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

Effect of Heart Rate Variability Biofeedback on Cardiac Autonomic Activation and Diabetes Self-Care in Patients with Type II Diabetes Mellitus

In type 2 diabetes mellitus (T2DM), decreased autonomic activation and heightened negative emotions may worsen glycemic control. This study investigated the effects of heart rate variability biofeedback (HRVB) on autonomic activation, negative emotions, diabetes self-care, and glycemic control in patients with T2DM. A total of 61 participants with T2DM were assigned to either the HRVB group (n = 30; 62.67 ± 7.28 years; 14 females) or the control group (n = 31; 63.39 ± 6.96 years; 14 females). Both groups received the treatment as usual, and the HRVB group received 60 min of HRVB sessions weekly for 6 weeks. Participants completed psychological questionnaires, a resting electrocardiogram (ECG), and breathing rate assessments at pre- and post-tests. Heart rate variability (HRV) indices were derived from ECG data, and glycated hemoglobin (HbA1c) levels were collected from the electronic medical records. The analysis revealed significant Group × Time interaction effects on HRV indices, breathing rate, depression symptoms, and diabetes self-care behavior. The HRVB group demonstrated higher HRV indices, lower breathing rate, and improved diabetes self-care behavior compared to the control group. Moreover, the HRVB group showed enhanced HRV indices and diabetes self-care behavior, as well as reduced breathing rate and depression in the post-test compared to the pre-test. However, there was no significant interaction effect on HbA1c levels. Six sessions of HRVB proved effective as a complementary therapy for T2DM, enhancing HRV indices, alleviating depressive symptoms, and promoting better diabetes self-care behaviors.

Effects of Heart Rate Variability (HRV) Biofeedback in Pulmonary Indicators and HRV Indices Among Patients with Chronic Obstructive Pulmonary Disease

Patients with chronic obstructive pulmonary disease (COPD) exhibit reduced cardiac autonomic activity, linked to poor prognosis and exercise intolerance. While heart rate variability biofeedback (HRVB) can enhance cardiac autonomic activity in various diseases, its use in patients with COPD is limited. This study explored the impact of the HRVB on cardiac autonomic activity and pulmonary indicators in patients with COPD. Fifty-three patients with COPD were assigned to either the HRVB (n = 26) or the control group (n = 27), with both groups receiving standard medical care. The HRVB group also underwent one-hour HRVB sessions weekly for six weeks. All participants had pre- and post-test measurements, including the Six-Minute Walking Test (6MWT), lead II electrocardiogram (ECG) recording, Modified Medical Research Council Dyspnea Scale (mMRC), body mass index, airflow obstruction, dyspnea, and exercise capacity (BODE) index. ECG data were analyzed for heart rate variability (HRV) as an index of cardiac autonomic activity. A two-way mixed analysis of variances demonstrated significant interaction effects of Group × Time in pulmonary indicators and HRV indices. The HRVB group exhibited significant post-test improvements, with decreased mMRC and BODE scores and increased 6MWT distance and HRV indices, compared to pre-test results. The 6MWT distance significantly increased and mMRC significantly decreased at post-test in the HRVB group compared with the control group. This study confirmed the efficacy of HRVB as an adjunct therapy in patients with COPD, showing improvements in exercise capacity, breathing difficulties, and cardiac autonomic activity.

The Effect of Stress-Reducing Interventions on Heart Rate Variability in Cardiovascular Disease: A Systematic Review and Meta-Analysis

Stress is recognized as a significant trigger and exacerbator of various medical conditions, particularly in the field of cardiovascular disease (CVD). Given that heart rate variability (HRV) offers insight into the functioning of the autonomic nervous system and has been identified as a predictive factor for increased cardiovascular mortality, exploring the correlation between stress and HRV is pertinent. We systematically reviewed trials where researchers investigated the effects of stress-reducing interventions on biomarkers and time-domain/frequency-domain parameters of HRV in CVD. Eligible studies underwent meta-analysis utilizing a random-effects model. The meta-analysis showed overall beneficial effects of stress-reducing interventions on HRV for the standard deviation of Normal-to-Normal intervals (SDNN) in short-term and 24 h assessments, as well as for the low-frequency power (LF) in short-term assessment. Overall effect sizes were notably high and showed significant p-values (short-term SDNN: MD = 6.43, p = 0.01; 24 h SDNN: MD = 10.92, p = 0.004; short-term LF: MD = 160.11, p < 0.001). Our findings highlight the significant impact of stress-reducing interventions in modulating HRV by influencing short-term SDNN and LF parameters, as well as the 24 h assessment of SDNN. These results emphasize the importance of stress-reducing measures in lowering the risk of further progression in CVD and improving patient outcomes.

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.

Heart Rate Variability Measurement through a Smart Wearable Device: Another Breakthrough for Personal Health Monitoring?

Heart rate variability (HRV) is a measurement of the fluctuation of time between each heartbeat and reflects the function of the autonomic nervous system. HRV is an important indicator for both physical and mental status and for broad-scope diseases. In this review, we discuss how wearable devices can be used to monitor HRV, and we compare the HRV monitoring function among different devices. In addition, we have reviewed the recent progress in HRV tracking with wearable devices and its value in health monitoring and disease diagnosis. Although many challenges remain, we believe HRV tracking with wearable devices is a promising tool that can be used to improve personal health.

Four Sessions of Combining Wearable Devices and Heart Rate Variability (HRV) Biofeedback are Needed to Increase HRV Indices and Decrease Breathing Rates

Heart rate variability biofeedback (HRVB) is a behavioral intervention that uses resonance frequency breathing to synchronize the heart rate and breathing patterns. This study aimed to explore how many sessions of wearable HRVB devices are needed to increase the HRV index and decrease breathing rates and to compare the HRVB protocol with other psychological intervention programs in HRV indices and breathing rates. Sixty-four participants were randomly assigned to either the HRVB or relaxation training (RT) group. Both groups received interbeat intervals (IBIs) and breathing rates measurement at the pre-training baseline, during training, and post-training baseline from weeks 1 to 4. IBIs were transformed into HRV indices as the index of the autonomic nervous system. The Group × Week interaction effects significantly in HRV indices and breathing rates. The between-group comparison found a significant increase in HRV indices and decreased breathing rates in the HRVB group than in the RT group at week 4. The within-session comparison in the HRVB group revealed significantly increased HRV indices and decreased breathing rates at weeks 3 and 4 than at weeks 1 and 2. There was a significant increase in HRV indices and a decrease in breathing rates at mid- and post-training than pre-training in the HRVB group. Therefore, 4 weeks of HRVB combined with a wearable device are needed in increasing HRV indices and decrease breathing rates compared to the relaxation training. Three weeks of HRVB training are the minimum requirement for increasing HRV indices and reducing breathing rates compared to the first week of HRVB.

Neuromodulation Applied to Diseases: The Case of HRV Biofeedback

The vagus or “wandering” nerve is the main branch of the parasympathetic nervous system (PNS), innervating most internal organs crucial for health. Activity of the vagus nerve can be non-invasively indexed by heart-rate variability parameters (HRV). Specific HRV parameters predict less all-cause mortality, lower risk of and better prognosis after myocardial infarctions, and better survival in cancer. A non-invasive manner for self-activating the vagus is achieved by performing a slow-paced breathing technique while receiving visual feedback of one’s HRV, called HRV-biofeedback (HRV-B). This article narratively reviews the biological mechanisms underlying the role of vagal activity and vagally mediated HRV in hypertension, diabetes, coronary heart disease (CHD), cancer, pain, and dementia. After searching the literature for HRV-B intervention studies in each condition, we report the effects of HRV-B on clinical outcomes in these health conditions, while evaluating the methodological quality of these studies. Generally, the levels of evidence for the benefits of HRV-B is high in CHD, pain, and hypertension, moderate in cancer, and poor in diabetes and dementia. Limitations and future research directions are discussed.

The Effects of Heart Rate Variability (HRV) Biofeedback on HRV Reactivity and Recovery During and After Anger Recall Task for Patients with Coronary Artery Disease

Patients with coronary artery disease (CAD) often experience anger events before cardiovascular events. Anger is a psychological risk factor and causes underlying psychophysiological mechanisms to lose balance of the autonomic nervous system (ANS). The heart rate variability (HRV) was the common index for ANS regulation. It has been confirmed that heart rate variability biofeedback (HRV-BF) restored ANS balance in patients with CAD during the resting state. However, the effects of HRV-BF during and after the anger event remain unknown. This study aimed to examine the effects of HRV-BF on ANS reactivity and recovery during the anger recall task in patients with CAD. This study was a randomized control trial with a wait-list control group design, with forty patients in the HRV-BF group (for six sessions) and 44 patients in the control group. All patients received five stages of an anger recall task, including baseline, neutral recall task, neutral recovery, anger recall task, and anger recovery. HRV reactivity in the HRV-BF group at the post-test was lower than that in the control group. HRV recovery at the post-test in the HRV-BF group was higher than that in the control group. The HRV-BF reduced ANS reactivity during anger events and increased ANS recovery after anger events for CAD patients. The possible mechanisms of HRV-BF may increase total HRV, ANS regulation, and baroreflex activation at anger events for patients with CAD, and may be a suitable program for cardiac rehabilitation.

Mobile Heart Rate Variability Biofeedback as a Complementary Intervention After Myocardial Infarction: a Randomized Controlled Study

BACKGROUND

To enhance effective prevention programs after myocardial infarction (MI), the study examined the effects and feasibility of mobile biofeedback training on heart rate variability (HRV-BF).

METHODS

Forty-six outpatients aged 41 to 79 years with a documented MI were randomized to HRV-BF versus usual care. Generalized estimating equation (GEE) analyses were performed to test improvements in measures of short- and long-time HRV, namely, the standard deviation of the normal-to-normal intervals (SDNN) and well-being after 12 weeks of HRV-BF.

RESULTS

There were intervention effects for short-time HRV (d > 0.4, p < 0.04), which were partly replicated in the GEE models that accounted for control variables: In the HRV-BF group, the high-frequency HRV (group × time interaction: β = 0.59, p = 0.04) compensated for significantly lower baseline levels than the group with usual care. In an optimal dose sample (on average two HRV-BF sessions a day), SDNN significantly increased after HRV-BF (p = 0.002) but not in the waitlist control group. Compensatory trends of HRV-BF were also found for high-frequency HRV and self-efficacy. No adverse effects of the intervention were found but neither were effects on long-time HRV measures.

CONCLUSION

The results showed the feasibility of self-guided HRV-BF for almost all post-MI patients. HRV-BF as an adjunctive behavioral treatment increased HRV, which is an indicator of lower cardiovascular risk, and self-efficacy, which suggests heightened psychological resilience. These benefits warrant confirmation and tests of sustainability in larger studies.

TRIAL REGISTRATION

The trial has not been registered due to its starting point in 2017 predating the publication of the applicable CONSORT extension for reporting social and psychological intervention trials in 2018.

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.

The Influence of Heart Rate Variability Biofeedback on Cardiac Regulation and Functional Brain Connectivity

Background

Heart rate variability (HRV) biofeedback has a beneficial impact on perceived stress and emotion regulation. However, its impact on brain function is still unclear. In this study, we aimed to investigate the effect of an 8-week HRV-biofeedback intervention on functional brain connectivity in healthy subjects.

Methods

HRV biofeedback was carried out in five sessions per week, including four at home and one in our lab. A control group played jump‘n’run games instead of the training. Functional magnetic resonance imaging was conducted before and after the intervention in both groups. To compute resting state functional connectivity (RSFC), we defined regions of interest in the ventral medial prefrontal cortex (VMPFC) and a total of 260 independent anatomical regions for network-based analysis. Changes of RSFC of the VMPFC to other brain regions were compared between groups. Temporal changes of HRV during the resting state recording were correlated to dynamic functional connectivity of the VMPFC.

Results

First, we corroborated the role of the VMPFC in cardiac autonomic regulation. We found that temporal changes of HRV were correlated to dynamic changes of prefrontal connectivity, especially to the middle cingulate cortex, the left insula, supplementary motor area, dorsal and ventral lateral prefrontal regions. The biofeedback group showed a drop in heart rate by 5.2 beats/min and an increased SDNN as a measure of HRV by 8.6 ms (18%) after the intervention. Functional connectivity of the VMPFC increased mainly to the insula, the amygdala, the middle cingulate cortex, and lateral prefrontal regions after biofeedback intervention when compared to changes in the control group. Network-based statistic showed that biofeedback had an influence on a broad functional network of brain regions.

Conclusion

Our results show that increased heart rate variability induced by HRV-biofeedback is accompanied by changes in functional brain connectivity during resting state.

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.

Novel Methodological Tools for Behavioral Interventions: The Case of HRV-Biofeedback. Sham Control and Quantitative Physiology-Based Assessment of Training Quality and Fidelity

Scientific research on heart rate variability (HRV) biofeedback is burdened by certain methodological issues, such as lack of consistent training quality and fidelity assessment or control conditions that would mimic the intervention. In the present study, a novel sham HRV-biofeedback training was proposed as a credible control condition, indistinguishable from the real training. The Yield Efficiency of Training Index (YETI), a quantitative measure based on the spectral distribution of heart rate during training, was suggested for training quality assessment. A training fidelity criterion derived from a two-step classification process based on the average YETI index and its standard deviation (YETI_SD) was suggested. We divided 57 young, healthy volunteers into two groups, each subjected to 20 sessions of either real or sham HRV-biofeedback. Five standard HRV measures (standard deviation of the NN (SDNN), root mean square of the standard deviation of the NN (RMSSD), total power, low-frequency (LF), and high-frequency (HF) power) collected at baseline, after 10 and 20 sessions were subjected to analysis of variance. Application of a training fidelity criterion improved sample homogeneity, resulting in a substantial gain in effect sizes of the group and training interactions for all considered HRV indices. Application of methodological amendments, including proper control conditions (such as sham training) and quantitative assessment of training quality and fidelity, substantially improves the analysis of training effects. Although presented on the example of HRV-biofeedback, this approach should similarly benefit other behavioral training procedures that interact with any of the many psychophysiological mechanisms in the human body.

Neurophysiological Approach by Self-Control of Your Stress-Related Autonomic Nervous System with Depression, Stress and Anxiety Patients

BACKGROUND

Heart Rate Variability Biofeedback (HRVB) is a treatment in which patients learn self-regulation of a physiological dysregulated vagal nerve function. While the therapeutic approach of HRVB is promising for a variety of disorders, it has not yet been regularly offered in a mental health treatment setting.

AIM

To provide a systematic review about the efficacy of HRV-Biofeedback in treatment of anxiety, depression, and stress related disorders.

METHOD

Systematic review in PubMed and Web of Science in 2020 with terms HRV, biofeedback, Post-Traumatic Stress Disorder (PTSD), depression, panic disorder, and anxiety disorder. Selection, critical appraisal, and description of the Random Controlled Trials (RCT) studies. Combined with recent meta-analyses.

RESULTS

The search resulted in a total of 881 studies. After critical appraisal, nine RCTs have been selected as well as two other relevant studies. The RCTs with control groups treatment as usual, muscle relaxation training and a "placebo"-biofeedback instrument revealed significant clinical efficacy and better results compared with control conditions, mostly significant. In the depression studies average reduction at the Beck Depression Inventory (BDI) scale was 64% (HRVB plus Treatment as Usual (TAU) versus 25% (control group with TAU) and 30% reduction (HRVB) at the PSQ scale versus 7% (control group with TAU). In the PTSD studies average reduction at the BDI-scale was 53% (HRV plus TAU) versus 24% (control group with TAU) and 22% (HRVB) versus 10% (TAU) with the PTSD Checklist (PCL). In other systematic reviews significant effects have been shown for HRV-Biofeedback in treatment of asthma, coronary artery disease, sleeping disorders, postpartum depression and stress and anxiety.

CONCLUSION

This systematic review shows significant improvement of the non-invasive HRVB training in stress related disorders like PTSD, depression, and panic disorder, in particular when combined with cognitive behavioral therapy or different TAU. Effects were visible after four weeks of training, but clinical practice in a longer daily self-treatment of eight weeks is more promising. More research to integrate HRVB in treatment of stress related disorders in psychiatry is warranted, as well as research focused on the neurophysiological mechanisms.

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.

The Effect of Age, Gender, and Job on Skin Conductance Response among Smartphone Users Who are Prohibited from Using Their Smartphone

The smartphone is a widely used and rapidly growing phenomenon worldwide, and problematic smartphone use is common in our society. This study's objective was to examine the gender difference of baseline and post-intervention skin conductance response (SCR) among smartphone users and explore the relationships among problematic smartphone use level, anxiety level, and SCR changes by evaluating SCR, the Zung Self-Rating Anxiety Scale score, and the Chinese version of the Smartphone Addiction Inventory (SPAI) score in a one-group baseline and post-test design. Sixty participants were recruited from two communities, and data were collected from April to June 2017. There was a significant difference in terms of SCR changes between young males and old males and between young females and old females. Additionally, the SCR changes in young females were significantly greater than those in young males with twofold mean difference. This study provides strong evidence supporting the effectiveness of SCR measurement for assessing problematic smartphone use (PSU) anxiety when users are in a withdrawal-like state. The SCR measurement can help healthcare providers identify cases with risk factors of PSU for early intervention.

Heart Rate Variability Biofeedback Increased Autonomic Activation and Improved Symptoms of Depression and Insomnia among Patients with Major Depression Disorder

Objective

Autonomic imbalance is considered a psychopathological mechanism underlying major depressive disorder (MDD). Heart rate variability (HRV) is an index for autonomic activation. Poor sleep quality is common among patients with MDD. HRV biofeedback (BF) has been used for regulating autonomic balance among patients with physical illness and mental disorders. The purpose of present study was to examine the effects of HRV-BF on depressive symptoms, sleep quality, pre-sleep arousal, and HRV indices, in patients with MDD and insomnia.

Methods

In this case-controlled study, patients with MDD and Pittsburgh Sleep Quality Index (PSQI) score higher than 6 were recruited. The HRV-BF group received weekly 60-minute protocol for 6 weeks, and the control group who have matched the age and sex received medical care only. All participants were assessed on Beck Depression Inventory-II, Back Anxiety Inventory, PSQI, and Pre-Sleep Arousal Scale. Breathing rates and electrocardiography were also performed under resting state at pre-testing, and post-testing conditions and for the HRV-BF group, also at 1-month follow-up.

Results

In the HRV-BF group, symptoms of depression and anxiety, sleep quality, and pre-sleep arousal were significantly improved, and increased HRV indices, compared with the control group. Moreover, in the HRV-BF group, significantly improved symptoms of depression and anxiety, decreased breathing rates, and increased HRV indices were detected at post-testing and at 1-month follow-up, compared with pre-testing values.

Conclusion

This study confirmed that HRV-BF is a useful psychosocial intervention for improving autonomic balance, baroreflex, and symptoms of depression and insomnia in MDD patients.

Emotion regulation after acquired brain injury: a study of heart rate variability, attentional control, and psychophysiology

Primary objective: To examine the efficacy of heart rate variability biofeedback (HRV-BF) to treat emotional dysregulation in persons with acquired brain injury. Design: A secondary analysis of a quasi-experimental study which enrolled 13 individuals with severe chronic acquired brain injury participating in a community-based programme. Response-to-treatment was measured with two HRV resonance indices (low frequency activity [LF] and low frequency/high frequency ratio [LF/HF]). Main outcome: Behavior Rating Inventory of Executive Function-informant report (emotional control subscale [EC]). Results: Results show significant correlation between LF and EC with higher LF activity associated with greater emotional control; the association between LF/HF pre-post-change score and EC is not statistically significant. A moderation model, however, demonstrates a significant influence of attention on the relation between LF/HF change and EC when attention level is high, with an increase in LF/HF activity associated with greater emotional control. Conclusions: HRV-BF is associated with large increases in HRV, and it appears to be useful for the treatment of emotional dysregulation in individuals with severe acquired brain injury. Attention training may enhance an individual's emotional control.

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.

Effects of a cardiorespiratory synchronization training mobile application on heart rate variability and electroencephalography in healthy adults

Cardiorespiratory synchronization training (CRST) uses diaphragmatic breathing to increase balance in the autonomic nervous system and reduce negative emotions. CRST integrated with high-technology mobile applications affords innovative and convenient home-based training. This study examined the effects of a CRST mobile application on heart rate variability (HRV) and electroencephalography (EEG) parameters in healthy adults. Ninety-six participants were randomly assigned to the CRST, relaxation training (RT; active control group), and control (C) groups. The CRST group received paced breathing training using a wearable device connected to a mobile application and received feedback on the HRV indices. The RT group received muscle relaxation training using a wearable device connected to a mobile application and received feedback on heart rate (HR). The training program was conducted for 1 h per week for 4 weeks. The C group did not receive any wearable device, mobile application, or psychological intervention. Psychological questionnaires on depression and anxiety and physiological measurements of the breathing rates, electrocardiography (ECG), and EEG were measured at the pretest and posttest. The CRST group showed significantly higher HRV indices and lower breathing rates at the posttest than the RT and C groups. There were no significant interaction effects on EEG parameters at pretest and posttest among the three groups. Use of a CRST mobile application increased balance in the autonomic nervous system at the resting state. This clinical evidence-based technologically advanced mobile application could be implemented in future clinical practice.

How heart rate variability affects emotion regulation brain networks

Individuals with high heart rate variability tend to have better emotional well-being than those with low heart rate variability, but the mechanisms of this association are not yet clear. In this paper, we propose the novel hypothesis that by inducing oscillatory activity in the brain, high amplitude oscillations in heart rate enhance functional connectivity in brain networks associated with emotion regulation. Recent studies using daily biofeedback sessions to increase the amplitude of heart rate oscillations suggest that high amplitude physiological oscillations have a causal impact on emotional well-being. Because blood flow timing helps determine brain network structure and function, slow oscillations in heart rate have the potential to strengthen brain network dynamics, especially in medial prefrontal regulatory regions that are particularly sensitive to physiological oscillations.

Trait hostility and cortisol sensitivity following a stressor: The moderating role of stress-induced heart rate variability

Hostility and adverse health outcomes are inconsistently associated in the literature. Self-regulation and cortisol secretion may play important roles in differentiating those hostile individuals who are at greater risk of negative health outcomes from those who are not. In the present study, we sought to examine if having high self-regulatory strength, as indexed by high stress-induced high-frequency heart rate variability (HF-HRV), buffered the effects of hostility on cortisol secretion. Participants (N=213) completed a self-report measure of hostility and measurement of HF-HRV at rest and during a social stress task. Saliva samples were collected immediately before (one sample), and over a 50min period after (six samples), the stress task to evaluate cortisol secretion over time. Hostile individuals were less likely to demonstrate cortisol sensitivity (i.e., high change in cortisol over time) when they had high stress-induced HF-HRV. Such findings are important given that cortisol sensitivity increases risk of metabolic and inflammatory disorders via glucocorticoid resistance and inflammation. Therefore, interventions that increase stress-induced HF-HRV may reduce the impact of hostility on health outcomes.

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.