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.

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.

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 effects of alpha asymmetry and high-beta down-training neurofeedback for patients with the major depressive disorder and anxiety symptoms.

BACKGROUND: Alpha-asymmetry neurofeedback (ALAY) was applied to patients with major depressive disorder (MDD) based on the theory of frontal alpha asymmetry. Neurophysiological studies have found a higher high-beta activity of electroencephalography (EEG) at the posterior cortex among patients with comorbid MDD and anxiety symptoms. The present study examined the effects of ALAY and high-beta down-training (Beta) neurofeedback in symptoms of depression and anxiety and EEG parameters. METHOD: Eighty-seven patients with comorbid MDD and anxiety symptoms were allocated to the ALAY, Beta, or control groups. Both neurofeedback groups received ten-session neurofeedback. All participants completed the Beck Depression Inventory II (BDI-II), Beck Anxiety Inventory (BAI), and five minutes resting EEG recording at pre-test and post-test. EEG raw signals were transformed into an A1 score [log (F4 alpha) - log (F3 alpha)], P3 and P4 high-beta power. RESULTS: BDI-II and BAI scores decreased at post-test in both ALAY and Beta groups, but no significant difference between the two groups. No significant interaction effect in A1 score at pre-test and post-test between the ALAY, Beta, and control groups. The P3 high-beta was significantly decreased in the Beta group, an increase in the control group, and no change in the ALAY group at post-test compared to the pre-test. CONCLUSIONS: Both neurofeedback groups decreased symptoms of depression and anxiety. The Beta group was more effective in decreasing high-beta power at the parietal cortex compared to other groups. This non-invasive psychological intervention can be used in the future for patients with comorbid MDD and anxiety symptoms.

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.

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

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