Role of Paced Breathing for Treatment of Hypertension

The Rehabilitation Efficacy of the Novel Metronomic Breathing Technique for Gerontic Patients After Percutaneous Coronary Intervention for Acute Myocardial Infarction-A Pilot Study

Background

The respiratory rehabilitation technique is a crucial component of early cardiac recovery in geriatric patients with acute myocardial infarction (AMI). This study primarily investigated the effectiveness of a novel respiratory rehabilitation technique, metronomic breathing (MB), on geriatric patients after percutaneous coronary intervention for AMI and compliance with home-based rehabilitation compared to traditional respiratory rehabilitation.

Methods

From June 2022 to March 2023, 75 acute myocardial infarction (AMI) patients admitted to the Shanghai Tenth People's Hospital Cardiovascular Department were consecutively enrolled. Ultimately, 46 patients completed the follow-up in this study-26 in the MB group and 20 in the control group-who underwent the novel MB technique and conventional abdominal breathing training. The primary endpoint of the study was left ventricular function measured by noninvasive hemodynamics three months after discharge. The secondary endpoints were compliance and quality of life after three months of home rehabilitation.

Results

After the intervention, several cardiac functional parameters (SV, SVI, CO, CI, LCW, and LCWI), myocardial contractility parameters (VI), and systemic vascular resistance parameters (SVR and SVRI) were significantly greater in the MB group than in the preintervention group (P < 0.05). Furthermore, post-treatment, the MB group exhibited greater SV, SVI, CO, CI, and VI; lower SVR, SVRI, and SBP; and a lower readmission rate three months later than did the control group. The SF-36 scores after three months of MB intervention, PE, BP, GH, VT, SF, RE, and MH, were all significantly greater than those before treatment (P < 0.05). Moreover, the MB group displayed greater compliance with home-based cardiac rehabilitation (P < 0.05).

Conclusion

Compared to conventional respiratory rehabilitation training methods, short-term metronomic respiratory therapy is more effective for reducing systemic vascular resistance, enhancing left ventricular ejection function, enhancing quality of life, and increasing home-based rehabilitation compliance in geriatric patients following AMI with PCI.

Mindful breathing as an effective technique in the management of hypertension

Introduction: Hypertension is one of the most important, modifiable risk factors for cardiovascular disease. The popularity of wearable devices provides an opportunity to test whether device guided slow mindful breathing may serve as a non-pharmacological treatment in the management of hypertension. Methods: Fitbit Versa-3 and Sense devices were used for this study. In addition, participants were required to own an FDA or Health Canada approved blood pressure measuring device. Advertisements were shown to 655,910 Fitbit users, of which 7,365 individuals expressed interest and filled out the initial survey. A total of 1,918 participants entered their blood pressure readings on at least 1 day and were considered enrolled in the study. Participants were instructed to download a guided mindful breathing app on their smartwatch device, and to engage with the app once a day prior to sleep. Participants measured their systolic and diastolic blood pressure prior to starting each mindful breathing session, and again after completion. All measurements were self reported. Participants were located in the United States or Canada. Results: Values of systolic and diastolic blood pressure were reduced following mindful breathing. There was also a decrease in resting systolic and diastolic measurements when measured over several days. For participants with a systolic pressure ≥ 130 mmHg, there was a decrease of 9.7 mmHg following 15 min of mindful breathing at 6 breaths per minute. When measured over several days, the resting systolic pressure decreased by an average of 4.3 mmHg. Discussion: Mindful breathing for 15 min a day, at a rate of 6 breaths per minute is effective in lowering blood pressure, and has both an immediate, and a short term effect (over several days). This large scale study demonstrates that device guided mindful breathing with a consumer wearable for 15 min a day is effective in lowering blood pressure, and a helpful complement to the standard of care.

Effects of slow breathing training on hemodynamic changes, cardiac autonomic function and neuroendocrine response in people with high blood pressure: A randomized control trial

BACKGROUND

High blood pressure (BP) is a non-communicable disease that is a risk factor for cardiovascular disease and is the leading cause of mortality and morbidity worldwide. High BP can be managed by both pharmacological and non-pharmacological interventions. Non-pharmacological treatment, such as slow-breathing training (SBT), has been shown to reduce BP. However, there are few studies on the effect of SBT on both cardiac activation and oxidative stress in people with high BP.

OBJECTIVES

To explore the effect of SBT on cardiac autonomic function (i.e., heart rate variability: HRV) and neuroendocrine response (i.e., salivary cortisol).

METHODS

One hundred people (including 89 women) with high BP were randomly assigned to either a control (n = 50) or intervention group (n = 50). The intervention program was conducted for 30 min per day, for 5 days per week, for 4 weeks, with a total of 20 sessions of the SBT at the rate of 10 times per minute, whereas the control group was required to continue with their daily routine. HRV, BP, and salivary cortisol were measured before and after the intervention program. A two-way mixed ANOVA was performed for within-group and between-group comparisons over time.

RESULTS

Of the 100 participants, 71 individuals completed the study. The participants in the intervention group had a lower BP and salivary cortisol levels compared to those in the control group (p < .05). Further, those participants showed an increase in the standard deviation of normal R-R intervals after the 4-week intervention program (p < .05).

CONCLUSION

This study provided evidence demonstrating the effect of SBT on cardiac autonomic and stress reactivity, which has important implications for health promotion in people with high BP.

CLINICAL TRIAL REGISTRATION NUMBER

TCTR20180302008.

Putting back respiration into respiratory sinus arrhythmia or high-frequency heart rate variability: Implications for interpretation, respiratory rhythmicity, and health

Research on respiratory sinus arrhythmia, or high-frequency heart rate variability (its frequency-domain equivalent), has been popular in psychology and the behavioral sciences for some time. It is typically interpreted as an indicator of cardiac vagal activity. However, as research has shown for decades, the respiratory pattern can influence the amplitude of these noninvasive measures substantially, without necessarily reflecting changes in tonic cardiac vagal activity. Although changes in respiration are systematically associated with experiential and behavioral states, this potential confound in the interpretation of RSA, or HF-HRV, is rarely considered. Interpretations of within-individual changes in these parameters are therefore only conclusive if undertaken relative to the breathing pattern. The interpretation of absolute levels of these parameters between individuals is additionally burdened with the problem of residual inspiratory cardiac vagal activity in humans. Furthermore, multiple demographic, anthropometric, life-style, health, and medication variables can act as relevant third variables that might explain associations of RSA or HF-HRV with experiential and behavioral variables. Because vagal activity measured by these parameters only represents the portion of cardiac vagal outflow that is modulated by the respiratory rhythm, alternative interpretations beyond cardiac vagal activity should be considered. Accumulating research shows that activity of multiple populations of neurons in the brain and the periphery, and with that organ activity and function, are modulated rhythmically by respiratory activity. Thus, observable health benefits ascribed to the cardiac vagal system through RSA or HF-HRV may actually reflect beneficial effects of respiratory modulation. Respiratory rhythmicity may ultimately provide the mechanism that integrates central, autonomic, and visceral activities.

Closed-Loop Auditory Stimulation to Guide Respiration: Preliminary Study to Evaluate the Effect on Time Spent in Sleep Initiation during a Nap

Various stimulation systems to modulate sleep structure and function have been introduced. However, studies on the time spent in sleep initiation (TSSI) are limited. This study proposes a closed-loop auditory stimulation (CLAS) to gradually modulate respiratory rhythm linked to the autonomic nervous system (ANS) activity directly associated with sleep. CLAS is continuously updated to reflect the individual's current respiratory frequency and pattern. Six participants took naps on different days with and without CLAS. The average values of the TSSI are 14.00 ± 4.24 and 9.67 ± 5.31 min in the control and stimulation experiments (p < 0.03), respectively. Further, the values of respiratory instability and heart rate variability differ significantly between the control and stimulation experiments. Based on our findings, CLAS supports the individuals to gradually modulate their respiratory rhythms to have similar characteristics observed near sleep initiation, and the changed respiratory rhythms influence ANS activities, possibly influencing sleep initiation. Our approach aims to modulate the respiratory rhythm, which can be controlled intentionally. Therefore, this method can probably be used for sleep initiation and daytime applications.

Changes in the cardiac autonomic control system during rehabilitation in children after severe traumatic brain injury

BACKGROUND

One of the sequalae of severe traumatic brain injury (TBI) in children is impaired function of the cardiac autonomic control system (CACS) at rest. The CACS response to conventional autonomic tests is little known.

OBJECTIVE

To examine the CACS response to conventional autonomic tests in children after severe TBI during the rehabilitation period and to compare with typically developing (TD) children.

METHODS

This study combined a case-control and follow-up design. The severe TBI group (cases) consisted of 33 children aged 9-18 years, 14-142 days after severe TBI who were followed for 8 weeks during rehabilitation. The control group consisted of 19 TD children matched for age and sex. Heart rate (HR) and heart rate variability (HRV) were evaluated with the Polar RS800CX device at rest (sitting), during a handgrip test and during a paced breathing test.

RESULTS

At the first assessment, we found lower HRV values at rest and a lower HRV response during the paced breathing and handgrip tests in the TBI group than the TD group (p<0.01). After 8 weeks, HRV values did not change at rest in the TBI group, but the response to the autonomic tests improved significantly, with increased HRV values in response to the paced breathing test (p<0.01) and the handgrip test (p = 0.01).

CONCLUSIONS

After severe TBI, children exhibited an impaired CACS response to autonomic tests, with parasympathetic suppression and sympathetic arousal. After 8 weeks of rehabilitation, CACS function recovered partially and the response to the autonomic tests improved with no change in CACS function at rest.

Device and nondevice‐guided slow breathing to reduce blood pressure in hypertensive patients: A systematic review and meta‐analysis

Backgroud and Aims

Hypertension (HTN) is a multifactorial chronic disease. Considering the high prevalence rates of this disease, treatment of HTN is necessary, not only to reduce blood pressure (BP) levels but also to prevent the development of cardiovascular, cerebrovascular, and kidney diseases. This treatment can be through medication, which will be determined according to the BP values, obtained either in medical consultations or at home; presence of cardiovascular risk factors, and the presence of target organ damage identified during anamnesis. The aim of this systematic review and meta‐analysis is to summarize the effects of device‐guided slow breathing (DGSB) and nondevice‐guided slow breathing (NDGSB) on BP levels of patients with HTN.

Methods

This study is a systematic review and meta‐analysis of randomized clinical trials, pertaining to hypertensive patients, with or without comorbidity, over 18 years old, of both sexes, and with or without hypertensive medication. The selected studies showed comparisons between groups that performed DGSB and/or NDGSB with control conditions. The primary outcome was the value of systolic blood pressure (SBP) and diastolic blood pressure (DBP) after the interventions.

Results

Twenty‐two studies involving 17,214 participants were included in the quantitative analysis. Considerable heterogeneity was revealed between studies. Using random effect model, it was found that DGSB did not significantly reduce SBP and DBP compared to usual care, both in terms BP values and in relation to their variations (SBP, mean difference [MD]: −2.13 mmHg, (95% confidence interval [CI]: −12.71 to 8.44), 288 individuals; I² = 93%, high heterogenity: DBP, MD: −0.90, 95% CI: −3.97 to 2.11, 288 individuals; I² = 63%, substantial heterogenity. SBP variations MD: −2.42, 95% CI: −7.24 to 2.40, 443 individuals; I² = 85% high heterogenity/DBP variations MD: −1.67, 95% CI: −4.57 to 1.24, 443 individuals; I² = 80%, high heterogenity).

Conclusion

Based on these results it appears that DGSB did not reduce BP in hypertensive patients and NDGSB is a new path for the future.

Device- and Nondevice-Guided Slow Breathing to Reduce Blood Pressure in Patients with Hypertension: Protocol for a Systematic Review and Meta-analysis

Background

Physiotherapy can include both device-guided slow breathing (DGSB) and nondevice-guided slow breathing (NDGSB) in the treatment of systemic arterial hypertension.

Objective

The aim of this study is to summarize the effects of DGSB on blood pressure levels of patients with hypertension based on the published literature to date.

Methods

A systematic search of all published randomized controlled trials (RCTs) on the effects of device-guided and nondevice-guided slow breathing in patients with hypertension, without language restriction, was carried out up to a publication date of January 2020 in nine databases: PubMed/MEDLINE, Latin American and Caribbean Health Sciences Literature (LILACS), EMBASE, CENTRAL (Cochrane Central Register of Controlled Trials), Physiotherapy Evidence Database (PEDro), CINAHL (Cumulative Index to Nursing and Allied Health Literature), Scopus, Web of Science, and Livivo. Clinical trial records databases (ClinicalTrials.gov), and bases for the open gray literature, including Gray Literature Report and ProQuest Central (Citation, Abstract or Indexing, and Dissertations and Theses), were also searched for potentially eligible RCTs. The quality assessment of the included studies will be performed using the Cochrane Risk of Bias Tool for Randomized Trials. The overall quality of the evidence for each outcome will be assessed using the GRADE (Grading of Recommendations, Development and Evaluation) system.

Results

As of December 2021, the review was completed and all data from continuous variables referring to blood pressure values (mmHg) were synthesized.

Conclusions

This systematic review will provide a summary of the current evidence on the effects of both DGSB and NDGSB on blood pressure levels. This information can contribute to decision-making by health professionals related to the use of these interventions in patients with hypertension.

Trial Registration

PROSPERO (Prospective International Register of Systematic Reviews) CRD42020147554; https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=147554

International Registered Report Identifier (IRRID)

RR1-10.2196/33579

Investigating components of pranayama for effects on heart rate variability

OBJECTIVE

Traditional Indian breath control practices of Pranayama have been shown to increase indices of heart rate variability (HRV) that are generally held to reflect parasympathetic nervous system (PNS) tone. To our knowledge, individual components of pranayama have not been separately evaluated for impact on HRV. The objective of this study was to isolate five components of a pranayama practice and evaluate their impact on HRV.

METHODS

In a crossover clinical trial, 46 healthy adults were allocated to complete five activities in random order, over five separate visits: 1) sitting quietly; 2) self-paced deep breathing; 3) externally-paced deep breathing; 4) self-paced Sheetali/Sheetkari pranayama; and 5) externally paced Sheetali/Sheetkari pranayama RESULTS: Our final sample included 25 participants. There was a significant increase in a time-domain index of HRV, the root mean square successive differences between RR intervals (RMSSD), during the five interventions. The change in logRMSSD ranged from 0.2 to 0.5 (p < .01 in all conditions by paired t-test). Greater increases were evident during externally-paced breathing than during self-paced breathing (mean pre-during logRMSSD change of 0.50 vs. 0.36, p = .02) or sitting quietly (mean, 0.17 ms; p = .005 and 0.02 when comparing Activities 3 and 5 to Activity 1 by random intercept model with Tukey correction for multiple comparisons). Lastly, pre-during increase in RMSSD was greater for Sheetali/Sheetkari vs. deep breathing, when controlling for respiration rate, though not significantly different (p = .07 in random intercept model) CONCLUSIONS: RMSSD increased with paced breathing, deep breathing, and Sheetali/Sheetkari pranayama, reinforcing evidence of a physiologic mechanism of pranayama.

TRIAL REGISTRATION

NCT03280589 https://www.clinicaltrials.gov/ct2/show/NCT03280589?term=sheetali&draw=2&rank=1.

Transcutaneous Auricular Vagus Nerve Stimulation Combined With Slow Breathing: Speculations on Potential Applications and Technical Considerations

OBJECTIVES

Transcutaneous auricular vagus nerve stimulation (taVNS) is a relatively novel noninvasive neurostimulation method that is believed to mimic the effects of invasive cervical VNS. It has recently been suggested that the effectiveness of taVNS can be enhanced by combining it with controlled slow breathing. Slow breathing modulates the activity of the vagus nerve and is used in behavioral medicine to decrease psychophysiological arousal. Based on studies that examine the effects of taVNS and slow breathing separately, this article speculates on some of the conditions in which this combination treatment may prove effective. Furthermore, based on findings from studies on the optimization of taVNS and slow breathing, this article provides guidance on how to combine taVNS with slow breathing.

MATERIALS AND METHODS

A nonsystematic review.

RESULTS

Both taVNS and slow breathing are considered promising add-on therapeutic approaches for anxiety and depressive disorders, chronic pain, cardiovascular diseases, and insomnia. Therefore, taVNS combined with slow breathing may produce additive or even synergistic beneficial effects in these conditions. Studies on respiratory-gated taVNS during spontaneous breathing suggest that taVNS should be delivered during expiration. Therefore, this article proposes to use taVNS as a breathing pacer to indicate when and for how long to exhale during slow breathing exercises.

CONCLUSIONS

Combining taVNS with slow breathing seems to be a promising hybrid neurostimulation and behavioral intervention.

Effects of slow and deep breathing on reducing obstetric intervention in women with pregnancy-induced hypertension: a feasibility study protocol

Objective: To evaluate whether a slow and deep breathing (SDB) intervention is acceptable to pregnant women. Methods: The trial aims to recruit 67 pregnant women who have developed pregnancy-induced hypertension (clinicaltrials.gov: NCT04059822). SDB will be undertaken daily for 10 min using a video aid and women will self-monitor blood pressure (BP) daily. At 36-weeks gestation women will complete an online questionnaire. Adherence, recruitment rates, and acceptance of the intervention will be evaluated. Conclusion: The findings from this trial will evaluate if women accept SDB as a treatment method. Initial analysis will evaluate if BP and/or obstetric interventions reduce following SDB intervention.

Does Gender Influence the Relationship Between High Blood Pressure and Dementia? Highlighting Areas for Further Investigation

BACKGROUND

Gender differences have been noted in studies linking blood pressure to all-cause dementia, and the two most common forms of dementia: Alzheimer's disease (AD) and vascular dementia (VaD). However, how gender modifies the relationship between blood pressure and dementia remains unclear.

OBJECTIVE

To review evidence for a gender modifying effect on the link between blood pressure and all-cause dementia.

METHODS

A systematic review was conducted according to PRISMA guidelines. Sixteen out of 256 reviewed articles met inclusion criteria.

RESULTS

For women, higher midlife systolic blood pressure (SBP) and hypertension were both associated with greater risk of all-cause dementia, AD, and VaD, in six out of seven studies. Two of these studies reported higher midlife SBP/hypertension were associated with greater risk for all-cause dementia in women, but not men. One study reported higher midlife SBP associated with greater AD risk in women, but not men. However, another study reported that midlife hypertension associated with AD risk in men, but not women. No clear gender differences were reported in the relationship between late-life high blood pressure/hypertension with all-cause dementia or AD.

CONCLUSION

Studies rarely, and inconsistently, analyzed or reported gender effects. Therefore, interpretation of available evidence regarding the role of gender in blood pressure associated dementia was difficult. Several studies indicated higher midlife SBP was associated with greater risk of all-cause dementia for women, compared to men. Future studies should evaluate women-specific aging processes that occur in midlife when considering the association between blood pressure and dementia risk.

Quantifying the Delays Between Multi-Site Photoplethysmography Pulse and Electrocardiogram R-R Interval Changes Under Slow-Paced Breathing

Objective: Objective assessment of autonomic function is important, including the investigation of slow-paced breathing to induce associated periodic changes in the cardiovascular system – such as blood pressure and heart rate. However, pulse changes across a range of peripheral body sites have seldom been explored with this challenge. The primary aim of this pilot study was to utilize multi-site photoplethysmography (MPPG) technology to quantify the phase delays, i.e., correlation lags, between changes in heart rate and changes in key pulse features with slow-paced breathing (0.1 Hz).

Methods: Waveforms were collected simultaneously from the right and left ear lobes, thumbs, and great toes of 18 healthy adult subjects. Cross correlation lags between reference beat-to-beat changes in electrocardiogram (ECG) R-R wave interval and changes in pulse arrival time (foot of pulse; PATf) and also for pulse amplitude (foot-to-peak; AMP) were determined.

Results: Relative to R-R changes, the median ear, thumb, and toe PATf correlation lags were 3.4, 2.9, and 2.1 beats, respectively; contrasting to AMP with 5.7, 6.0, and 6.9 beats, respectively. These PATf correlation lags in beats were significantly lower than for the AMP measure. Segmental differences between sites and timing measure variability have also been quantified.

Conclusion: This pilot study has indicated bilateral similarity plus segmental differences for relative delays in PPG pulse timing and amplitude measures relative to R-R interval changes with paced breathing. These correlation and variability data are now available for comparison with cardiovascular patient groups to support development of autonomic function assessment techniques.

Possible Breathing Influences on the Control of Arterial Pressure After Sino-aortic Denervation in Rats

PURPOSE OF REVIEW

Surgical removal of the baroreceptor afferents [sino-aortic denervation (SAD)] leads to a lack of inhibitory feedback to sympathetic outflow, which in turn is expected to result in a large increase in mean arterial pressure (MAP). However, few days after surgery, the sympathetic nerve activity (SNA) and MAP of SAD rats return to a range similar to that observed in control rats. In this review, we present experimental evidence suggesting that breathing contributes to control of SNA and MAP following SAD.The purpose of this review was to discuss studies exploring SNA and MAP regulation in SAD rats, highlighting the possible role of breathing in the neural mechanisms of this modulation of SNA.

RECENT FINDINGS

Recent studies show that baroreceptor afferent stimulation or removal (SAD) results in changes in the respiratory pattern. Changes in the neural respiratory network and in the respiratory pattern must be considered among mechanisms involved in the modulation of the MAP after SAD.