Heart rate variability biofeedback: how and why does it work?

The effect of a single-session heart rate variability biofeedback on attentional control: does stress matter?

Introduction

Vagally mediated heart rate variability is an index of autonomic nervous system activity that is associated with a large variety of outcome variables including psychopathology and self-regulation. While practicing heart rate variability biofeedback over several weeks has been reliably associated with a number of positive outcomes, its acute effects are not well known. As the strongest association with vagally mediated heart rate variability has been found particularly within the attention-related subdomain of self-regulation, we investigated the acute effect of heart rate variability biofeedback on attentional control using the revised Attention Network Test.

Methods

Fifty-six participants were tested in two sessions. In one session each participant received a heart rate variability biofeedback intervention, and in the other session a control intervention of paced breathing at a normal ventilation rate. After the biofeedback or control intervention, participants completed the Attention Network Test using the Orienting Score as a measure of attentional control.

Results

Mixed models revealed that higher resting baseline vagally mediated heart rate variability was associated with better performance in attentional control, which suggests more efficient direction of attention to target stimuli. There was no significant main effect of the intervention on attentional control. However, an interaction effect indicated better performance in attentional control after biofeedback in individuals who reported higher current stress levels.

Discussion

The results point to acute beneficial effects of heart rate variability biofeedback on cognitive performance in highly stressed individuals. Although promising, the results need to be replicated in larger or more targeted samples in order to reach stronger conclusions about the effects.

Prognostic role of short-term heart rate variability and deceleration/acceleration capacities of heart rate in extensive-stage small cell lung cancer

Background: Prior research suggests that autonomic modulation investigated by heart rate variability (HRV) might act as a novel predictive biomarker for cancer prognosis, such as in breast cancer and pancreatic cancer. It is not clear whether there is a correlation between autonomic modulation and prognosis in patients with extensive-stage small cell lung cancer (ES-SCLC). Therefore, the purpose of the study was to examine the association between short-term HRV, deceleration capacity (DC) and acceleration capacity (AC) of heart rate and overall survival in patients with ES-SCLC. Methods: We recruited 40 patients with ES-SCLC, and 39 were included in the final analysis. A 5-min resting electrocardiogram of patients with ES-SCLC was collected using a microelectrocardiogram recorder to analyse short-term HRV, DC and AC. The following HRV parameters were used: standard deviation of the normal-normal intervals (SDNN) and root mean square of successive interval differences (RMSSD). Overall survival of patients with ES-SCLC was defined as time from the date of electrocardiogram measurement to the date of death or the last follow-up. Follow-up was last performed on 07 June 2023. There was a median follow-up time of 42.2 months. Results: Univariate analysis revealed that the HRV parameter SDNN, as well as DC significantly predicted the overall survival of ES-SCLC patients (all p < 0.05). Multivariate analysis showed that the HRV parameters SDNN (hazard ratio = 5.254, 95% CI: 1.817-15.189, p = 0.002), RMSSD (hazard ratio = 3.024, 95% CI: 1.093-8.372, p = 0.033), as well as DC (hazard ratio = 3.909, 95% CI: 1.353-11.293, p = 0.012) were independent prognostic factors in ES-SCLC patients. Conclusion: Decreased HRV parameters (SDNN, RMSSD) and DC are independently associated with shorter overall survival in ES-SCLC patients. Autonomic nervous system function (assessed based on HRV and DC) may be a new biomarker for evaluating the prognosis of patients with ES-SCLC.

Ancient medicine for a modern disease: traditional Amazonian medicine to treat substance use disorders

Background: There exists an underexploited opportunity to develop innovative therapeutic approaches to SUDs based upon the complementarity between modern and traditional health systems.Objectives: Illustrate the feasibility and potentiality of such an approach through the comprehensive description of Takiwasi Center's treatment model and program, where health concepts and practices from traditional Amazonian medicine work synergistically with modern psychotherapy and medicine in an intercultural dialog to assist in the rehabilitation of people suffering from SUDs.Methods: The description was built from a review of the literature, institutional data, participatory observation and unstructured interviews with staff, researchers and patients during treatment.Results: Since the foundation of the Takiwasi Center in 1992 in the peruvian Amazon, more than a thousand patients with different socio-cultural, ethnic and religious backgrounds have received residential treatment. We present how traditional Amazonian medicine techniques and health concepts cooperate to complement modern psychology in a therapeutic community setting and propose some hypotheses about the neurobiological, psycho-emotional and spiritual healing mechanisms triggered by the program to help people identify and heal the roots of their substance misuse and addictive behavior. We also summarize quantitative outcomes during treatment showing significant improvements in a wide variety of mental health indicators.Conclusion: Takiwasi Center's program is an option for people seeking non-conventional treatment who are sensitive to traditional Amazonian medicine practices and ready to explore the roots of their addiction. From this intercultural approach, some lessons could emerge toward a broader understanding of SUDs that may result in better patient care.

The Effectiveness of A Slow-Paced Diaphragmatic Breathing Exercise in Children's Daily Life: A Micro-Randomized Trial

OBJECTIVE

Breathing exercises have been proposed as an effective intervention to improve subjective well-being and manage anxiety symptoms. As they are comparatively easy to learn and to implement, breathing exercises may be particularly beneficial for children. Although breathing exercises are ultimately supposed to provide salutary effects in individuals' everyday lives, immediate effects of breathing exercises in naturalistic contexts have received limited empirical attention. The purpose of this study was to examine immediate effects of slow-paced diaphragmatic breathing on negative affect as well as on relaxation in an ecologically valid setting. To that end, we conducted a micro-randomized trial in children's daily life.

METHOD

On each of 15 days, children (N = 171, aged 9-13 years, 54% female) were randomized to different conditions: performing a video-guided slow-paced diaphragmatic breathing exercise (experimental condition), watching a different video (active control condition), or a passive control condition.

RESULTS

The breathing exercise had no immediate effects on negative affect or relaxation compared to both control conditions. However, in situations when children reported higher levels of worries than usual, relaxation was higher when children performed the breathing exercise compared to the passive control condition. Compared to the active control condition, the breathing exercise did not result in higher levels of relaxation in situations when children worried more than normally.

CONCLUSIONS

Findings highlight that context-specific factors can modulate the effectiveness of breathing exercises and should be taken into account to tailor interventions to individuals' needs.

Comparing two relaxation procedures to ease fatigue in multiple sclerosis: a single-blind randomized controlled trial

BACKGROUND

Various relaxation procedures have been proposed to reduce fatigue in multiple sclerosis (MS). However, it is unknown, which type of relaxation has the largest effect on fatigue reduction and on autonomic nervous system (ANS) activity.

OBJECTIVE

We aimed to compare two biofeedback-supported relaxation exercises: a deep breathing (DB) exercise and progressive muscle relaxation (PMR), which may ameliorate MS fatigue and alter ANS activity.

METHODS

We performed a single-blind randomized clinical trial, introducing MS patients (n = 34) to the DB or PMR exercise. We first tested cardiovagal integrity, reflected by changes in heart rate variability (HRV) in response to DB. Participants then performed a fatigue-inducing vigilance task, followed by the DB or PMR. State fatigue was recorded consecutively at baseline, after the vigilance task, and after the relaxation exercise, along with HRV reflecting ANS activity.

RESULTS

Only patients assigned to the PMR group experienced a significant drop in fatigue, whereas both relaxation exercises changed ANS activity. MS patients showed the expected autonomic response during the cardiovagal reflex test. The vigilance task elevated short-term feelings of fatigue and significantly reduced HRV parameters of parasympathetic activity. Trait fatigue was negatively correlated with HRV during the second half of the vigilance task.

CONCLUSION

PMR alleviates short-term feelings of fatigue in persons with MS. The vigilance task in combination with HRV measurements may be helpful for evaluating relaxation procedures as a treatment of fatigue. Hereby, future studies should ensure longer and more frequent relaxation exercises and focus on patients with weak to moderate fatigue.

TRIAL REGISTRATION

Trial Registry: DRKS00024358.

Daily heart rate variability biofeedback training decreases locus coeruleus MRI contrast in younger adults in a randomized clinical trial

As an arousal hub region in the brain, the locus coeruleus (LC) has bidirectional connections with the autonomic nervous system. Magnetic resonance imaging (MRI)-based measures of LC structural integrity have been linked to cognition and arousal, but less is known about factors that influence LC structure and function across time. Here, we tested the effects of heart rate variability (HRV) biofeedback, an intervention targeting the autonomic nervous system, on LC MRI contrast and sympathetic activity. Younger and older participants completed daily HRV biofeedback training for five weeks. Those assigned to an experimental condition performed biofeedback involving slow, paced breathing designed to increase heart rate oscillations, whereas those assigned to a control condition performed biofeedback to decrease heart rate oscillations. At the pre- and post-training timepoints, LC contrast was assessed using turbo spin echo MRI scans, and RNA sequencing was used to assess cAMP-responsive element binding protein (CREB)-regulated gene expression in circulating blood cells, an index of sympathetic nervous system signaling. We found that left LC contrast decreased in younger participants in the experimental group, and across younger participants, decreases in left LC contrast were related to the extent to which participants increased their heart rate oscillations during training. Furthermore, decreases in left LC contrast were associated with decreased expression of CREB-associated gene transcripts. On the contrary, there were no effects of biofeedback on LC contrast among older participants in the experimental group. These findings provide novel evidence that in younger adults, HRV biofeedback involving slow, paced breathing can decrease both LC contrast and sympathetic nervous system signaling.

PhysioKit: An Open-Source, Low-Cost Physiological Computing Toolkit for Single- and Multi-User Studies

The proliferation of physiological sensors opens new opportunities to explore interactions, conduct experiments and evaluate the user experience with continuous monitoring of bodily functions. Commercial devices, however, can be costly or limit access to raw waveform data, while low-cost sensors are efforts-intensive to setup. To address these challenges, we introduce PhysioKit, an open-source, low-cost physiological computing toolkit. PhysioKit provides a one-stop pipeline consisting of (i) a sensing and data acquisition layer that can be configured in a modular manner per research needs, and (ii) a software application layer that enables data acquisition, real-time visualization and machine learning (ML)-enabled signal quality assessment. This also supports basic visual biofeedback configurations and synchronized acquisition for co-located or remote multi-user settings. In a validation study with 16 participants, PhysioKit shows strong agreement with research-grade sensors on measuring heart rate and heart rate variability metrics data. Furthermore, we report usability survey results from 10 small-project teams (44 individual members in total) who used PhysioKit for 4-6 weeks, providing insights into its use cases and research benefits. Lastly, we discuss the extensibility and potential impact of the toolkit on the research community.

Using the Research Domain Criteria as a framework to integrate psychophysiological findings into stress management and psychotherapy interventions

Research on the psychophysiology of stress is expanding rapidly, but the field lacks a clear integrative framework to help translate research findings into empirically supported stress interventions. The Research Domain Criteria (RDoC) is an excellent candidate to explore as a framework to integrate stress research. The RDoC framework is a dimensional, multi-modal approach to psychopathology proposed as an alternative to categorical approaches used by the International Classification of Diseases (ICD) and the Diagnostic and Statistical Manual (DSM). The goal of this paper is to explore the RDoC as a framework to integrate psychophysiology research into therapeutic interventions for stress. The RDoC consists of six domains: negative valence systems, positive valence systems, cognitive systems, social processes systems, arousal/regulatory systems, and sensorimotor systems, and provides an excellent structure for integrating information from multiple levels of functioning including physiology, behavior, and self-report, as well as genes, molecules, cells, and brain circuits. Integrating psychophysiological research on stress using the RDoC framework can direct and amplify stress management and psychotherapeutic interventions. First, the RDoC provides a clear foundation for conceptualizing the stress response in terms of important concepts such as allostasis and adaptation. In this perspective, the terms "allostatic response" or "adaptation response" are more descriptive terms than "stress response" in understanding bodily responses to life threats and challenges. Second, psychophysiological approaches can be used in the context of modalities such as biofeedback and mindfulness to both collect psychophysiological data and then integrate that data into a broader therapeutic framework. Heart rate variability (HRV) biofeedback is being used more frequently as part of a therapeutic intervention package with stress management and psychotherapy, and HRV data is also used to provide outcome evidence on the efficacy of treatment. Mindfulness practices are commonly used in combination with stress management and psychotherapy, and psychophysiological data (HRV, EEG, blood pressure, etc.) is often collected to explore and understand mind/body relationships. In conclusion, the lack of a clear framework to assess and understand mind/body functioning limits current stress research and interventions. The RDoC provides a strong framework to assess and integrate physiological and psychological data and improve stress interventions.

Expiratory-gated Transcutaneous Auricular Vagus Nerve Stimulation (taVNS) does not Further Augment Heart Rate Variability During Slow Breathing at 0.1 Hz

As cardiac vagal control is a hallmark of good health and self-regulatory capacity, researchers are seeking ways to increase vagally mediated heart rate variability (vmHRV) in an accessible and non-invasive way. Findings with transcutaneous auricular vagus nerve stimulation (taVNS) have been disappointing in this respect, as its effects on vmHRV are inconsistent at best. It has been speculated that combining taVNS with other established ways to increase vmHRV may produce synergistic effects. To test this idea, the present study combined taVNS with slow breathing in a cross-over design. A total of 22 participants took part in two sessions of breathing at 6 breaths/min: once combined with taVNS, and once combined with sham stimulation. Electrical stimulation (100 Hz, 400 µs) was applied during expiration, either to the tragus and cavum conchae (taVNS) or to the earlobe (sham). ECG was recorded during baseline, 20-minutes of stimulation, and the recovery period. Frequentist and Bayesian analyses showed no effect of taVNS (in comparison to sham stimulation) on the root mean square of successive differences between normal heartbeats, mean inter-beat interval, or spectral power of heart rate variability at a breathing frequency of 0.1 Hz. These findings suggest that expiratory-gated taVNS combined with the stimulation parameters examined here does not produce acute effects on vmHRV during slow breathing.

Is Biofeedback for Vertigo Effective in Ordinary Medical Centers? A Controlled Trial in Northern Italy

The aim of this study was to assess the therapeutic effectiveness of biofeedback, in a medical center's routine for treating vestibular disorders, reducing emotional, functional, and physical disability at three-month follow-up. A total of 197 outpatients were recruited from a medical center to treat vestibular disorders. Patients in the control group received treatment as usual, consisting of one monthly visit with an otolaryngologist and pharmacological treatment specific for vertigo, while the experimental group attended biofeedback training. Patients in the experimental group received pharmacological therapy only in the phase before the start of biofeedback in order to stabilize the acute phase. During the three-month follow-up, the experimental group did not receive any booster sessions of biofeedback. At three-month follow-up there was a statistically significant difference between the groups, both in the mean total score of the dizziness handicap inventory and in the three subscales: physical, emotional, and functional. Moreover, the biofeedback group had reduced psycho-physiological parameters for all average values at three-month follow-up compared to the baseline. This is one of few studies assessing the effectiveness of biofeedback in a naturalistic setting for vestibular disorder treatment. The data confirmed that biofeedback can impact illness course, in terms of self-perceived disability reduction, assessed on emotional, functional, and physical aspects of daily living.

Silence and its effects on the autonomic nervous system: A systematic review

This systematic review explores the influence of silence on the autonomic nervous system. The Polyvagal Theory has been used as a reference model to describe the autonomic nervous system by explaining its role in emotional regulation, social engagement, and adaptive physiological responses. PubMed, Scopus, PsycInfo, EMBASE, and Google Scholar were systematically searched up until July 2023 for relevant studies. The literature search yielded 511 results, and 37 studies were eventually included in this review. Silence affects the autonomic nervous system differently based on whether it is inner or outer silence. Inner silence enhances activity of the ventral vagus, favoring social engagement, and reducing sympathetic nervous system activity and physiological stress. Outer silence, conversely, can induce a heightened state of alertness, potentially triggering vagal brake removal and sympathetic nervous system activation, though with training, it can foster inner silence, preventing such activation. The autonomic nervous system response to silence can also be influenced by other factors such as context, familiarity with silence, presence and quality of outer noise, and empathy.

A Pilot Study of the Biofeedback Training to Reduce Salivary Cortisol Level and Improve Mental Health in Highly-Trained Female Athletes

Biofeedback (BFB) training can provide a useful resource for athletes to cope with stress. However, the effects of BFB training on acute and chronic endocrine stress responses, parasympathetic activity, and mental health in competitive athletes have not been explored yet. This pilot study examined the effects of a 7-week BFB training on psychophysiological parameters in highly trained female athletes. Six highly trained female volleyball players (mean age: 17.50 ± 1.05 years) volunteered to participate in the study. Athletes individually attended 21-session heart rate variability (HRV)-BFB training consisting of six minutes for 7 weeks. A BFB device (Nexus 10) was used to measure the athletes' physiological responses reflecting HRV. To assess the cortisol awakening response (CAR), saliva samples were collected immediately after awakening and 15 min, 30 min, and 60 min post-awakening. The Depression Anxiety Stress Scale-21 was filled out before and after the intervention to assess mental health. Furthermore, athletes provided saliva samples during eight sessions pre- and immediately post-session. Mid-day cortisol levels decreased significantly after the intervention. No significant change was observed in CAR and physiological responses after the intervention. A significant decrease in cortisol level was observed in BFB sessions in which cortisol level was assessed, except for two sessions. We concluded that short sessions of 7-week HRV-BFB training could be used as an effective method to control autonomic functions and stress of female athletes. Although the present study provides strong evidence for the psychophysiological well-being of athletes, further investigations with larger samples are needed.

Methods for Heart Rate Variability Biofeedback (HRVB): A Systematic Review and Guidelines

Heart Rate Variability Biofeedback (HRVB) has been widely used to improve cardiovascular health and well-being. HRVB is based on breathing at an individual's resonance frequency, which stimulates respiratory sinus arrhythmia (RSA) and the baroreflex. There is, however, no methodological consensus on how to apply HRVB, while details about the protocol used are often not well reported. Thus, the objectives of this systematic review are to describe the different HRVB protocols and detect methodological concerns. PsycINFO, CINALH, Medline and Web of Science were searched between 2000 and April 2021. Data extraction and quality assessment were based on PRISMA guidelines. A total of 143 studies were finally included from any scientific field and any type of sample. Three protocols for HRVB were found: (i) "Optimal RF" (n = 37), each participant breathes at their previously detected RF; (ii) "Individual RF" (n = 48), each participant follows a biofeedback device that shows the optimal breathing rate based on cardiovascular data in real time, and (iii) "Preset-pace RF" (n = 51), all participants breathe at the same rate rate, usually 6 breaths/minute. In addition, we found several methodological differences for applying HRVB in terms of number of weeks, duration of breathing or combination of laboratory and home sessions. Remarkably, almost 2/3 of the studies did not report enough information to replicate the HRVB protocol in terms of breathing duration, inhalation/exhalation ratio, breathing control or body position. Methodological guidelines and a checklist are proposed to enhance the methodological quality of future HRVB studies and increase the information reported.

The Effect of a Biofeedback-Based Integrated Program on Improving Orthostatic Hypotension in Community-Dwelling Older Adults: A Pilot Study

BACKGROUND

Orthostatic hypotension (OH) is prevalent among community-dwelling older adults and is associated with multiple negative health outcomes. Older adults are susceptible to developing OH because aging alters autonomic nervous system function. Biofeedback is a noninvasive, nonpharmacological intervention that can modulate autonomic nervous system dysfunction in older adults.

OBJECTIVES

Our aim in this study was to examine the effect of a biofeedback-based integrated program on community-dwelling older adults with OH.

METHODS

We conducted a controlled pilot study. Community-dwelling older adults 65 years or older who had nonneurogenic OH were eligible. Data from 51 participants, comprising 27 in the intervention group and 24 in the control group, were analyzed. Weekly biofeedback-based integrated program consisting of biofeedback training along with group education about behavioral modification, physical activities, and telephone counseling was provided for 12 weeks. Orthostatic hypotension was evaluated by measuring the drop in systolic and diastolic blood pressure after postural changes. Autonomic nervous system function was measured using heart rate variability.

RESULTS

Among the indicators of heart rate variability, total power (P = .037) and low frequency (P = .017) increased significantly, suggesting that autonomic function improved. Severity of orthostatic symptoms (P < .001) and drops in systolic (P = .003) and diastolic (P = .012) blood pressure after postural changes decreased significantly in the intervention group.

CONCLUSION

Biofeedback-based integrated program was effective in improving autonomic nervous system function and alleviated OH. Therefore, biofeedback-based integrated program should be tested in a larger randomized controlled study with long-term follow-up.

The Future of Stress Management: Integration of Smartwatches and HRV Technology

In the modern world, stress has become a pervasive concern that affects individuals' physical and mental well-being. To address this issue, many wearable devices have emerged as potential tools for stress detection and management by measuring heart rate, heart rate variability (HRV), and various metrics related to it. This literature review aims to provide a comprehensive analysis of existing research on HRV tracking and biofeedback using smartwatches pairing with reliable 3rd party mobile apps like Elite HRV, Welltory, and HRV4Training specifically designed for stress detection and management. We apply various algorithms and methodologies employed for HRV analysis and stress detection including time-domain, frequency-domain, and non-linear analysis techniques. Prominent smartwatches, such as Apple Watch, Garmin, Fitbit, Polar, and Samsung Galaxy Watch, are evaluated based on their HRV measurement accuracy, data quality, sensor technology, and integration with stress management features. We describe the efficacy of smartwatches in providing real-time stress feedback, personalized stress management interventions, and promoting overall well-being. To assist researchers, doctors, and developers with using smartwatch technology to address stress and promote holistic well-being, we discuss the data's advantages and limitations, future developments, and the significance of user-centered design and personalized interventions.

A meta-analysis investigating the outcomes and correlation between heart rate variability biofeedback training on depressive symptoms and heart rate variability outcomes versus standard treatment in comorbid adult populations

BACKGROUND AND AIM

Heart rate variability biofeedback (HRVB) has previously been used to ameliorate depressive symptoms but its uses for tackling depressive symptoms in an array of comorbid adult patients is less established. This meta-analysis aims to evaluate whether HRVB is a useful tool to reduce depressive symptoms and improve HRV relative to standard treatment in adult comorbid populations, while also attempting to establish the association between the two outcomes.

METHODS

An extensive literature review was conducted using several databases including PubMed, Cinahl, Medline, Web of science and clinical.gov/UK register. A total of 149 studies were identified with 9 studies, totalling 428 participants were analysed using a random effects model.

RESULTS

Depressive outcomes yielded a mean effect size g=0.478 (CI 95% 0.212, 0.743) with HRV outcomes, yielding a mean effect size of g=0.223 (95% CI 0.036 to 0.411). Total heterogeneity was non-significant for depressive outcomes (Q= 13.77, p=0.088 I^=42.86%) and HRV (Q= 1.598, p=0.991, I^=0.000%) which indicates that little variance existed for the included studies.

CONCLUSIONS

In summary, the outcomes demonstrate that HRVB can improve both clinically relevant depressive symptoms and physiological HRV outcomes in various comorbid conditions in adult populations, while the correlation between the two was moderately negative, but non-significant.

Dataset used to refine a treatment protocol of a biofeedback-based virtual reality intervention for pain and anxiety in children and adolescents undergoing surgery

There is a great need for nonpharmacologic pain management strategies, given the catastrophic effects of the opioid epidemic and the role of opioid prescription in precipitating addiction [1], particularly in children and adolescents at risk of chronic pain and opioid use after surgery [2], [3], [4]. Biofeedback-based virtual reality (VR-BF) is an innovative approach to managing pain that compliments and may even increase accessibility [5] and acceptability [6] of existing mind-body therapies for pain management, like biofeedback (BF). BF teaches patients behavioral modification techniques that impact involuntary processes [7,8]. For example, slow breathing increases heart rate variability (HRV) [9] to reduce pain through the downregulation of the sympathetic nervous system [10,11]. However, barriers to widespread use, such as the need for trained personnel and high costs of direct intervention, have hindered its widespread clinical use and access to this therapy [5,12]. VR-BF has not yet been integrated into perioperative care, and as such, no defined treatment protocols for preoperative training and postoperative application of VR-BF exist, particularly in children. The dataset presented in this article may help fill the unmet, critical need for accessible, effective, alternative therapeutic options for reducing postoperative pain and opioid exposure in children. This investigation aimed to establish measurable outcomes impacting a perioperative treatment protocol of VR-BF, a novel VR-based therapy that teaches patients relaxation techniques and monitors the sensitivity of heart rate variability (HRV) to different frequencies and durations of VR-BF sessions. Achievement of target physiological parameters, including HRV, was measured in children and adolescents undergoing surgery anticipated to cause moderate to severe pain (e.g., orthopedic, chest) requiring postoperative pain management by the Acute Pain Services at Nationwide Children's Hospital (NCH). This dataset included 23 surgical patients evaluated quantitatively and qualitatively to refine a treatment protocol for the feasibility and acceptability of (a) preoperative education and training in relaxation, and (b) postoperative application of a VR-BF intervention for pain management [13]. Qualitative data was collected using an investigator-derived questionnaire to obtain feedback and understand the patient and family experience using VR-BF. Descriptive statistics (mean±SD or median with interquartile range [IQR] for continuous variables; frequencies and percentages for categorical variables) and exploratory spline regression analyses were generated to define measurable outcomes for a future pilot, randomized clinical trial protocol.

Impact of virtual adjunctive cognitive remediation therapy on cognitive flexibility and treatment outcomes in comorbid anorexia nervosa and exercise dependence as quantified using novel biomarkers: A stage 1 registered report

OBJECTIVE

Anorexia nervosa (AN) is associated with significant individual mental and physical suffering and public health burden and fewer than half of patients recover fully with current treatments. Comorbid exercise dependence (ExD) is common in AN and associated with significantly worse symptom severity and treatment outcomes. Research points to cognitive inflexibility as a prominent executive function inefficiency and transdiagnostic etiologic and maintaining mechanism linking AN and ExD. This study will evaluate the initial efficacy of adjunctive Cognitive Remediation Therapy (CRT), which has been shown to produce cognitive improvements in adults with AN, in targeting cognitive inflexibility in individuals with comorbid AN and ExD. As an exploratory aim, this study also addresses the current lack of quick and cost-effective assessments of cognitive flexibility by establishing the utility of two proposed biomarkers, heart rate variability and salivary oxytocin.

METHOD

We will conduct a single-group, within-subjects trial of an established CRT protocol delivered remotely as an adjunct to inpatient or intensive outpatient treatment as usual (TAU) to adult patients (n = 42) with comorbid AN and ExD. Assessments, including self-report, neuropsychological, and biomarker measurements, will occur at three time points.

RESULTS

We expect CRT to increase cognitive flexibility transdiagnostically and consequently, along with TAU, positively impact AN and ExD compulsivity and symptom severity, including weight gain.

DISCUSSION

Findings will inform the development of more effective integrative interventions for AN and ExD targeting shared mechanisms and facilitate the routine assessment of cognitive flexibility as a transdiagnostic risk and maintaining factor across psychopathologies in clinical and research settings.

PUBLIC SIGNIFICANCE

Patients with anorexia nervosa often engage in excessive exercise, leading to harmful outcomes, including increased suicidal behavior. This study examines the preliminary efficacy of an intervention that fosters flexible and holistic thinking in patients with problematic eating and exercise to, along with routine treatment, decrease harmful exercise symptoms. This study also examines new biological markers of the inflexible thinking style thought to be characteristic of anorexia nervosa and exercise dependence.

Asynchronous Heart Rate Variability Biofeedback Protocol Effects on Adolescent Athletes' Cognitive Appraisals and Recovery-Stress States

This study examined the effect of an asynchronous heart rate variability biofeedback (HRV-BFBasync) protocol on national-level adolescent swimmers' cognitive appraisals and recovery-stress states during a six-week ecological training period. A polynomial mixed-effects multilevel regression analysis approach was used with 27 adolescent national-level swimmers randomly assigned to an intervention group (n = 14) and a control group (n = 13). Six waves of assessments of cognitive appraisals and recovery-stress states were completed during six weeks of training preparation in ecological conditions. The results revealed that the HRV-BFBasync protocol significantly predicts lower levels of biopsychosocial stress states and cognitive stress. However, no significant effects were found for biopsychosocial recovery scales and cognitive perceived control. The results suggested that total stress states, sport-specific stress, and cognitive perceived stress evolutions are a function of polynomial time third-degree interactions with HRV-BFB protocol. Overall, this study suggested that the HRV-BFBasync protocol leads adolescent athletes to experience lower biopsychosocial and cognitive stress levels during training periodization. Our results also suggest that HRV-BFB induces complex evolutions over time for stress and recovery states but does not have a predictive function for the recovery states and perceived control.

Induced Relaxation Enhances the Cardiorespiratory Dynamics in COVID-19 Survivors

Most COVID-19 survivors report experiencing at least one persistent symptom after recovery, including sympathovagal imbalance. Relaxation techniques based on slow-paced breathing have proven to be beneficial for cardiovascular and respiratory dynamics in healthy subjects and patients with various diseases. Therefore, the present study aimed to explore the cardiorespiratory dynamics by linear and nonlinear analysis of photoplethysmographic and respiratory time series on COVID-19 survivors under a psychophysiological assessment that includes slow-paced breathing. We analyzed photoplethysmographic and respiratory signals of 49 COVID-19 survivors to assess breathing rate variability (BRV), pulse rate variability (PRV), and pulse-respiration quotient (PRQ) during a psychophysiological assessment. Additionally, a comorbidity-based analysis was conducted to evaluate group changes. Our results indicate that all BRV indices significantly differed when performing slow-paced breathing. Nonlinear parameters of PRV were more appropriate for identifying changes in breathing patterns than linear indices. Furthermore, the mean and standard deviation of PRQ exhibited a significant increase while sample and fuzzy entropies decreased during diaphragmatic breathing. Thus, our findings suggest that slow-paced breathing may improve the cardiorespiratory dynamics of COVID-19 survivors in the short term by enhancing cardiorespiratory coupling via increased vagal activity.

Acute effect of breathing exercises on muscle tension and executive function under psychological stress

Introduction

Intensive and long-lasting office work is a common cause of muscular and mental disorders due to workplace stressors. Mindful and slow breathing exercises decrease psychological stress and improve mental health, whereas fast breathing increases neuronal excitability. This study aimed to explore the influence of 5 min of mindful breathing (MINDFUL), slow breathing (SLOW), fast breathing (FAST), and listening to music (MUSIC) on muscle tension and executive function during an intensive psychological task.

Methods

Forty-eight participants (24 men and 24 women) were enrolled. Muscle tension was recorded using surface electromyography, and executive function was assessed using the Stroop Color and Word Test (Stroop Test). The respiration rate (RR), oxygen saturation (SpO₂), end-tidal carbon dioxide (EtCO₂), and the subjects' preferred method were also recorded. During the experiment, participants performed a one-time baseline test (watching a neutral video for 5 min) and then completed 5 min of MUSIC, MINDFUL, SLOW, and FAST in a random sequence. The Stroop Test was performed after each intervention, including the baseline test, and was followed by a 5 min rest before performing the next intervention.

Results

None of the methods significantly influenced muscular activity and performance of the Stroop Test in both men and women, based on the average 5 min values. However, at the fifth minute, men's accuracy rate in the Stroop Test was significantly higher after SLOW than after MUSIC and FAST, and the reaction time after the SLOW was the shortest. SpO₂ was significantly higher during SLOW than during MUSIC, and RR was relatively lower after SLOW than after MUSIC. Most men preferred SLOW, and most women preferred MUSIC, whereas FAST was the most unfavorable method for both men and women.

Conclusion

Brief breathing exercises did not substantially affect muscle tension under psychological stress. SLOW demonstrated greater potential for sustaining executive function in men, possibly via its superior respiration efficiency on SpO₂ and inhibition of RR.

Guiding Breathing at the Resonance Frequency with Haptic Sensors Potentiates Cardiac Coherence

Cardiac coherence is a state achieved when one controls their breathing rate during the so-called resonance frequency breathing. This maneuver allows respiratory-driven vagal modulations of the heart rate to superimpose with sympathetic modulations occurring at 0.1 Hz, thereby maximizing autonomous power in heart-to-brain connections. These stimulations have been shown to improve vagal regulations, which results in obvious benefits for both mental and organic health. Here, we present a device that is able to deliver visual and haptic cues, as well as HRV biofeedback information to guide the user in maintaining a 0.1 Hz breathing frequency. We explored the effectiveness of cardiac coherence in three guidance conditions: visual, haptic and visuo-haptic breathing. Thirty-two healthy students (sixteen males) were divided into three groups that experienced five minutes of either visual, haptic and visuo-haptic guided breathing at 0.1 Hz. The effects of guidance on the (adequate) breathing pattern and heart rate variability (HRV) were analyzed. The interest of introducing haptic breathing to achieve cardiac coherence was shown in the haptic and visuo-haptic groups. Especially, the P_0.1 index, which indicates how the autonomous power is 'concentrated' at 0.1 Hz in the PSD spectrum, demonstrated the superiority of combining haptic with visual sensory inputs in potentiating cardiac coherence (0.55 ± 0.20 for visuo-haptic vs. 0.28 ± 0.14 for visual only guidance; p < 0.05) haptic-induced effectiveness could be an asset for a more efficient and time-saving practice, allowing improved health and well-being even under tight time constraints.

Effects of heart rate variability biofeedback (HRVBFB) on sleep quality and depression among methamphetamine users

Methamphetamine is garnering concern due to its increasing use worldwide. Depression and sleep quality are major mental health issues in substance users. Heart rate variability biofeedback (HRVBFB) has shown promising results in terms of reducing depression and increasing sleep quality. The present study aimed to explore the effects of HRVBFB on these two issues in methamphetamine users. Sixty-one methamphetamine users were enrolled and allocated randomly into a treatment as usual (TAU) group and a HRVBFB plus TAU group. The levels of depressive symptoms and sleep quality were assessed at intake, end of the intervention, and end of follow-up. Compared with baseline, the levels of depressive symptoms and poor sleep quality were decreased at the end of the intervention and follow-up in the HRVBFB group. The HRVBFB group exhibited a greater decrease in depressive symptoms and a better improvement in sleep quality than the TAU group. The associations of HRV indices with levels of depressive symptoms and poor sleep quality were different in the two groups. Our results showed that HRVBFB is a promising intervention for reducing depressive symptoms and improving sleep quality in methamphetamine users. The benefits with respect to depressive symptoms and poor sleep quality can extend beyond the end of HRVBFB intervention.

Effect of Various Lengths of Respiration on Heart Rate Variability during Simple Bhramari (Humming)

Background

Heart rate varies during breathing and the heart rate variability (HRV) facilitates the autonomic homeostatic capacity. The maximum HRV was observed at around 10 s of prolonged respiration as per HRV biofeedback literature. However, there is a gap in understanding the variations in HRV by different respiration lengths during simple Bhramari practice.

Objective

To assess the effect of various respiration lengths (8, 10, 12, and 14 s) on HRV during the simple Bhramari (humming) practice.

Methodology

A total of 118 individuals (67 males, 51 females) signed up for the study based on convenience sampling at a wellness center. A randomized (simple permutation) within-subject crossover design with repeated measures was used to measure their HRV during the simple Bhramari practice. The results were analyzed with one-way ANOVA and paired samples t-test.

Results

The results indicate that, unlike the 10 s of respiration during HRV biofeedback breathing, maximum HRV during humming happens between 12 and 14 s of long breathing.

Conclusions

The unique findings of the study demonstrate the maximization of HRV between the respiration lengths of 12 and 14 s. Future work should explore expanding the research to a broader group of participants, including individuals with chronic conditions and other demographic variables and mantra chanting.

Humming (Simple Bhramari Pranayama) as a Stress Buster: A Holter-Based Study to Analyze Heart Rate Variability (HRV) Parameters During Bhramari, Physical Activity, Emotional Stress, and Sleep

Objective In this study, our goal was to understand the comparative impact of humming, physical activity, emotional stress, and sleep on several heart rate variability (HRV) parameters, including the stress index (SI), and to assess the effectiveness of humming (simple Bhramari) as a stress buster based on the HRV parameters. Methods This pilot study assessed the long-term HRV parameters of 23 participants in terms of four activities: humming (simple Bhramari), physical activity, emotional stress, and sleep. The single-channel Holter device measured the readings, and data was analyzed using Kubios HRV Premium software for time and frequency-domain HRV parameters, including the stress index. Regarding statistical analysis, single-factor ANOVA followed by paired t-test was used to compare the results of HRV parameters "during" the four activities to understand if humming generates the outcome to enhance the autonomic nervous system. Results Our findings revealed that humming generates the lowest stress index compared to all three other activities (physical activity, emotional stress, and sleep). Several additional HRV parameters also supported the positive impact on the autonomic nervous, equivalent to stress reduction. Conclusions Humming (simple Bhramari) can be an effective stress-buster based on the assessment of several HRV parameters during its practice and in comparison with other activities. A regular daily humming routine can help enhance the parasympathetic nervous system and slow down sympathetic activation.

Use of a Mobile Biofeedback Application to Provide Health Coaching for Stress Self-Management: Findings from a Pilot Quasi-Experiment

BACKGROUND

Mental health is an increasing concern among vulnerable populations, including college students and veterans.

OBJECTIVE

The purpose of this study was to determine if mobile Health (mHealth) technology combined with health coaching can better enable user to self-manage their mental health.

METHODS

This study evaluated a mobile Biofeedback app that provided health coaching on stress self-management for college student veterans' mental health concerns. Twenty-four college student veterans were recruited from a large public university in Texas during the spring 2020 semester, impacted by COVID-19. Ten participants were assigned to the intervention group where they used the mobile Biofeedback app on their smartphones and smartwatches, and 14 were assigned to the control group without the app; assignment was based on mobile phone compatibility. Both groups participated in one initial lab session where they learned a deep breathing exercise technique. The intervention group was then asked to use the mobile Biofeedback app during their daily lives using the Biofeedback app and smartwatch, and the control group was asked to perform the breathing exercises on their own. Both groups filled out Patient Health Questionnaire (PHQ-9) and Generalized Anxiety Disorder (GAD-7) self-assessments at two-week intervals. At the end of the semester, both groups were given an exit interview to provide user experience and perceived benefits of health coaching via the mobile Biofeedback app.

RESULTS

Deep breathing exercise in the initial lab session reduced stress in both groups. Over the course of the study, the app recorded 565 coached breathing exercises with a significant decrease (approximately 3 beats per minute) in participants' heart rate during the 6-minute time period immediately after conducting the breathing exercises [Spearman's rank correlation coefficient of -0.61 (P<.001 and S=9,816,176)]. There was no significant difference between the two groups for PHQ-9 and GAD-7 scores over the course of the semester. Exit interview responses indicate that participants perceived that the mobile Biofeedback app improved their health and helped them address stress challenges. All participants reported that the intervention helped them manage their stress better and expressed that health coaching via a mobile device would improve their overall health.

CONCLUSIONS

Participants reported a positive perception of the app for their mental health self-management during a stressful semester. Future work should examine long-term effects of the app with a larger sample size balanced between male and female participants, randomized participant allocation, real-time detection of mental health symptoms, and additional features of the app.

CLINICALTRIAL

Modulating heart rate oscillation affects plasma amyloid beta and tau levels in younger and older adults

Slow paced breathing via heart rate variability (HRV) biofeedback stimulates vagus-nerve pathways that counter noradrenergic stress and arousal pathways that can influence production and clearance of Alzheimer's disease (AD)-related proteins. Thus, we examined whether HRV biofeedback intervention affects plasma Αβ40, Αβ42, total tau (tTau), and phosphorylated tau-181 (pTau-181) levels. We randomized healthy adults (N = 108) to use slow-paced breathing with HRV biofeedback to increase heart rate oscillations (Osc+) or to use personalized strategies with HRV biofeedback to decrease heart rate oscillations (Osc-). They practiced 20-40 min daily. Four weeks of practicing the Osc+ and Osc- conditions produced large effect size differences in change in plasma Aβ40 and Aβ42 levels. The Osc+ condition decreased plasma Αβ while the Osc- condition increased Αβ. Decreases in Αβ were associated with decreases in gene transcription indicators of β-adrenergic signaling, linking effects to the noradrenergic system. There were also opposing effects of the Osc+ and Osc- interventions on tTau for younger adults and pTau-181 for older adults. These results provide novel data supporting a causal role of autonomic activity in modulating plasma AD-related biomarkers.Trial registration: NCT03458910 (ClinicalTrials.gov); first posted on 03/08/2018.

Nutritional and Behavioral Countermeasures as Medication Approaches to Relieve Motion Sickness: A Comprehensive Review

The mismatch in signals perceived by the vestibular and visual systems to the brain, also referred to as motion sickness syndrome, has been diagnosed as a challenging condition with no clear mechanism. Motion sickness causes undesirable symptoms during travel and in virtual environments that affect people negatively. Treatments are directed toward reducing conflicting sensory inputs, accelerating the process of adaptation, and controlling nausea and vomiting. The long-term use of current medications is often hindered by their various side effects. Hence, this review aims to identify non-pharmacological strategies that can be employed to reduce or prevent motion sickness in both real and virtual environments. Research suggests that activation of the parasympathetic nervous system using pleasant music and diaphragmatic breathing can help alleviate symptoms of motion sickness. Certain micronutrients such as hesperidin, menthol, vitamin C, and gingerol were shown to have a positive impact on alleviating motion sickness. However, the effects of macronutrients are more complex and can be influenced by factors such as the food matrix and composition. Herbal dietary formulations such as Tianxian and Tamzin were shown to be as effective as medications. Therefore, nutritional interventions along with behavioral countermeasures could be considered as inexpensive and simple approaches to mitigate motion sickness. Finally, we discussed possible mechanisms underlying these interventions, the most significant limitations, research gaps, and future research directions for motion sickness.

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.

Biofeedback as an Adjunct or Alternative Intervention to Cognitive Behavioral Therapy for Insomnia

Insomnia is highly prevalent and comorbid with many disorders. However, insomnia is underdiagnosed and undertreated in many populations. Cognitive behavioral therapy for insomnia (CBT-I) is not appropriate or sufficient for some individuals. Biofeedback has demonstrated efficacy in a range of disorders, including insomnia. The authors discuss the history and rationale for the use of biofeedback in the treatment of insomnia and other comorbid disorders. The article also presents current research on biofeedback for insomnia and comorbid disorders with recommendations for using biofeedback as an adjunct or alternative intervention to CBT-I.

Measuring the Effectiveness of a Multicomponent Program to Manage Academic Stress through a Resilience to Stress Index

In this work, we evaluate the effectiveness of a multicomponent program that includes psychoeducation in academic stress, mindfulness training, and biofeedback-assisted mindfulness, while enhancing the Resilience to Stress Index (RSI) of students through the control of autonomic recovery from psychological stress. Participants are university students enrolled in a program of excellence and are granted an academic scholarship. The dataset consists of an intentional sample of 38 undergraduate students with high academic performance, 71% (27) women, 29% (11) men, and 0% (0) non-binary, with an average age of 20 years. The group belongs to the "Leaders of Tomorrow" scholarship program from Tecnológico de Monterrey University, in Mexico. The program is structured in 16 individual sessions during an eight-week period, divided into three phases: pre-test evaluation, training program, and post-test evaluation. During the evaluation test, an assessment of the psychophysiological stress profile is performed while the participants undergo a stress test; it includes simultaneous recording of skin conductance, breathing rate, blood volume pulse, heart rate, and heart rate variability. Based on the pre-test and post-test psychophysiological variables, an RSI is computed under the assumption that changes in physiological signals due to stress can be compared against a calibration stage. The results show that approximately 66% of the participants improved their academic stress management after the multicomponent intervention program. A Welch's t-test showed a difference in mean RSI scores (t = -2.30, p = 0.025) between the pre-test and post-test phases. Our findings show that the multicomponent program promoted positive changes in the RSI and in the management of the psychophysiological responses to academic stress.

Breathwork Interventions for Adults with Clinically Diagnosed Anxiety Disorders: A Scoping Review

Anxiety disorders are the most common group of mental disorders, but they are often underrecognized and undertreated in primary care. Dysfunctional breathing is a hallmark of anxiety disorders; however, mainstays of treatments do not tackle breathing in patients suffering anxiety. This scoping review aims to identify the nature and extent of the available research literature on the efficacy of breathwork interventions for adults with clinically diagnosed anxiety disorders using the DSM-5 classification system. Using the PRISMA extension for scoping reviews, a search of PubMed, Embase, and Scopus was conducted using terms related to anxiety disorders and breathwork interventions. Only clinical studies using breathwork (without the combination of other interventions) and performed on adult patients diagnosed with an anxiety disorder using the DSM-5 classification system were included. From 1081 articles identified across three databases, sixteen were included for the review. A range of breathwork interventions yielded significant improvements in anxiety symptoms in patients clinically diagnosed with anxiety disorders. The results around the role of hyperventilation in treatment of anxiety were contradictory in few of the examined studies. This evidence-based review supports the clinical utility of breathwork interventions and discusses effective treatment options and protocols that are feasible and accessible to patients suffering anxiety. Current gaps in knowledge for future research directions have also been identified.

Increasing coordination and responsivity of emotion-related brain regions with a heart rate variability biofeedback randomized trial

Heart rate variability is a robust biomarker of emotional well-being, consistent with the shared brain networks regulating emotion regulation and heart rate. While high heart rate oscillatory activity clearly indicates healthy regulatory brain systems, can increasing this oscillatory activity also enhance brain function? To test this possibility, we randomly assigned 106 young adult participants to one of two 5-week interventions involving daily biofeedback that either increased heart rate oscillations (Osc+ condition) or had little effect on heart rate oscillations (Osc- condition) and examined effects on brain activity during rest and during regulating emotion. While there were no significant changes in the right amygdala-medial prefrontal cortex (MPFC) functional connectivity (our primary outcome), the Osc+ intervention increased left amygdala-MPFC functional connectivity and functional connectivity in emotion-related resting-state networks during rest. It also increased down-regulation of activity in somatosensory brain regions during an emotion regulation task. The Osc- intervention did not have these effects. In this healthy cohort, the two conditions did not differentially affect anxiety, depression, or mood. These findings indicate that modulating heart rate oscillatory activity changes emotion network coordination in the brain.

Feasibility and acceptability of perioperative application of biofeedback-based virtual reality versus active control for pain and anxiety in children and adolescents undergoing surgery: protocol for a pilot randomised controlled trial

INTRODUCTION

Current clinical applications of virtual reality (VR) provide patients with transient pain relief during acutely painful events by redirecting attention. Biofeedback (BF) is a mind-body therapy that effectively produces sustained pain reduction, but there are obstacles to its routine use. Combined, BF-based VR (VR-BF) may increase accessibility while enhancing the benefits of BF. VR-BF has yet to be employed in perioperative care, and as such, no defined treatment protocol for VR-BF exists. The primary aim of this study is to assess the feasibility of the perioperative use of VR-BF in children and adolescents. The secondary aims are to assess the acceptability of VR-BF and to collect pilot efficacy data.

METHODS AND ANALYSIS

This is a single-centre, randomised controlled pilot clinical trial. A total of 70 patients (12-18 years) scheduled for surgery anticipated to cause moderate to severe pain with ≥1 night of hospital admission will be randomised to one of two study arms (VR-BF or control). Participants randomised to VR-BF (n=35) will use the ForeVR VR platform to engage their breathing in gamified VR applications. Participants randomised to control (n=35) will interact with a pain reflection app, Manage My Pain. The primary outcome is feasibility of VR-BF use in adolescents undergoing surgery as assessed through recruitment, enrolment, retention and adherence to the protocol. Secondary outcomes are acceptability of VR-BF and pilot efficacy measures, including pain, anxiety and opioid consumption.

ETHICS AND DISSEMINATION

The protocol was approved by the Nationwide Children's Hospital Institutional Review Board (IRB #STUDY00002080). Patient recruitment begins in March 2023. Written informed consent is obtained for all participants. All information acquired will be disseminated via scientific meetings and published in peer-reviewed journals. Data will be available per request and results will be posted on ClinicalTrials.gov.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registry (NCT04943874).

Conscious connected breathing with breath retention intervention in adults with chronic low back pain: protocol for a randomized controlled pilot study

BACKGROUND

Chronic pain is a major source of human suffering, and chronic low back pain (cLBP) is among the most prevalent, costly, and disabling of pain conditions. Due to the significant personal and societal burden and the complex and recurring nature of cLBP, self-management approaches that can be practiced at home are highly relevant to develop and test. The respiratory system is one of the most integrated systems of the body, and breathing is bidirectionally related with stress, emotion, and pain. Thus, the widespread physiological and psychological impact of breathing practices and breathwork interventions hold substantial promise as possible self-management strategies for chronic pain. The primary aim of the current randomized pilot study is to test the feasibility and acceptability of a conscious connected breathing with breath retention intervention compared to a sham control condition.

METHODS

The rationale and procedures for testing a 5-day conscious connected breathing with breath retention intervention, compared to a deep breathing sham control intervention, in 24 adults (18-65 years) with cLBP is described. Both interventions will be delivered using standardized audio recordings and practiced over 5 days (two times in-person and three times at-home), and both are described as Breathing and Attention Training to reduce possible expectancy and placebo effects common in pain research. The primary outcomes for this study are feasibility and acceptability. Feasibility will be evaluated by determining rates of participant recruitment, adherence, retention, and study assessment completion, and acceptability will be evaluated by assessing participants' satisfaction and helpfulness of the intervention. We will also measure other clinical pain, psychological, behavioral, and physiological variables that are planned to be included in a follow-up randomized controlled trial.

DISCUSSION

This will be the first study to examine the effects of a conscious connected breathing with breath retention intervention for individuals with chronic pain. The successful completion of this smaller-scale pilot study will provide data regarding the feasibility and acceptability to conduct a subsequent trial testing the efficacy of this breathing self-management practice for adults with cLBP.

TRIAL REGISTRATION

Clinicaltrials.gov, identifier NCT04740710 . Registered on 5 February 2021.

Reducing decision-making deficits in patients with brain injury: effect of slow-paced breathing

Impairments in decision-making have been reported in brain-damaged (stroke/traumatic brain injury) patients with a wide range of lesion sites. Here, we propose that the performances of patients in complex sequential decision-making (DM) tasks can be explained by their negative affectivity, leading to deliberative processing associated with poor DM performances. We assumed that a slow-paced breathing (SPB) training, by reducing negative affectivity would improve performances in a complex DM task. For 24 days, 34 brain-damaged patients (16 males and 18 females; 12 had a hemorrhagic stroke, 17 with an ischemic stroke and 5 with a TBI), practiced either daily SPB or sham trainings for five min, three times a day. Before and after training, we assessed their vagal tone (electrocardiogram-ECG), affectivity (Positive and Negative Affect Schedule-PANAS) and certainty level (Dimensional Ratings Questionnaire-DRQ) and their performance on the Iowa Gambling Task. All participants showed initial weak performance, which improved only for patients in the SPB training condition. These results suggest that DM disorders in brain-damaged patients can be the consequence of their poor information processing strategy rather than an impairment in their DM abilities. Second, we showed that SPB could be efficient to normalize DM processes in brain injury patients.

A recent suicide attempt and the heartbeat: Electrophysiological findings from a trans-diagnostic cohort of patients and healthy controls

Suicidal behavior is influenced by a multitude of factors, making prediction and prevention of suicide attempts (SA) a challenge. A useful tool to uncover underlying pathophysiology or propose new therapy approaches are biomarkers, especially within the context of point-of-care tests. Heart rate variability (HRV) is a well-established biomarker of mental health, and measures the activity of the sympathetic and parasympathetic nervous system (PNS). Previous studies reported a correlation between lower PNS activity and suicidality. However, most studies involved participants from a healthy population, patients without history of suicide attempts, or patients with a single diagnosis. 52 in-patients with a recent suicide attempt (<6 months), and 43 controls without history of SA or psychiatric diagnoses confirmed study participation. The included patients age ranged between 18 and 65 years, 65% had psychiatric comorbidities. Patients with dementia, cognitive impairments, acute psychosis, chronic non suicidal self-harming behavior, or current electroconvulsive therapy were excluded. A 15-min resting state electrocardiography was recorded with two bipolar electrodes attached to the right and left insides of the wrists. The multiple regression analyses showed lower parasympathetic, and higher sympathetic activity in patients compared to controls. Partial correlation found a positive trend result between self-reported suicidality and the very low frequency band. ROC curve analysis revealed an acceptable to excellent clinical accuracy of HRV parameters. Therefore, HRV parameters could be reliable discriminative biomarkers between in-patients with a recent SA and healthy controls. One limitation is the lack of a control group consisting of in-patients without life-time suicidal ideation or attempts.

A preliminary systematic review and meta-analysis on the effects of heart rate variability biofeedback on heart rate variability and respiration of athletes

To date, there is no quantitative review examining the influence of heart rate variability biofeedback (HRV BFB) on the athlete population. Such an undertaking may provide valuable information on the autonomic and respiration responses of athletes when performing HRV BFB. Thus, purpose of this preliminary systematic review and meta-analysis on the effects of HRV BFB on HRV and respiration of athletes. Searches of Springerlink, SportDiscus, Web of Science, PROQUEST Academic Research Library, Google Scholar, and ScienceDirect were conducted for studies that met the following criteria: (1) experimental studies involving athletes that underwent randomized control trial; (2) availability of HRV BFB as a treatment compared with a control (CON)/placebo (PLA); (3) any pre and post HRV variable and/or breathing frequency as dependent variable/s; and, (4) peer-reviewed articles written in English. Four out of 660 studies involving 115 athletes (25 females and 90 males) ages 16-30 years old were assessed in this review. Preliminary findings suggest the promising ability of HRV BFB to improve respiratory mechanics in athlete population. More work is needed to determine the autonomic modulatory effect of HRV BFB in athletes.

Squeeze the beat: Enhancing cardiac vagal activity during resonance breathing via coherent pelvic floor recruitment

Resonance breathing (RB) has been shown to benefit health and performance within clinical and non-clinical populations. This is attributed to its baroreflex stimulating effect and the concomitant increase in cardiac vagal activity (CVA). Hence, developing methods that strengthen the CVA boosting effect of RB could improve its clinical effectiveness. Therefore, we assessed whether supplementing RB with coherent pelvic floor activation (PRB), which has been shown to entrain the baroreflex, yields stronger CVA than standard RB. N = 32 participants performed 5-min of RB and PRB, which requires to recruit the pelvic floor during the complete inspiratory phase and release it at the initiation of the expiration. CVA was indexed via heart rate variability using RMSSD and LF-HRV. PRB induced significantly larger RMSSD (d = 1.04) and LF-HRV (d = 0.75, ps &lt; .001) as compared to RB. Results indicate that PRB induced an additional boost in CVA relative to RB in healthy individuals. However, subsequent studies are warranted to evaluate whether these first findings can be replicated in individuals with compromised health, including a more comprehensive psychophysiological assessment to potentially elucidate the origin of the observed effects. Importantly, longitudinal studies need to address whether PRB translates to better treatment outcomes.

Effects of a randomised trial of 5-week heart rate variability biofeedback intervention on mind wandering and associated brain function

Previous research suggests that excessive negative self-related thought during mind wandering involves the default mode network (DMN) core subsystem and the orbitofrontal cortex (OFC). Heart rate variability (HRV) biofeedback, which involves slow paced breathing to increase HRV, is known to promote emotional well-being. However, it remains unclear whether it has positive effects on mind wandering and associated brain function. We conducted a study where young adults were randomly assigned to one of two 5-week interventions involving daily biofeedback that either increased heart rate oscillations via slow paced breathing (Osc+ condition) or had little effect on heart rate oscillations (active control or Osc- condition). The two intervention conditions did not differentially affect mind wandering and DMN core-OFC functional connectivity. However, the magnitude of participants' heart rate oscillations during daily biofeedback practice was associated with pre-to-post decreases in mind wandering and in DMN core-OFC functional connectivity. Furthermore, the reduction in the DMN core-OFC connectivity was associated with a decrease in mind wandering. Our results suggested that daily sessions involving high amplitude heart rate oscillations may help reduce negative mind wandering and associated brain function.

Comparing heart rate variability biofeedback and simple paced breathing to inform the design of guided breathing technologies

Introduction

A goal of inbodied interaction is to explore how tools can be designed to provide external interactions that support our internal processes. One process that often suffers from our external interactions with modern computing technology is our breathing. Because of the ergonomics and low-grade-but-frequent stress associated with computer work, many people adopt a short, shallow breathing pattern that is known to have a negative effect on other parts of our physiology. Breathing guides are tools that help people match their breathing patterns to an external (most often visual) cue to practice healthy breathing exercises.However, there are two leading protocols for how breathing cues are offered by breathing guides used in non-clinical settings: simple paced breathing (SPB) and Heart Rate Variability Biofeedback (HRV-b). Although these protocols have separately been demonstrated to be effective, they differ substantially in their complexity and design. Paced breathing is a simpler protocol where a user is asked to match their breathing pattern with a cue paced at a predetermined rate and is simple enough to be completed as a secondary task during other activities. HRV-b, on the other hand, provides adaptive, real-time guidance derived from heart rate variability, a physiological signal that can be sensed through a wearable device. Although the benefits of these two protocols have been well established in clinical contexts, designers of guided breathing technology have little information about whether one is better than the other for non-clinical use.

Methods

To address this important gap in knowledge, we conducted the first comparative study of these two leading protocols in the context of end-user applications. In our N=28 between-subject design, participants were trained in either SPB or HRV-b and then completed a 10-minute session following their training protocol. Breathing rates and heart rate variability scores were recorded and compared between groups.

Results and discussion

Our findings indicate that the exercises did not significantly differ in their immediate outcomes – both resulted in significantly slower breathing rates than their baseline and both provided similar relative increases in HRV. Therefore, there were no observed differences in the acute physiological effects when using either SPB or HRV-b. Our paper contributes new findings suggesting that simple paced breathing – a straightforward, intuitive, and easy-to-design breathing exercise – provides the same immediate benefits as HRV-b, but without its added design complexities.

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.

HEART rate variability biofeedback for long COVID symptoms (HEARTLOC): protocol for a feasibility study

INTRODUCTION

Long COVID (LC), also known as post-COVID-19 syndrome, refers to symptoms persisting 12 weeks after COVID-19 infection. It affects up to one in seven people contracting the illness and causes a wide range of symptoms, including fatigue, breathlessness, palpitations, dizziness, pain and brain fog. Many of these symptoms can be linked to dysautonomia or dysregulation of the autonomic nervous system after SARS-CoV2 infection. This study aims to test the feasibility and estimate the efficacy, of the heart rate variability biofeedback (HRV-B) technique via a standardised slow diaphragmatic breathing programme in individuals with LC.

METHODS AND ANALYSIS

30 adult LC patients with symptoms of palpitations or dizziness and an abnormal NASA Lean Test will be selected from a specialist Long COVID rehabilitation service. They will undergo a 4-week HRV-B intervention using a Polar chest strap device linked to the Elite HRV phone application while undertaking the breathing exercise technique for two 10 min periods everyday for at least 5 days a week. Quantitative data will be gathered during the study period using: HRV data from the chest strap and wrist-worn Fitbit, the modified COVID-19 Yorkshire Rehabilitation Scale, Composite Autonomic Symptom Score, WHO Disability Assessment Schedule and EQ-5D-5L health-related quality of life measures. Qualitative feedback on user experience and feasibility of using the technology in a home setting will also be gathered. Standard statistical tests for correlation and significant difference will be used to analyse the quantitate data.

ETHICS AND DISSEMINATION

The study has received ethical approval from Health Research Authority (HRA) Leicester South Research Ethics Committee (21/EM/0271). Dissemination plans include academic and lay publications.

TRIAL REGISTRATION NUMBER

NCT05228665.

Parasympathetic functioning and sleep problems in children with autism spectrum disorder

Respiratory sinus arrhythmia (RSA), an index of parasympathetic nervous system activity, has been linked with sleep quality among children with neurotypical development. The current study extended examination of these processes to children with autism spectrum disorder (ASD), a group at considerable risk for sleep problems. Participants included 54 children with ASD (aged 6-10 years, 43% Hispanic). RSA data were collected via a wired MindWare system during a 3-min baseline and a 3-min challenge task. Parents reported on their children's sleep problems and sleep duration using the Children's Sleep Habits Questionnaire, Abbreviated. Although no significant correlations emerged between RSA indices and parent-reported child sleep, baseline RSA and RSA reactivity interacted in the prediction of sleep problems. For children with higher RSA reactivity, higher baseline RSA was associated with fewer sleep problems, but for children with lower RSA reactivity, baseline RSA was not predictive. No main effects or interactions of RSA predicted sleep duration. Findings suggest resilience against sleep problems for children with ASD presenting with higher baseline RSA and higher RSA reactivity. Implications of these results center upon directly targeting psychophysiology (i.e., parasympathetic nervous system regulation) as a possible mechanism to improve sleep in children with ASD, and developing personalized interventions based on physiological markers of risk and resilience.

Breathing out dental fear: A feasibility crossover study on the effectiveness of diaphragmatic breathing in children sitting on the dentist's chair

BACKGROUND

Anxiety related to the dental context is a clinically significant challenge. In children, dental fear is often accompanied by disruptive and uncooperative behaviours that can render treatment difficult. Although techniques to reduce children's anxiety exist, many have not been formally evaluated.

DESIGN

Diaphragmatic breathing has been shown to reduce fear and anxiety, but few investigations have evaluated whether it can reduce dental anxiety in children. This crossover study tested the effectiveness and feasibility of diaphragmatic breathing in twenty children undergoing dental care.

RESULTS

Compared with the treatment as usual, such a simple technique had significant benefits on mood, self-reported pain and autonomic balance, thus reducing sympathetic activation.

CONCLUSION

Diaphragmatic breathing is a low-cost, easy-to-implement technique suitable for daily dental practice, and is a promising tool for reducing negative effect and physiological distress in children with dental anxiety that results in more cooperative behaviours and reduced visit time.

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.

A randomized clinical trial to stimulate the cholinergic anti-inflammatory pathway in patients with moderate COVID-19-pneumonia using a slow-paced breathing technique

Purpose

A characteristic problem occurring in COVID-19 is excessive elevations of pro-inflammatory cytokines (e.g. IL-6 and CRP) which are associated with worse clinical outcomes. Stimulation of the vagally-mediated cholinergic anti-inflammatory reflex by slow paced breathing with prolonged exhalation may present a clinically relevant way to reduce circulating IL-6.

Method

Single-center randomized controlled clinical trial with enrolment of 46 patients hospitalized with confirmed severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) infection and moderate COVID-19 pneumonia (primary diagnosis). Differences between intervention (4sec inhalation, 6sec exhalation for 20 minutes 3x daily) and control group in IL-6 calculated using multilevel mixed-effect linear regression models with random slope including the covariates relevant comorbidities, COVID-19 medication, and age. Both groups received standard care.

Results

Mean age was 57 years ± 13 years, N= 28 (60%) male, N=30 (65%) with relevant comorbidities. The model including group-by-time interaction revealed a significantly lower trajectory of IL-6 in the intervention group (effect size Cohens f² = 0.11, LR-test p=.040) in the intention-to-treat sample, confirmed by per-protocol analysis (f² = 0.15, LR-test p=.022). Exploratory analysis using the median split of practice time to predict IL-6 of the next morning indicated a dose-response relationship with beneficial effects of practice time above 45 minutes per day. Oxygen saturation remained unchanged during slow-paced breathing (95.1% ± 2.1% to 95.4% ± 1.6%).

Conclusion

Patients practicing slow-paced breathing had significantly lower IL-6 values than controls with a small to medium effect size and without relevant side effects. Further trials should evaluate clinical outcomes and an earlier start of the intervention. Slow-paced breathing could be an easy to implement, low-cost, safe and feasible adjuvant therapeutic approach to reduce circulating IL-6 in moderate COVID-19 pneumonia.

Clinical Trial Registration

https://www.drks.de, identifier DRKS00023971, Universal Trial Number (UTN) U1111-1263-8658.

A longitudinal investigation of the influence of psychological factors on nausea and vomiting in early pregnancy

The purpose of this study was to elucidate psychological factors that may influence nausea and vomiting during pregnancy (NVP) progression in early pregnancy based on longitudinal observations. Fifty-nine pregnant women completed the Rhodes Index of Nausea, Vomiting, and Retching (RINVR) and General Health Questionnaire-28 (GHQ-28), and recorded their resting heart rate with photoplethysmography for 5 min to determine heart rate variability (HRV) indexes at 7-9 weeks and 11-13 weeks of gestation with a 4-week interval. GHQ-28 scores (total and subclasses) and HRV indexes at 7-9 weeks were compared among groups classified according to the presence of severe NVP (RINVR ≥ 9 points) at the two measurement points. Among women without severe NVP at 7-9 weeks, women who developed severe NVP at 11-13 weeks had significantly higher levels of anxiety/insomnia in the GHQ-28 subclasses (p = 0.018). The cross-lagged relationship from anxiety/insomnia at 7-9 weeks to RINVR at 11-13 weeks was significant (β = 0.367, p &lt; 0.001). Among women with severe NVP at 7-9 weeks, women whose severe symptoms subsided at 11-13 weeks had significantly higher high-frequency (HF) power (p = 0.010), and women with relatively higher HF power demonstrated a significant reduction in RINVR (interaction effect, p = 0.035). During early pregnancy, women with strong anxiety/insomnia symptoms tend to have NVP symptoms that become more severe as the pregnancy progresses. The higher HF power in women whose severe NVP subsided within 4 weeks suggests a contribution of emotion regulation to early amelioration of NVP.

A simple version of resting-state heart rate variability interpretation for patients with affective disorders: A four-pattern perspective

Heart rate variability (HRV) is often considered as a biomarker reflecting well-being, but the clinical meaning of short-term resting-state HRV is not sufficiently defined. We assume that combining several common HRV indices as "HRV patterns" and using the patterns for screening purposes are meaningful approaches. Resting-state 5-min HRV data of 424 subjects were analyzed. Four of the most commonly used HRV indices were considered: standard deviation of normal-to-normal RR intervals, low-frequency power, high-frequency power and the ratio of low-frequency to high-frequency power. According to these indices, four HRV patterns were defined: normal pattern, low HRV pattern, relatively high sympathetic pattern, and relatively high vagal pattern. The associations between the demographics, lifestyles, personality traits, psychological states, and HRV patterns were explored: the low HRV pattern was positively associated with age, body mass index, and depression; the relatively high sympathetic pattern was positively associated with age and negatively associated with exercise habit; and the relatively high vagal pattern was negatively associated with having a steady job and novelty seeking. The pattern perspective may provide a convenient and evidence-based way to interpret resting-state HRV for patients with affective disorders.