Heart rate variability, the vagus and calm.
Everything below was reached through this subject, not through the words you typed. Every row states how it was reached.
Research library, full list
201 to 225 of 1,007Randomised controlled trial of a 12 week yoga intervention on negative affective states, cardiovascular and cognitive function in post-cardiac rehabilitation patients.
Background: Negative affective states such as anxiety, depression and stress are significant risk factors for cardiovascular disease, particularly in cardiac and post-cardiac rehabilitation populations. Yoga is a balanced practice of physical exercise, breathing control and meditation that can reduce psychosocial symptoms as well as improve cardiovascular and cognitive function. It has the potential to positively affect multiple disease pathways and may prove to be a practical adjunct to cardiac rehabilitation in further reducing cardiac risk factors as well as improving self-efficacy and post-cardiac rehabilitation adherence to healthy lifestyle behaviours.
Method and design: This is a parallel arm, multi-centre, randomised controlled trial that will assess the outcomes of post- phase 2 cardiac rehabilitation patients assigned to a yoga intervention in comparison to a no-treatment wait-…
matched on Heart Rate (mesh), heart rate variability (text)
Self-compassion training modulates alpha-amylase, heart rate variability, and subjective responses to social evaluative threat in women.
A growing body of research has revealed that social evaluative stressors trigger biological and psychological responses that in chronic forms have been linked to aging and disease. Recent research suggests that self-compassion may protect the self from typical defensive responses to evaluation. We investigated whether brief training in self-compassion moderated biopsychological responses to the Trier Social Stress Test (TSST) in women. Compared to attention (placebo) and no-training control conditions, brief self-compassion training diminished sympathetic (salivary alpha-amylase), cardiac parasympathetic, and subjective anxiety responses, though not HPA-axis (salivary cortisol) responses to the TSST. Self-compassion training also led to greater self-compassion under threat relative to the control groups. In that social stress pervades modern life, self-compassion represents a promising a…
matched on Heart Rate (mesh), heart rate variability (text)
The effect of a single session of short duration heart rate variability biofeedback on EEG: a pilot study.
This pilot study examines the effect of heart rate variability (HRV) biofeedback on measures of electroencephalogram (EEG) during and immediately after biofeedback. Eighteen healthy males exposed to work-related stress, were randomised into an HRV biofeedback (BIO) or a comparative group (COM). EEG was recorded during the intervention and during rest periods before and after the intervention. Power spectral density in theta, alpha and beta frequency bands and theta/beta ratios were calculated. During the intervention, the BIO group had higher relative theta power [Fz and Pz (p < 0.01), Cz (p < 0.05)], lower fronto-central relative beta power (p < 0.05), and higher theta/beta [Fz and Cz (p < 0.01), Pz (p < 0.05)] than the COM group. The groups showed different responses after the intervention with increased posterior theta/beta (p < 0.05) in the BIO group and altered posterior relative th…
matched on Heart Rate (mesh), heart rate variability (text)
Oxytocin increases heart rate variability in humans at rest: implications for social approach-related motivation and capacity for social engagement.
Context: Oxytocin (OT) plays a key regulatory role in human social behaviour. While prior studies have examined the effects of OT on observable social behaviours, studies have seldom examined the effects of OT on psychophysiological markers such as heart rate variability (HRV), which provides an index of individual's motivation for social behaviour. Furthermore, no studies have examined the impact of OT on HRV under resting conditions, which provides an index of maximal capacity for social engagement.
Objective: To examine the effects of OT on HRV measures in healthy male participants while at rest. OT was hypothesised to increase HRV, compared to placebo, and that the effects would be greatest for a non-linear measure of HRV (the detrended fluctuation scaling exponent).
Methods: Twenty-one male participants were recruited for this study. Participants were non-smokers, not on any medicat…
matched on Heart Rate (mesh), heart rate variability (text)
Matter over mind: a randomised-controlled trial of single-session biofeedback training on performance anxiety and heart rate variability in musicians.
Background: Musical performance is a skilled activity performed under intense pressure, thus is often a profound source of anxiety. In other contexts, anxiety and its concomitant symptoms of sympathetic nervous system arousal have been successfully ameliorated with HRV biofeedback (HRV BF), a technique involving slow breathing which augments autonomic and emotional regulatory capacity.
Objective: This randomised-controlled study explored the impact of a single 30-minute session of HRV BF on anxiety in response to a highly stressful music performance.
Methods: A total of 46 trained musicians participated in this study and were randomly allocated to a slow breathing with or without biofeedback or no-treatment control group. A 3 Group×2 Time mixed experimental design was employed to compare the effect of group before and after intervention on performance anxiety (STAI-S) and frequency domai…
matched on Heart Rate (mesh), heart rate variability (text)
Heart rate variability biofeedback reduces food cravings in high food cravers.
Heart rate variability (HRV) biofeedback has been reported to increase HRV while decreasing symptoms in patients with mental disorders. In addition, associations between low HRV and lowered self-regulation were found in non-clinical samples, e.g., in individuals with strong chocolate cravings or unsuccessful dieting. The current study aimed at decreasing food cravings with HRV-biofeedback in individuals frequently experiencing such cravings. Participants (N = 56) with strong or low food cravings associated with a lack of control over eating were selected from the local community. Half of the participants with strong cravings (craving-biofeedback; n = 14) performed 12 sessions of HRV-biofeedback while the other half (craving-control; n = 14) and a group with low cravings (non-craving-control; n = 28) received no intervention. Subjective food cravings related to a lack of control over eati…
matched on Heart Rate (mesh), heart rate variability (text)
Langrish JP, Li X, Wang S, Lee MM, Barnes GD, Miller MR, Cassee FR, Boon NA, Donaldson K, Li J, Li L, Mills NL, Newby DE, Jiang L (2012)randomised controlled trialMEDLINE-indexed journal, not yet read by usEnvironmental health perspectives183 citations Reducing personal exposure to particulate air pollution improves cardiovascular health in patients with coronary heart disease.
Background: Air pollution exposure increases cardiovascular morbidity and mortality and is a major global public health concern.
Objectives: We investigated the benefits of reducing personal exposure to urban air pollution in patients with coronary heart disease.
Methods: In an open randomized crossover trial, 98 patients with coronary heart disease walked on a predefined route in central Beijing, China, under different conditions: once while using a highly efficient face mask, and once while not using the mask. Symptoms, exercise, personal air pollution exposure, blood pressure, heart rate, and 12-lead electrocardiography were monitored throughout the 24-hr study period.
Results: Ambient air pollutants were dominated by fine and ultrafine particulate matter (PM) that was present at high levels [74 μg/m³ for PM(2.5) (PM with aerodynamic diamater <2.5 µm)]. Consistent with traffic-derived…
matched on Heart Rate (mesh), heart rate variability (text)
Controlled exposure of healthy young volunteers to ozone causes cardiovascular effects.
Background: Recent epidemiology studies have reported associations between short-term ozone exposure and mortality. Such studies have previously reported associations between airborne particulate matter pollution and mortality, and support for a causal relationship has come from controlled-exposure studies that describe pathophysiological mechanisms by which particulate matter could induce acute mortality. In contrast, for ozone, almost no controlled-human-exposure studies have tested whether ozone exposure can modulate the cardiovascular system.
Methods and results: Twenty-three young healthy individuals were exposed in a randomized crossover fashion to clean air and to 0.3-ppm ozone for 2 hours while intermittently exercising. Blood was obtained immediately before exposure, immediately afterward, and the next morning. Continuous Holter monitoring began immediately before exposure and c…
matched on Heart Rate (mesh), heart rate variability (text)
Effect of slow abdominal breathing combined with biofeedback on blood pressure and heart rate variability in prehypertension.
Objective: Prehypertension is a new category designated by the Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC7) in 2003. Managing prehypertension with nonpharmacological intervention is possibly beneficial to the prevention of hypertension. In this study, we observed the effect of slow abdominal breathing combined with electromyographic (EMG) biofeedback training on blood pressure (BP) in prehypertensives and assessed the changes of heart rate variability (HRV) in order to find an optional intervention to prevent hypertension and acquire some experimental data to clarify the underlying neural mechanism.
Methods: Twenty-two (22) postmenopausal women with prehypertension were randomly assigned to either the experiment group or the control group. The experiment group performed 10 sessions of slow abdominal breat…
matched on Heart Rate (mesh), heart rate variability (text)
Brook RD, Urch B, Dvonch JT, Bard RL, Speck M, Keeler G, Morishita M, Marsik FJ, Kamal AS, Kaciroti N, Harkema J, Corey P, Silverman F, Gold DR, Wellenius G, Mittleman MA, Rajagopalan S, Brook JR (2009)randomised controlled trialMEDLINE-indexed journal, not yet read by usHypertension (Dallas, Tex. : 1979)349 citations Insights into the mechanisms and mediators of the effects of air pollution exposure on blood pressure and vascular function in healthy humans.
Fine particulate matter air pollution plus ozone impairs vascular function and raises diastolic blood pressure. We aimed to determine the mechanism and air pollutant responsible. The effects of pollution on heart rate variability, blood pressure, biomarkers, and brachial flow-mediated dilatation were determined in 2 randomized, double-blind, crossover studies. In Ann Arbor, 50 subjects were exposed to fine particles (150 microg/m(3)) plus ozone (120 parts per billion) for 2 hours on 3 occasions with pretreatments of an endothelin antagonist (Bosentan, 250 mg), antioxidant (Vitamin C, 2 g), or placebo. In Toronto, 31 subjects were exposed to 4 different conditions (particles plus ozone, particles, ozone, and filtered air). In Toronto, diastolic blood pressure significantly increased (2.9 and 3.6 mm Hg) only during particle-containing exposures in association with particulate matter concen…
matched on Heart Rate (mesh), heart rate variability (text)
Endurance training guided individually by daily heart rate variability measurements.
Purpose of this study was to test utility of heart rate variability (HRV) in daily endurance exercise prescriptions. Twenty-six healthy, moderately fit males were randomized into predefined training group (TRA, n = 8), HRV-guided training group (HRV, n = 9), and control group (n = 9). Four-week training period consisted of running sessions lasting 40 min each at either low- or high-intensity level. TRA group trained on 6 days a week, with two sessions at low and four at high intensity. Individual training program for HRV group was based on individual changes in high-frequency R-R interval oscillations measured every morning. Increase or no change in HRV resulted in high-intensity training on that day. If there was significant decrease in HRV (below reference value [10-day mean-SD] or decreasing trend for 2 days), low-intensity training or rest was prescribed. Peak oxygen consumption (VO(…
matched on Heart Rate (mesh), heart rate variability (text)
Post-resistance exercise hypotension, hemodynamics, and heart rate variability: influence of exercise intensity.
Unlabelled: The occurrence of post-exercise hypotension after resistance exercise is controversial, and its mechanisms are unknown. To evaluate the effect of different resistance exercise intensities on post-exercise blood pressure (BP), and hemodynamic and autonomic mechanisms, 17 normotensives underwent three experimental sessions: control (C-40 min of rest), low- (E40%-40% of 1 repetition maximum, RM), and high-intensity (E80%-80% of 1 RM) resistance exercises. Before and after interventions, BP, heart rate (HR), and cardiac output (CO) were measured. Autonomic regulation was evaluated by normalized low- (LF(R-R)nu) and high-frequency (HF(R-R)nu) components of the R-R variability. In comparison with pre-exercise, systolic BP decreased similarly in the E40% and E80% (-6 +/- 1 and -8 +/- 1 mmHg, P < 0.05). Diastolic BP decreased in the E40%, increased in the C, and did not change in the…
matched on Heart Rate (mesh), heart rate variability (text)
Heart rate variability biofeedback as a behavioral neurocardiac intervention to enhance vagal heart rate control.
Background: Patients with coronary heart disease (CHD) who experience depressed mood or psychological stress exhibit decreased vagal control of heart rate (HR), as assessed by spectral analysis of HR variability (HRV). Myocardial infarction and sudden cardiac death are independently associated with depression and stress, as well as impaired vagal HR control. This study examined whether a behavioral neurocardiac intervention to reduce stress or depression can augment cardiovagal modulation in CHD patients. We hypothesized that (1) cognitive-behavioral training with HRV biofeedback would augment vagal recovery from acute stress, and (2) vagal regulation of HR would be inversely associated with stress and depression after treatment.
Methods: This randomized controlled trial enrolled 46 CHD patients from 3 clinics of CHD risk reduction in Toronto and Vancouver, Canada. Subjects were randomiz…
matched on Heart Rate (mesh), heart rate variability (text)
Biofeedback and dance performance: a preliminary investigation.
Alpha-theta neurofeedback has been shown to produce professionally significant performance improvements in music students. The present study aimed to extend this work to a different performing art and compare alpha-theta neurofeedback with another form of biofeedback: heart rate variability (HRV) biofeedback. Twenty-four ballroom and Latin dancers were randomly allocated to three groups, one receiving neurofeedback, one HRV biofeedback and one no intervention. Dance was assessed before and after training. Performance improvements were found in the biofeedback groups but not in the control group. Neurofeedback and HRV biofeedback benefited performance in different ways. A replication with larger sample sizes is required.
matched on Heart Rate (mesh), heart rate variability (text)
Heart rate variability and generalized anxiety disorder during laboratory-induced worry and aversive imagery.
Background: To date only a few published studies have examined the effect of disorder-relevant stressors on heart rate variability (HRV) in participants meeting a clinical diagnosis of GAD, with conflicting results. The primary aim of this study was to determine if GAD is associated with lower HRV at rest, and whether vagal regulation during task varies by type (i.e., baseline, anticipation, imagery, or worry).
Methods: This study investigated resting cardiac vagal tone and vagal regulation in a sample of 40 participants with or without a validated diagnosis of generalized anxiety disorder (GAD). High-frequency heart rate variability (HF-HRV) was used to index cardiac vagal activity.
Results: GAD was associated with vagal withdrawal during both imagery and worry inductions, but no group differences in resting vagal tone or worry were observed.
Limitations: Methodological limitations incl…
matched on Vagus Nerve (mesh), Heart Rate (mesh), heart rate variability (text), vagal tone (text), Parasympathetic Nervous System (mesh), Heart Rate (keyword), Parasympathetic Nervous System (keyword)
Chronic baroreflex activation effects on sympathetic nerve traffic, baroreflex function, and cardiac haemodynamics in heart failure: a proof-of-concept study.
Aims: Heart failure (HF) pathophysiology is believed to be mediated by autonomic dysfunction, including chronic sympathoexcitation and diminished baroreflex sensitivity, which correlate with mortality risk. Baroreflex activation therapy (BAT) is a device-based treatment providing chronic baroreflex activation through electrical stimulation of the carotid sinus. BAT chronically reduces sympathetic activity in resistant hypertension. The purpose of this investigation is to determine BAT effects in clinical HF.
Methods and results: In a single-centre, open-label evaluation, patients with NYHA class III HF, EF <40%, optimized medical therapy, and ineligible for cardiac resynchronization received BAT for 6 months. Efficacy was assessed with serial measurement of muscle sympathetic nerve activity (MSNA) and clinical measures of quality of life and functional capacity. Eleven patients participa…
matched on Baroreflex (mesh), Sympathetic Nervous System (mesh), Sympathetic Nervous System (keyword)
Balancing the autonomic nervous system to reduce inflammation in rheumatoid arthritis.
Imbalance in the autonomic nervous system (ANS) has been observed in many established chronic autoimmune diseases, including rheumatoid arthritis (RA), which is a prototypic immune-mediated inflammatory disease (IMID). We recently discovered that autonomic dysfunction precedes and predicts arthritis development in subjects at risk of developing seropositive RA. In addition, RA patients with relatively high vagus nerve tone (higher parasympathetic parameters, measured by heart rate variability) respond better to antirheumatic therapies. Together, these data suggest that the ANS may control inflammation in humans. This notion is supported by experimental studies in animal models of RA. We have found that stimulation of the so-called cholinergic anti-inflammatory pathway by efferent electrical vagus nerve stimulation (VNS) or pharmacological activation of the alpha7 subunit of nicotinic ace…
matched on Autonomic Nervous System (mesh), Vagus Nerve Stimulation (mesh), heart rate variability (text)
Rates and Predictors of Seizure Freedom With Vagus Nerve Stimulation for Intractable Epilepsy.
Background: Neuromodulation-based treatments have become increasingly important in epilepsy treatment. Most patients with epilepsy treated with neuromodulation do not achieve complete seizure freedom, and, therefore, previous studies of vagus nerve stimulation (VNS) therapy have focused instead on reduction of seizure frequency as a measure of treatment response.
Objective: To elucidate rates and predictors of seizure freedom with VNS.
Methods: We examined 5554 patients from the VNS therapy Patient Outcome Registry, and also performed a systematic review of the literature including 2869 patients across 78 studies.
Results: Registry data revealed a progressive increase over time in seizure freedom after VNS therapy. Overall, 49% of patients responded to VNS therapy 0 to 4 months after implantation (≥50% reduction seizure frequency), with 5.1% of patients becoming seizure-free, while 63% o…
matched on Vagus Nerve Stimulation (mesh)
Sun F, Wu S, Guo S, Yu K, Yang Z, Li L, Zhang Y, Quan X, Ji L, Zhan S (2015)systematic reviewMEDLINE-indexed journal, not yet read by usDiabetes research and clinical practice236 citations Impact of GLP-1 receptor agonists on blood pressure, heart rate and hypertension among patients with type 2 diabetes: A systematic review and network meta-analysis.
Aims: To evaluate current evidence of glucagon-like peptide-1 receptor agonists (GLP-1RAs) on blood pressure, heart rate, and hypertension in patients with type 2 diabetes.
Methods: Medline, Embase, the Cochrane library, and the website www.clinicaltrials.gov were searched on April 5th, 2014. Randomized-controlled trials with available data were included if they compared GLP-1RAs with placebo and traditional antidiabetic drugs in patients with type 2 diabetes with duration ≥ 12 weeks. Weighted mean difference for blood pressure and heart rate, odds ratio (OR) for hypertension were calculated by random-effect model. Network meta-analysis was performed to supplement direct comparisons.
Results: Sixty trials with 14 treatments were included. Compared with placebo, insulin, and sulfonylureas, GLP-1RAs decreased systolic blood pressure with range from -1.84 mmHg (95% CI: -3.48 to -0.20) to -4…
matched on Heart Rate (mesh), Heart Rate (keyword)
Moffet HH (2006)systematic reviewMEDLINE-indexed journal, not yet read by usBMC complementary and alternative medicine63 citations How might acupuncture work? A systematic review of physiologic rationales from clinical trials.
Background: Scientific interest in acupuncture has led numerous investigators to conduct clinical trials to test the efficacy of acupuncture for various conditions, but the mechanisms underlying acupuncture are poorly understood.
Methods: The author conducted a PubMed search to obtain a fair sample of acupuncture clinical trials published in English in 2005. Each article was reviewed for a physiologic rationale, as well as study objectives and outcomes, experimental and control interventions, country of origin, funding sources and journal type.
Results: Seventy-nine acupuncture clinical trials were identified. Twenty-six studies (33%) offered no physiologic rationale. Fifty-three studies (67%) posited a physiologic basis for acupuncture: 33 (62% of 53) proposed neurochemical mechanisms, 2 (4%) segmental nervous system effects, 6 (11%) autonomic nervous system regulation, 3 (6%) local eff…
matched on Autonomic Nervous System (mesh)
α7-cholinergic receptor mediates vagal induction of splenic norepinephrine.
Classically, sympathetic and parasympathetic systems act in opposition to maintain the physiological homeostasis. In this article, we report that both systems work together to restrain systemic inflammation in life-threatening conditions such as sepsis. This study indicates that vagus nerve and cholinergic agonists activate the sympathetic noradrenergic splenic nerve to control systemic inflammation. Unlike adrenalectomy, splenectomy and splenic neurectomy prevent the anti-inflammatory potential of both the vagus nerve and cholinergic agonists, and abrogate their potential to induce splenic and plasma norepinephrine. Splenic nerve stimulation mimics vagal and cholinergic induction of norepinephrine and re-establishes neuromodulation in α7 nicotinic acetylcholine receptor (α7nAChR)-deficient animals. Thus, vagus nerve and cholinergic agonists inhibit systemic inflammation by activating th…
matched on Vagus Nerve Stimulation (mesh), Parasympathetic Nervous System (mesh), Sympathetic Nervous System (mesh)
Gritty people try harder: grit and effort-related cardiac autonomic activity during an active coping challenge.
Grit, a recently proposed personality trait associated with persistence for long-range goals, predicts achievement in a wide range of important life outcomes. Using motivational intensity theory, the present research examined the physiological underpinnings of grit during an active coping task. Forty young adults completed the Short Grit Scale and worked on a self-paced mental effort task. Effort-related autonomic nervous system (ANS) activity was assessed using impedance cardiography, which yielded measures of sympathetic activity (pre-ejection period; PEP) and parasympathetic activity (respiratory sinus arrhythmia; RSA). Multilevel models revealed that people high on the Perseverance of Effort subscale showed autonomic coactivation: both PEP and RSA became stronger during the task, reflecting higher activity of both ANS divisions. The Consistency of Interest subscale, in contrast, pred…
matched on Heart Rate (mesh), respiratory sinus arrhythmia (text)
Moving beyond belief: A narrative review of potential biomarkers for transcutaneous vagus nerve stimulation.
Transcutaneous vagus nerve stimulation (tVNS) is a non-invasive neurostimulation technique that is currently being tested as a potential treatment for a myriad of neurological and psychiatric disorders. However, the working mechanisms underlying tVNS are poorly understood and it remains unclear whether stimulation activates the vagus nerve for every participant. Finding a biological marker of tVNS is imperative, as it can help guide research on clinical applications and can inform researchers on optimal stimulation sites and parameters to further optimize treatment efficacy. In this narrative review, we discuss five potential biomarkers for tVNS and review currently available evidence for these markers for both invasive and tVNS. While some of these biomarkers hold promise from a theoretical perspective, none of the potential biomarkers provide clear and definitive indications that tVNS …
matched on Vagus Nerve Stimulation (mesh), Heart Rate (mesh), Parasympathetic Nervous System (mesh), Transcutaneous Electric Nerve Stimulation (mesh)
The pulse of inflammation: heart rate variability, the cholinergic anti-inflammatory pathway and implications for therapy.
Biological therapeutics targeting TNF, IL-1 and IL-6 are widely used for treatment of rheumatoid arthritis, inflammatory bowel disease and a growing list of other syndromes, often with remarkable success. Now advances in neuroscience have collided with this therapeutic approach, perhaps rendering possible the development of nerve stimulators to inhibit cytokines. Action potentials transmitted in the vagus nerve culminate in the release of acetylcholine that blocks cytokine production by cells expressing acetylcholine receptors. The molecular mechanism of this cholinergic anti-inflammatory pathway is attributable to signal transduction by the nicotinic alpha 7 acetylcholine receptor subunit, a regulator of the intracellular signals that control cytokine transcription and translation. Favourable preclinical data support the possibility that nerve stimulators may be added to the future ther…
matched on Vagus Nerve (mesh), Heart Rate (mesh), heart rate variability (text)
Samuel M, Khairy P, Champagne J, Deyell MW, Macle L, Leong-Sit P, Novak P, Badra-Verdu M, Sapp J, Tardif JC, Andrade JG (2021)randomised controlled trialMEDLINE-indexed journal, not yet read by usJAMA cardiology61 citations Association of Atrial Fibrillation Burden With Health-Related Quality of Life After Atrial Fibrillation Ablation: Substudy of the Cryoballoon vs Contact-Force Atrial Fibrillation Ablation (CIRCA-DOSE) Randomized Clinical Trial.
Importance: Patients with atrial fibrillation (AF) have impaired health-related quality of life primarily owing to symptoms related to AF episodes; however, quality of life can be influenced by AF therapies, AF complications, the frequency of follow-up visits and hospitalizations, illness perceptions, and patient factors, such as anxiety or depression.
Objective: To determine the association between change in AF burden and quality of life in the year following ablation.
Design, setting, and participants: The current study is a secondary analysis of a prospective, parallel-group, multicenter, single-masked randomized clinical trial (Cryoballoon vs Irrigated Radiofrequency Catheter Ablation: Double Short vs Standard Exposure Duration [CIRCA-DOSE] study), which took place at 8 Canadian centers. Between September 2014 and July 2017, 346 patients older than 18 years with symptomatic, primaril…
matched on Heart Rate (mesh), Electrocardiography (mesh)