability–biofeedback intervention increased HRV indices and decreased respiratory rates from pre-intervention to post-intervention.

Conclusion

Reduced parasympathetic and increased sympathetic activations were found in heroin users. Heart-rate-variability–biofeedback was an effective non-pharmacological intervention to restore autonomic balance.

Heart rate variability biofeedback intervention for reduction of psychological stress during the early postpartum period

This study examined the effectiveness of heart rate variability (HRV) biofeedback intervention for reduction of psychological stress in women in the early postpartum period. On postpartum day 4, 55 healthy subjects received a brief explanation about HRV biofeedback using a portable device. Among them, 25 mothers who agreed to implement HRV biofeedback at home were grouped as the biofeedback group, and other 30 mothers were grouped as the control group. At 1 month postpartum, there was a significant decrease in total Edinburgh Postnatal Depression Scale score (P < 0.001) in the biofeedback group; this change was brought about mainly by decreases in items related to anxiety or difficulty sleeping. There was also a significant increase in standard deviation of the normal heartbeat interval (P < 0.01) of the resting HRV measures in the biofeedback group after adjusting for potential covariates. In conclusion, postpartum women who implemented HRV biofeedback after delivery were relatively free from anxiety and complained less of difficulties sleeping at 1 month postpartum. Although the positive effects of HRV biofeedback may be partly attributable to intervention effects, due to its clinical outcome, HRV biofeedback appears to be recommendable for many postpartum women as a feasible health-promoting measure after childbirth.

Randomized controlled trial of heart rate variability biofeedback in cardiac autonomic and hostility among patients with coronary artery disease

Hostility is a psychosocial risk factor that may decrease heart rate variability (HRV) in coronary artery disease (CAD) through cardiac autonomic imbalance. Heart rate variability biofeedback (HRV-BF) increases HRV indices and baroreflex gain. This study examines the effectiveness of HRV-BF in restoring cardiac autonomic balance and decreasing hostility among patients with CAD. One hundred and fifty-four patients with CAD were assigned randomly to receive 6 weeks of HRV-BF, in addition to the standard medical care received by the wait-list control (WLC) group. A 5-min electrocardiogram, blood pressure, and hostility were assessed pre-intervention, post-intervention, and at 1-month follow-up. The standard deviation of normal-to-normal intervals (SDNN), low frequency (LF), and log LF at post-intervention was significantly higher than that at pre-intervention in the HRV-BF group. Baseline log LF was significantly higher post-intervention and at follow-up after HRV-BF training than at pre-intervention. The treatment curve of log LF pre-session increased significantly after session 2, which was maintained to post-intervention. Expressive hostility, suppressive hostility, and hostility total score at post-intervention and one-month follow-up after HRV-BF were significantly lower than at pre-intervention. This study showed increased HRV and decreased expressive and suppressive hostility behavior in patients with CAD following HRV-BF.

Exercise-based cardiac rehabilitation in patients with chronic heart failure: a Dutch practice guideline

Rationale

To improve the quality of exercise-based cardiac rehabilitation (CR) in patients with chronic heart failure (CHF) a practice guideline from the Dutch Royal Society for Physiotherapy (KNGF) has been developed.

Guideline development

A systematic literature search was performed to formulate conclusions on the efficacy of exercise-based intervention during all CR phases in patients with CHF. Evidence was graded (1–4) according the Dutch evidence-based guideline development criteria.

Clinical and research recommendations

Recommendations for exercise-based CR were formulated covering the following topics: mobilisation and treatment of pulmonary symptoms (if necessary) during the clinical phase, aerobic exercise, strength training (inspiratory muscle training and peripheral muscle training) and relaxation therapy during the outpatient CR phase, and adoption and monitoring training after outpatient CR.

Applicability and implementation issues

This guideline provides the physiotherapist with an evidence-based instrument to assist in clinical decision-making regarding patients with CHF. The implementation of the guideline in clinical practice needs further evaluation.

Conclusion

This guideline outlines best practice standards for physiotherapists concerning exercise-based CR in CHF patients. Research is needed on strategies to improve monitoring and follow-up of the maintenance of a physical active lifestyle after supervised CR.

Interventions for Grandmothers: Comparative Effectiveness of Resourcefulness Training, HRV Biofeedback, and Journaling

In the United States, more than one million grandmothers are raising their grandchildren, and this can be stressful, produce depressive symptoms, and adversely affect their quality of life. The pilot trial of 60 grandmothers reported here examined the effects of a cognitive behavioral intervention (resourcefulness training), biofeedback control training (focused on heart rate variability), and journaling on measures of perceived stress, depressive symptoms, and quality of life. Comparative analysis revealed a decrease in stress with all three conditions; a decrease in depressive symptoms in the resourcefulness training group; and improved quality of life in the resourcefulness training and biofeedback groups.

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

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.

A brief review and clinical application of heart rate variability biofeedback in sports, exercise, and rehabilitation medicine

CONTEXT

An important component of the effective management of chronic noncommunicable disease is the assessment and management of psychosocial stress. The measurement and modulation of heart rate variability (HRV) may be valuable in this regard.

OBJECTIVE

To describe the measurement and physiological control of HRV; to describe the impact of psychosocial stress on cardiovascular disease, metabolic syndrome, and chronic respiratory disease, and the relationship between these diseases and changes in HRV; and to describe the influence of biofeedback and exercise on HRV and the use of HRV biofeedback in the management of chronic disease.

DATA SOURCES AND STUDY SELECTION

The PubMed, Medline, and Embase databases were searched (up to August 2013). Additional articles were obtained from the reference lists of relevant articles and reviews. Articles were individually selected for further review based on the quality and focus of the study, and the population studied.

RESULTS

Heart rate variability is reduced in stress and in many chronic diseases, and may even predict the development and prognosis of some diseases. Heart rate variability can be increased with both exercise and biofeedback. Although the research on the effect of exercise is conflicting, there is evidence that aerobic training may increase HRV and cardiac vagal tone both in healthy individuals and in patients with disease. Heart rate variability biofeedback is also an effective method of increasing HRV and cardiac vagal tone, and has been shown to decrease stress and reduce the morbidity and mortality of disease.

CONCLUSION

The assessment and management of psychosocial stress is a challenging but important component of effective comprehensive lifestyle interventions for the management of noncommunicable disease. It is, therefore, important for the sports and exercise physician to have an understanding of the therapeutic use of HRV modulation, both in the reduction of stress and in the management of chronic disease.

Coherence: a novel nonpharmacological modality for lowering blood pressure in hypertensive patients

This study examined the efficacy of teaching emotional self-regulation techniques supported by heart rhythm coherence training (emWave Personal Stress Reliever) as a means to quickly lower blood pressure (BP) in patients diagnosed with hypertension. Previous studies have demonstrated systemic reductions in BP in both high stress populations and patients diagnosed with hypertension using this approach, but to the best of our knowledge, an investigation of their ability to produce immediate reductions in BP had not been published in the medical literature. The study was a randomized controlled design with 62 hypertensive participants who were divided into three groups. Group 1 was taking hypertensive medication, was taught self-regulation technique, and used heart rate variability coherence (HRVC) training devices. Group 2 was not yet taking medication and was trained in the same intervention. Group 3 was taking hypertensive medication but did not receive the intervention and was instructed to relax between the BP assessments. An analysis of covariates was conducted to compare the effectiveness of three different interventions on reducing the participants' BP. The use of the self-regulation technique and the HRVC-monitoring device was associated with a significantly greater reduction in mean arterial pressure in the two groups who used the intervention as compared with the relaxation-plus-medication group. Additionally, the group not taking medication that used the intervention also had a significantly greater reduction in systolic BP than the relaxation- plus-medication group. These results suggest that self-regulation techniques that incorporate the intentional generation of positive emotions to facilitate a shift into the psychophysiological coherence state are an effective approach to lowering BP. This approach to reducing BP should be considered a simple and effective approach that can easily be taught to patients to quickly lower their BP in stressful situations. The technique should be especially useful when hypertensive patients are experiencing stressful emotions or reactions to stressors. It is possible that the BP reductions associated with the use of the technique leads to a change in the physiological set-point for homeostatic regulation of BP. Further studies should examine if large scale implementations of such heart-based coherence techniques could have a significant impact on reducing risk of mortality and morbidity in hypertensive patients.

The Promise of Heart Rate Variability Biofeedback: Evidence-Based Applications

Heart rate variability biofeedback has enjoyed increased popularity in recent years. In this review, empirical evidence from multiple sources is presented from the point of view of possible mechanisms of effect. While more research is clearly needed, the data thus far are certainly promising.

Psychophysiologic Remodeling of the Failing Human Heart

Autonomic imbalance is a therapeutic target in heart failure patients. Overactivation of the sympathetic branch of the autonomic nervous system has for years been treated with beta-adrenergic blocking drugs, although it cannot be long before invasive therapies such as renal sympathetic denervation, currently being tested for resistant hypertension, make their way to the heart failure arena. Insufficient parasympathetic input to the heart is already being augmented with implanted vagal nerve stimulators. It is our contention that biofeedback training could provide much of the same benefit as these more invasive therapies in improving autonomic imbalance, with the added advantage of increasing patient self-efficacy. This article describes a pilot study of biofeedback training in patients with end-stage heart failure awaiting heart transplantation. It was our goal to show not only that patients would appreciate this training and benefit from it but also that patient-controlled autonomic modulation could actually reverse the cellular and molecular markers of heart failure, or remodel the failing heart, similar to what we had previously shown for other types of heart failure therapy such as the left ventricular assist device. To our knowledge, this is the first study to demonstrate changes in the biology of the failing heart in response to a psychophysiologic intervention.

How Does Heart Rate Variability Biofeedback Work? Resonance, the Baroreflex, and Other Mechanisms

Heart rate variability biofeedback is known to have multiple effects on the cardiovascular system, the respiratory system, and emotional reactivity. This paper reviews the origins of work on heart rate variability biofeedback, and mechanisms for its various effects, including direct effects on the baroreflex system and gas exchange efficiency, as well as indirect effects on emotional reactivity and possibly inflammatory activity. Resonance in the cardiovascular system is explained, as well as ways that heart rate variability biofeedback stimulates these resonance effects, through interactions between respiratory sinus arrhythmia and the baroreflex system. Relationships of these mechanisms to various clinical applications of heart rate variability biofeedback are explored, as are future extensions of biofeedback to the vascular tone baroreflex.

Resilience Training Program Reduces Physiological and Psychological Stress in Police Officers

Research suggests that police work is among the most stressful occupations in the world and officers typically suffer a variety of physiological, psychological, and behavioral effects and symptoms. Officers operating under severe or chronic stress are likely to be at greater risk of error, accidents, and overreactions that can compromise their performance, jeopardize public safety, and pose significant liability costs to the organization. Therefore, this study explored the nature and degree of physiological activation typically experienced of officers on the job and the impact of the Coherence Advantage resilience and performance enhancement training on a group of police officers from Santa Clara County, California. Areas assessed included vitality, emotional well-being, stress coping and interpersonal skills, work performance, workplace effectiveness and climate, family relationships, and physiological recalibration following acute stressors. Physiological measurements were obtained to determine the real-time cardiovascular impact of acutely stressful situations encountered in highly realistic simulated police calls used in police training and to identify officers at increased risk of future health challenges. The resilience-building training improved officers' capacity to recognize and self-regulate their responses to stressors in both work and personal contexts. Officers experienced reductions in stress, negative emotions, depression, and increased peacefulness and vitality as compared to a control group. Improvements in family relationships, more effective communication and cooperation within work teams, and enhanced work performance also were noted. Heart rate and blood pressure measurements taken during simulated police call scenarios showed that acutely stressful circumstances typically encountered on the job result in a tremendous degree of physiological activation, from which it takes a considerable amount of time to recover. Autonomic nervous system assessment based on heart rate variability (HRV) analysis of 24-hour electrocardiogram (ECG) recordings revealed that 11% of the officers were at higher risk for sudden cardiac death and other serious health challenges. This is more than twice the percentage typically found in the general population and is consistent with epidemiological data indicating that police officers have more than twice the average incidence of cardiovascular-related disease. The data suggest that training in resilience building and self-regulation skills could significantly benefit police organizations by improving judgment and decision making and decreasing the frequency of onthe-job driving accidents and the use of excessive force in high-stress situations. Potential outcomes include fewer citizens' complaints, fewer lawsuits, decreased organizational liabilities, and increased community safety. Finally, this study highlights the value of 24-hour HRV analysis as a useful screening tool to identify officers who are at increased risk, so that efforts can be made to reverse or prevent the onset of disease in these individuals.

Matter over mind: a randomised-controlled trial of single-session biofeedback training on performance anxiety and heart rate variability in musicians

BACKGROUND

Musical performance is a skilled activity performed under intense pressure, thus is often a profound source of anxiety. In other contexts, anxiety and its concomitant symptoms of sympathetic nervous system arousal have been successfully ameliorated with HRV biofeedback (HRV BF), a technique involving slow breathing which augments autonomic and emotional regulatory capacity.

OBJECTIVE

This randomised-controlled study explored the impact of a single 30-minute session of HRV BF on anxiety in response to a highly stressful music performance.

METHODS

A total of 46 trained musicians participated in this study and were randomly allocated to a slow breathing with or without biofeedback or no-treatment control group. A 3 Group×2 Time mixed experimental design was employed to compare the effect of group before and after intervention on performance anxiety (STAI-S) and frequency domain measures of HRV.

RESULTS

Slow breathing groups (n=30) showed significantly greater improvements in high frequency (HF) and LF/HF ratio measures of HRV relative to control (n=15) during 5 minute recordings of performance anticipation following the intervention (effect size: η(2) =0.122 and η(2) =0.116, respectively). The addition of biofeedback to a slow breathing protocol did not produce differential results. While intervention groups did not exhibit an overall reduction in self-reported anxiety, participants with high baseline anxiety who received the intervention (n=15) displayed greater reductions in self-reported state anxiety relative to those in the control condition (n=7) (r=0.379).

CONCLUSIONS

These findings indicate that a single session of slow breathing, regardless of biofeedback, is sufficient for controlling physiological arousal in anticipation of psychosocial stress associated with music performance and that slow breathing is particularly helpful for musicians with high levels of anxiety. Future research is needed to further examine the effects of HRV BF as a low-cost, non-pharmacological treatment for music performance anxiety.

Heart rate variability biofeedback decreases blood pressure in prehypertensive subjects by improving autonomic function and baroreflex

BACKGROUND

Individuals with prehypertension are at risk of hypertension and cardiovascular diseases, and yet efficient interventions are lagging behind. Studies indicate that heart rate variability-biofeedback (HRV-BF) increases HRV and baroreflex sensitivity (BRS) as well as reduces related pathological symptoms, suggesting potentially beneficial effects of HRV-BF on prehypertension, but little is known about these effects. In this study, these effects were investigated and their mechanisms were explored.

OBJECTIVES

The effect of HRV-BF on prehypertension in young adults and its potential mechanism were explored.

DESIGN

Forty-three (43) individuals with prehypertension were recruited and classified into three categories: HRV-BF group, slow abdominal breathing group, and control group. All groups were assessed with measurements of noninvasive blood pressure (BP), BRS, respiration, and galvanic skin response (GSR) at pre-intervention, in the entire process of each session, at postintervention, as well as at a 3-month follow-up.

INTERVENTIONS

Subjects participated in a 10-session HRV-BF protocol or simple slow abdominal breathing protocol conducted over 5 weeks. A 3-month follow-up was also performed on these individuals.

RESULTS

The incidence of prehypertension was as high as 14.5% in young college students. Individuals with prehypertension were lower in BRS (7.5±5.2 ms/mm Hg) and HRV (log10-transformed of the standard deviation of normal-to-normal beats [SDNN]=1.62±0.13 ms, lgTotal power of spectral density in the range of frequencies between 0 and 0.4Hz (TP)=8.02±0.55 ms2) than those with normal blood pressure (BRS=18.4±7.4 ms/mm Hg, lgSDNN=1.79±0.10 ms, lgTP=8.68±0.85 ms2). HRV-BF reduced blood pressure (from 131.7±8.7/79.3±4.7 mm Hg to 118.9±7.3 mm Hg/71.9±4.9 mm Hg, p<0.01), increased BRS (from 7.0±5.9 ms/mm Hg to 15.8±5.3 ms/mm Hg, p<0.01) and increased HRV (lgSDNN from 1.61±0.11 to 1.75±0.05 ms, and lgTP from 8.07±0.54 to 9.08±0.41 ms2, p<0.01). These effects were more obvious than those of the slow-breathing group, and remained for at least 3 months. HRV-BF also significantly increased vagus-associated HRV indices and decreased GSR (indices of sympathetic tone).

CONCLUSIONS

These effects suggest that HRV-BF, a novel behavioral neurocardiac intervention, could enhance BRS, improve the cardiac autonomic tone, and facilitate BP adjustment for individuals with prehypertension.

Social science, behavioural medicine, and the tomato effect

'Behavioural medicine' is poised to contribute to the quality of health to the benefit of patients and physicians. There is a need for medical students and residents to better understand the field of behavioural medicine, and for practising physicians to incorporate it in medical education and clinical practice. This paper seeks to correct an erroneous conceptualization of behavioural medicine as being limited to psychosocial and mental health adjustments, and to provide examples of selected applications for medical conditions, including those that are not primarily regarded as requiring changes in lifestyle or psychotherapy. In fact, there are dramatic treatment and intervention protocols available that employ behavioural procedures that can provide relief for patients in all medical and dental specialties and that deserve to be considered along with conventional treatment protocols.

Effects of heart rate variability biofeedback in subjects with stress-related chronic neck pain: a pilot study

Recent studies focusing on autonomic nervous system (ANS) dysfunctions, together with theoretical pathophysiological models of musculoskeletal disorders, indicate the involvement of ANS regulation in development and maintenance of chronic muscle pain. Research has demonstrated the effectiveness of heart rate variability (HRV) biofeedback (BF) in increasing HRV and reducing the symptoms of different disorders characterized by ANS aberration. The study investigated the effects of resonance frequency HRV BF on autonomic regulation and perceived health, pain, stress and disability in 24 subjects with stress-related chronic neck-shoulder pain. Twelve subjects participated in 10 weekly sessions of resonant HRV BF and were compared to a control group. Subjective reports and HRV measures during relaxation and in response to a standardized stress protocol were assessed for both groups pre- and post-intervention. Group × time interactions revealed a significantly stronger increase over time in perceived health (SF-36) for the treatment group, including vitality, bodily pain and social functioning. Interactions were also seen for HRV during relaxation and reactivity to stress. The present pilot study indicates improvement in perceived health over a 10 week intervention with HRV-biofeedback in subjects with chronic neck-pain. Increased resting HRV as well as enhanced reactivity to hand grip and cold pressor tests might reflect beneficial effects on ANS regulation, and suggest that this intervention protocol is suitable for a larger controlled trial.

Biofeedback of heart rate variability and related physiology: a critical review

Low heart rate variability (HRV) characterizes several medical and psychological diseases. HRV biofeedback is a newly developed approach that may have some use for treating the array of disorders in which HRV is relatively low. This review critically appraises evidence for the effectiveness of HRV and related biofeedback across 14 studies in improving (1) HRV and baroreflex outcomes and (2) clinical outcomes. Results revealed that HRV biofeedback consistently effectuates acute improvements during biofeedback practice, whereas the presence of short-term and long-term carry-over effects is less clear. Some evidence suggests HRV biofeedback may result in long-term carry-over effects on baroreflex gain, which is an area most promising for future investigations. On the other hand, concerning clinical outcomes, there is ample evidence attesting to efficacy of HRV biofeedback. However, because clinical and physiological outcomes do not improve concurrently in all cases, the mechanism by which HRV biofeedback results in salutary effects in unclear. Considerations for the field in addressing shortcomings of the reviewed studies and advancing understanding of the way in which HRV biofeedback may improve physiological and clinical outcomes are offered in light of the reviewed evidence.