Long-term effects of device-guided slow breathing in stable heart failure patients with reduced ejection fraction

Comparison of diaphragmatic breathing exercises and incentive spirometry on the functional status of heart failure patients: a randomized controlled trial

BACKGROUND

Respiratory muscle weakness in heart failure (HF) can deteriorate its symptoms such as fatigue, dyspnea, and impaired functional status. Pulmonary rehabilitation can strengthen these muscles. This study aimed to determine the impact of breathing exercises on fatigue severity, dyspnea, and functional classification in HF patients.

METHODS

A three-arm single-blind randomized controlled trial was conducted on 90 hospitalized HF patients in three 30-participant groups including diaphragmatic breathing group (DG), incentive spirometry group (SG), and control group (CG). The interventions were performed thrice daily for 10 days in DG and SG. The Fatigue Severity Scale (FSS), Borg dyspnea scale, and New York Heart Association (NYHA) functional classification were used before and after the intervention. Data were analyzed using SPSS-20 software.

RESULTS

After the intervention, the patients' frequency with severe fatigue decreased by 30% in both DG and SG (p < 0.001); the mean dyspnea score in DG and SG respectively reduced by 0.7 and 0.9 units at rest (p < 0.001) and reduced by 2.93 and 2.73 units during activity (p < 0.001); the total patients' frequency in functional class III and IV was significantly decreased by 30% in DG and 33.3% in SG (p < 0.001). The intervention groups were not significantly different regarding fatigue severity, dyspnea, and functional classification. While in CG these outcomes had no significant reduction after the intervention.

CONCLUSION

In this study breathing exercises could reduce fatigue and dyspnea, and improve NYHA functional classification of HF patients which can be included in nursing care plans for respiratory rehabilitation in HF.

TRIAL REGISTRATION

This study was prospectively registered by the Iranian Registry of Clinical Trials ( https://irct.behdasht.gov.ir/ ) on 14/04/2024 with registration ID: IRCT20240306061197N.

Improved exercise ventilatory efficiency with nasal compared to oral breathing in cardiac patients

Objectives: To assess whether nasal breathing improves exercise ventilatory efficiency in patients with heart failure (HF) or chronic coronary syndromes (CCS). Background: Exercise inefficient ventilation predicts disease progression and mortality in patients with cardiovascular diseases. In healthy people, improved ventilatory efficiency with nasal compared to oral breathing was found. Methods: Four study groups were recruited: Patients with HF, patients with CCS, old (age≥45 years) and young (age 20-40 years) healthy control subjects. After a 3-min warm-up, measurements of 5 min with once nasal and once oral breathing were performed in randomized order at 50% peak power on cycle ergometer. Ventilation and gas exchange parameters measured with spiroergometry were analysed by Wilcoxon paired-sample tests and linear mixed models adjusted for sex, height, weight and test order. Results: Groups comprised 15 HF, CCS, and young control and 12 old control. Ventilation/carbon dioxide production (V ˙ E/V ˙ CO2), ventilation (V ˙ E), breathing frequency (fR), and end-tidal oxygen partial pressure (PETO2) were significantly lower and tidal volume and end-tidal carbon dioxide partial pressure (PETCO2) significantly higher during nasal compared to oral breathing in all groups, with large effect sizes for most parameters. For patients with HF, medianV ˙ E/V ˙ CO2 was 35% lower, fR 26% lower, and PETCO2 10% higher with nasal compared to oral breathing, respectively. Exercise oscillatory ventilation (EOV) was present in 6 patients and markedly reduced with nasal breathing. Conclusion: Nasal breathing during submaximal exercise significantly improved ventilatory efficiency and abnormal breathing patterns (rapid shallow breathing and EOV) in 80% of our patients with HF and CCS.

Effect of breathing exercises on blood pressure and heart rate: A systematic review and meta-analysis

Background

Breathing exercises have been reported to have positive physiological effects on the body. The incidence of hypertension has become a major risk factor for cardiac complications leading to higher morbidity and mortality. Our aim was to conduct a systematic review and meta-analysis to study the effect of breathing exercises on blood pressure (BP) and heart rate (HR).

Methods

A systematic review and meta-analysis analyzing randomized clinical trials (RCTs) about the effect of breathing exercises on blood pressure was conducted (PROSPERO Registration ID: CRD42022316413). PubMed, ScienceDirect, WebofScience, and Cochrane Library databases were screened for RCTs from January 2017 to September 2022. The main search terms included "breathing exercise", "Pranayam", "Bhramari", "alternate nostril breathing", "deep breathing", "slow breathing", "hypertension", and "high blood pressure". The primary outcome was the value of the systolic blood pressure and diastolic blood pressure after the intervention. The effect on heart rate was also analyzed as a secondary outcome.

Results

A total of 15 studies were included in the meta-analysis. Breathing exercises have a modest but significant effect on decreasing systolic blood pressure (-7.06 [-10.20, -3.92], P = <0.01) and diastolic blood pressure (-3.43 [-4.89, -1.97], P = <0.01) mm Hg. Additionally, breathing exercises were also observed to cause a significant decrease in the heart rate (-2.41 [-4.53, -0.30], P = 0.03) beats/minute.

Conclusion

In a comprehensive systematic review and meta-analysis of breathing exercises and its effect on BP and HR, there is a moderate but significant positive effect. The studies are not deprived of bias.

Breathing pattern and pulmonary gas exchange in elderly patients with and without left ventricular dysfunction-modification with exercise-based cardiac rehabilitation and prognostic value

Background

Inefficient ventilation is an established prognostic marker in patients with heart failure. It is not known whether inefficient ventilation is also linked to poor prognosis in patients with left ventricular dysfunction (LVD) but without overt heart failure.

Objectives

To investigate whether inefficient ventilation in elderly patients with LVD is more common than in patients without LVD, whether it improves with exercise-based cardiac rehabilitation (exCR), and whether it is associated with major adverse cardiovascular events (MACE).

Methods

In this large multicentre observational longitudinal study, patients aged ≥65 years with acute or chronic coronary syndromes (ACS, CCS) without cardiac surgery who participated in a study on the effectiveness of exCR in seven European countries were included. Cardiopulmonary exercise testing (CPET) was performed before, at the termination of exCR, and at 12 months follow-up. Ventilation (VE), breathing frequency (BF), tidal volume (VT), and end-expiratory carbon dioxide pressure (PETCO2) were measured at rest, at the first ventilatory threshold, and at peak exercise. Ventilatory parameters were compared between patients with and without LVD (based on cardio-echography) and related to MACE at 12 month follow-up.

Results

In 818 patients, age was 72.5 ± 5.4 years, 21.9% were women, 79.8% had ACS, and 151 (18%) had LVD. Compared to noLVD, in LVD resting VE was increased by 8%, resting BF by 6%, peak VE, peak VT, and peak PETCO2 reduced by 6%, 8%, and 5%, respectively, and VE/VCO2 slope increased by 11%. From before to after exCR, resting VE decreased and peak PETCO2 increased significantly more in patients with compared to without LVD. In LVD, higher resting BF, higher nadir VE/VCO2, and lower peak PETCO2 at baseline were associated with MACE.

Conclusions

Similarly to patients with HF, in elderly patients with ischemic LVD, inefficient resting and exercise ventilation was associated with worse outcomes, and ExCR alleviated abnormal breathing patterns and gas exchange parameters.

Existing Meditation and Breathing Devices for Stress Reduction and Their Incorporated Stimuli: A Systematic Literature Review and Competition Analysis

To identify, evaluate, and summarize existing meditation and breathing devices for stress reduction and their characteristics (stimuli), we searched PubMed and EMBASE for studies published from January 1, 1980, to December 30, 2021. Full-text articles that presented devices that support meditation and breathing guidance for stress reduction were included. We excluded articles covering study protocols. In addition, a competitor analysis was conducted to identify and evaluate the devices, their name, manufacturer, target group, function, and incorporated stimuli were contracted. The scientific literature identified 367 studies, of which 20 (describing 18 devices and 32 stimuli) were included. The competition analysis identified 66 devices incorporating 126 stimuli. After exclusion of duplicates, this resulted in 46 different types of devices incorporating 24 different types of stimuli. They were organized into 7 device categories (attachable to the head, huggable devices, handheld devices, eye masks, mouth-controlled devices, toys, and wearables) and 14 stimuli categories (perceptible vibrations, imperceptible vibrations, movement, temperature, pressure, texture, light or darkness, abstract visuals, concrete visuals, music, calming sounds, tones, voice guidance, and aromas). This review provides an overview of the different meditation and breathing devices for stress reduction. The current overview will inform a subsequent preference and effectiveness study of breathing devices that aims to gain more knowledge on the topic to increase device uptake and developmental success.

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.

Exploring mechanisms of blood pressure regulation in response to device-guided and non-device-guided slow breathing: A mini review

BACKGROUND

Hypertension is a widespread disease that, if persistent, increases the risks of coronary heart disease mortality and morbidity. Slow breathing is a recommended blood pressure-lowering strategy though the mechanisms mediating its effects are unknown.

OBJECTIVE

This review aims to evaluate autonomic and vascular function as potential mediators driving BP adaptive responses with slow breathing.

METHODS

We searched EBSCO host, Web of Science, Cochrane Central Register of Controlled Trials, and PubMed using key words for optimized search results.

RESULTS

Nineteen studies were included in this review (11 device-guided; 8 non-device-guided breathing). Though some studies showed increased vagally mediated components of heart rate variability during slow breathing, results from acute and long-term studies were incongruent. Increases in baroreflex sensitivity (BRS) following a single device-guided slow breathing bout were noted in normotensive and hypertensive adults. Long-term (4 weeks to 3 months) effects of slow breathing on BRS were absent. Device-guided breathing resulted in immediate reductions in muscle sympathetic nerve activity (MSNA) in normo- and hyper-tensive adults though results from long-term studies yielded inconsistent findings. Non-device-guided slow breathing posed acute and chronic effects on vascular function with reductions in arterial stiffness in adults with type I diabetes and increases in microvascular endothelial function in adults with irritable bowel syndrome. Non-device guided breathing also reduced pro-inflammatory cytokines in healthy and hypertensive adults in acute and chronic studies. No adverse effects or non-adherence to treatment were noted in these trials.

CONCLUSION

Device-guided slow breathing is a feasible and effective modality in improving BRS, HRV, and arterial stiffness though its long-term effects are obscure. Though less evidence exists supporting the efficacy of non-device-guided slow breathing, acute and chronic studies demonstrate improvements in vascular function and inflammatory cytokines. More studies are needed to further explore the long-term effects of slow breathing in general and non-device-guided breathing in particular.

Parasympathetic Versus Sympathetic Changes in Heart Rate Variability After a Multimodal Integrative Medicine Intervention for Frontline COVID-19 Personnel

OBJECTIVE

Frontline healthcare providers (HCPs) working in COVID-19 hospital departments need to deal with considerable physical and emotional stress on a daily basis. We conducted a pilot study to examine changes in heart rate variability (HRV) in frontline COVID-19 personnel after an integrative medicine (IM) intervention.

METHODS

HCPs working in isolated COVID-19 inpatient departments underwent a single 30-minute individually tailored IM sessions combining various IM modalities (acupuncture, mind-body, and/or manual-movement modalities, including anthroposophic medicine). HRV parameters were compared during the first IM session at 3-minute intervals, at the beginning of treatments, and after 20 minutes. Root mean square of successive RR interval differences (RMSSD) was measured, as were domains of time (standard deviation of NN intervals, percentage of successive RR intervals that differ by more than 50 milliseconds) and frequency (low frequency/high frequency [LF/HF] ratio). Preintervention and postintervention concerns were assessed using the Measure Yourself Concerns and Well-being questionnaire, with posttreatment free-text narratives analyzed for clusters of emotional- and spiritual-related keywords (ESKs).

RESULTS

A total of 114 HCPs underwent an IM treatment session, and their HRV values were measured, of which 75 (65.8%) expressed ESKs. The RMSSD increased only in the ESK-expressing group ( p < .001). LF/HF ratios decreased in both groups, with HF power increasing in the ESK-expressing ( p = .043) and LF power decreasing in the non-ESK-expressing groups ( p = .004).

CONCLUSIONS

Increased parasympathetic activity was observed in all HCPs after the IM intervention, particularly among those expressing ESKs. LF/HF parameters suggest different relaxation-associated mechanisms, with increased HF (regulated predominantly by parasympathetic tone) in the ESK-expressing and decreased LF (regulated partially by sympathetic tone) in the nonexpressing group. Additional research needs to explore the relationship between subjective effects of the IM intervention and physiological mechanisms of relaxation in HCPs working in stressful environments.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT05104827.

Reducing Test Anxiety by Device-Guided Breathing: A Pilot Study

Test anxiety remains a challenge for students and has considerable physiological and psychological impacts. The routine practice of slow, Device-Guided Breathing (DGB) is a major component of behavioral treatments for anxiety conditions. This paper addresses the effectiveness of using DGB as a self-treatment clinical tool for test anxiety reduction. This pilot study sample included 21 healthy men and women, all college students, between the ages of 20 and 30. Participants were randomly assigned to two groups: DGB practice (n = 10) and wait-list control (n = 11). At the beginning and the end of 3-weeks DGB training, participants underwent a stress test, followed by measures of blood pressure and reported anxiety. Anxiety reduction in the DGB group as compared to controls was not statistically significant, but showed a large effect size. Accordingly, the clinical outcomes suggested that daily practice of DGB may lead to reduced anxiety. We assume that such reduction may lead to improved test performance. Our results suggest an alternative treatment for test anxiety that may also be relevant for general anxiety, which is likely to increase due to the ongoing COVID-19 pandemic.

Coupling between Blood Pressure and Subarachnoid Space Width Oscillations during Slow Breathing

The precise mechanisms connecting the cardiovascular system and the cerebrospinal fluid (CSF) are not well understood in detail. This paper investigates the couplings between the cardiac and respiratory components, as extracted from blood pressure (BP) signals and oscillations of the subarachnoid space width (SAS), collected during slow ventilation and ventilation against inspiration resistance. The experiment was performed on a group of 20 healthy volunteers (12 females and 8 males; BMI =22.1±3.2 kg/m2; age 25.3±7.9 years). We analysed the recorded signals with a wavelet transform. For the first time, a method based on dynamical Bayesian inference was used to detect the effective phase connectivity and the underlying coupling functions between the SAS and BP signals. There are several new findings. Slow breathing with or without resistance increases the strength of the coupling between the respiratory and cardiac components of both measured signals. We also observed increases in the strength of the coupling between the respiratory component of the BP and the cardiac component of the SAS and vice versa. Slow breathing synchronises the SAS oscillations, between the brain hemispheres. It also diminishes the similarity of the coupling between all analysed pairs of oscillators, while inspiratory resistance partially reverses this phenomenon. BP–SAS and SAS–BP interactions may reflect changes in the overall biomechanical characteristics of the brain.

Eight weeks of device-guided slow breathing decreases sympathetic nervous reactivity to stress in posttraumatic stress disorder

Posttraumatic stress disorder (PTSD) is characterized by increased risk for developing hypertension and cardiovascular disease. We recently showed that device-guided slow breathing (DGB) acutely lowers blood pressure (BP) and muscle sympathetic activity (MSNA) and improves baroreflex sensitivity (BRS) in PTSD. The aim of this study was to assess the long-term benefits of DGB on autonomic function at rest and during stress. We hypothesized that long-term DGB improves arterial BRS and lowers BP and MSNA in PTSD. Twenty-five veterans with PTSD were studied and randomized to either 8 wk of daily DGB (n = 12) or 8 wk of sham device (Sham; n = 13). BP, heart rate (HR), and MSNA were measured at rest and during mental math. Arterial BRS was assessed using the modified Oxford technique. Resting MSNA, BP, and heart rate (HR) remained comparable before and after 8 wk in both groups (DGB and Sham). Likewise, the change in sympathetic and cardiovagal BRS was not different between the groups. Interestingly, DGB significantly decreased MSNA reactivity to mental math when expressed as burst frequency (P = 0.012) or burst incidence (P = 0.008) compared with Sham, suggesting a sustained effect of DGB on sympathetic reactivity to stress in PTSD. Contrary to our hypothesis, long-term DGB did not lower systolic BP, diastolic BP, or HR responses to stress compared with Sham. Likewise, pulse pressure reactivity after 8 wk (P = 0.121) was also comparable. In summary, these data suggest that long-term use of DGB may lead to a sustained dampening of sympathetic reactivity to mental stress in PTSD.

Heart rate and blood pressure monitoring in heart failure

It has been long known that incessant tachycardia and severe hypertension can cause heart failure (HF). In recent years, it has also been recognized that more modest elevations in either heart rate (HR) or blood pressure (BP), if sustained, can be a risk factor both for the development of HF and for mortality in patients with established HF. Heart rate and BP are thus both modifiable risk factors in the setting of HF. What is less clear is the question whether routine systematic monitoring of these simple physiological parameters to a target value can offer clinical benefits. Measuring these parameters clinically during patient review is recommended in HF management in most HF guidelines, both in the acute and chronic phases of the disease. More sophisticated systems now allow long-term automatic or remote monitoring of HR and BP and whether this more detailed patient information can improve clinical outcomes will require prospective RCTs to evaluate. In addition, analysis of patterns of both HR and BP variability can give insights into autonomic function, which is also frequently abnormal in HF. This window into autonomic dysfunction in our HF patients can also provide further independent prognostic information and may in itself be target for future interventional therapies. This article, developed during a consensus meeting of the Heart Failure Association of the ESC concerning the role of physiological monitoring in the complex multi-morbid HF patient, highlights the importance of repeated assessment of HR and BP in HF, and reviews gaps in our knowledge and potential future directions.

Impact of slow breathing on the blood pressure and subarachnoid space width oscillations in humans

The aim of the study was to assess cardiac and respiratory blood pressure (BP) and subarachnoid space (SAS) width oscillations during the resting state for slow and fast breathing and breathing against inspiratory resistance. Experiments were performed on a group of 20 healthy volunteers (8 males and 12 females; age 25.3 ± 7.9 years; BMI = 22.1 ± 3.2 kg/m2). BP and heart rate (HR) were measured using continuous finger-pulse photoplethysmography. SAS signals were recorded using an SAS monitor. Oxyhaemoglobin saturation (SaO2) and end-tidal CO2 (EtCO2) were measured using a medical monitoring system. Procedure 1 consisted of breathing spontaneously and at controlled rates of 6 breaths/minute and 6 breaths/minute with inspiratory resistance for 10 minutes. Procedure 2 consisted of breathing spontaneously and at controlled rates of 6, 12 and 18 breaths/minute for 5 minutes. Wavelet analysis with the Morlet mother wavelet was applied for delineation of BP and SAS signals cardiac and respiratory components. Slow breathing diminishes amplitude of cardiac BP and SAS oscillations. The overall increase in BP and SAS oscillations during slow breathing is driven by the respiratory component. Drop in cardiac component of BP amplitude evoked by slow-breathing may be perceived as a cardiovascular protective mechanism to avoid target organ damage. Further studies are warranted to assess long-term effects of slow breathing.

Tachycardia: The hidden cardiovascular risk factor in uncomplicated arterial hypertension

Early detection and management of elevated blood pressure is crucial in reducing the burden of cardiovascular disease (CVD). The importance of an absolute risk assessment and patient risk stratification has been highlighted in the European hypertension guidelines since 2003. Amongst numerous risk factors influencing patient prognosis, elevated heart rate (HR) has been indicated as important predictor of future risk of hypertension, coronary heart disease, sudden cardiac death, heart failure, CVD, stroke, total cancer and mortality. Given that resting HR can be easily determined in clinical practice and modified by lifestyle changes as well as beta-blocker therapy, it seems reasonable that lowering resting HR should be a potential target to reduce disease burden and premature mortality. However, there is a lack of outcome studies of HR lowering in tachycardia-related hypertension. This review outlines the underlying mechanisms of early course hypertension pathophysiology with the critical role of the sympathetic nervous system activation, the prognostic significance of fast HR and the mechanistic rationale for the use of non-pharmacological approaches and/or highly long-acting cardioselective beta-blockers with some consideration given to betaxolol properties.

Slow breathing improves cardiovascular reactivity to mental stress and health-related quality of life in heart failure patients with reduced ejection fraction

BACKGROUND

Previous studies have demonstrated therapeutic benefits of slow breathing (SLOWB) in chronic heart failure (HF) but its impact on cardiovascular reactivity in response to laboratory stressors remains unknown.

METHODS

Using device-guided breathing this study explored the acute and long-term effects of SLOWB on hemodynamic responses to handgrip, mental and cold pressor tests, and health-related quality of life (QoL) in stable HF patients with reduced ejection fraction (HFrEF) who had received all available optimal drug and device therapies. Blood pressure (BP) and heart rate (HR) were measured in 21 patients with HFrEF (23.9 ± 5.9%) at rest, during laboratory stressors, before and after acute SLOWB, and 12 weeks after SLOWB home training (30 min daily). Health-related QoL (MacNew questionaries) was assessed before and 12 weeks after SLOWB home training.

RESULTS

Resting BP significantly increased in response to three laboratory stressors. Pressor and cardiac changes during mental stress were greater than responses to the handgrip test (p < 0.05). Mental stress also produced a greater HR change than cold pressor test (p < 0.05). Both acute and long-term SLOWB significantly reduced BP and HR responses to mental stress (p < 0.05), but not to isometric and cold pressor tests. SLOWB improved scores of all domains of QoL (p < 0.05) at 12 weeks follow-up.

CONCLUSIONS

These findings demonstrate that SLOWB reduces acute and chronic effects of cardiovascular reactivity to mental stress and improves various aspects of health-related QoL in patients with severe HFrEF. Whether stress reduction and psychological changes achieved with SLOWB may translate to improved outcomes in HFrEF warrants further exploration.