Explore the vast range of titles available.

This proof-of-concept study evaluated the acute effects of transcutaneous auricular vagus nerve stimulation (taVNS) on cardiac vagal activity in people living with HIV. Twenty-one men living with HIV on antiretroviral therapy participated in a single-blind, crossover clinical trial. Participants underwent two counterbalanced stimulation conditions (taVNS and sham) with a 48-hour washout period. Cardiac vagal activity was assessed using vagally-mediated heart rate variability (vmHRV) indices, including the root mean square of successive differences (rMSSD) and the percentage of differences between adjacent normal intervals greater than 50 ms (pNN50), recorded before, during, and after stimulation. No significant changes in vmHRV parameters were observed over time or between conditions. These findings suggest that an acute taVNS session does not modulate cardiac vagal activity in people living with HIV. We discuss potential explanations for these results and highlight considerations for future research on taVNS as a non-pharmacological approach to autonomic modulation.

To determine whether pretreatment vagal efficiency (VE), respiratory sinus arrhythmia, and heart period can predict pain improvement with auricular neurostimulation in pediatric functional abdominal pain disorders. A total of 92 adolescents with functional abdominal pain disorders underwent a 4-week randomized, double-blinded, sham-controlled auricular neurostimulation trial. Electrocardiogram-derived variables at baseline were used to predict pain using mixed effects modeling. A 3-way interaction (95% confidence intervals: 0.004-0.494) showed that the treatment group subjects with low baseline VE had lower pain scores at week 3. There was no substantial change in the placebo or high VE treatment group subjects. This effect was supported by a significant correlation between baseline VE and degree of pain reduction only in the treatment group. Impaired cardiac vagal regulation measured by VE predicts pain improvement with auricular neurostimulation.

Background: The modulation of the autonomic nervous system’s activity, particularly increasing its parasympathetic tone, is of significant interest in clinical physiotherapy due to its potential benefits for stress-related conditions and recovery processes. This study evaluated the effectiveness of the addition of neurodynamics in enhancing parasympathetic activation in subjects with chronic stress. Methods: A clinical trial randomly assigned participants to a group with neurodynamics (6 bpm breathing protocol + manual therapy + neurodynamic technique) or a group without neurodynamics (6 bpm breathing protocol + manual therapy only). Metrics of heart rate variability (HRV), including the Mean Heart Rate (Mean HR), standard deviation of intervals between consecutive heartbeats (SDNN), Heart Rate Difference (Diff. HR), Root Mean Square of Successive Differences (RMSSD), number of intervals differing by more than 50 ms (NN50), percentage of consecutive NN intervals that differed by more than 50 ms (pNN50), and the high-frequency component measured in standardized units (HF), were assessed before, during, and after the intervention. Results: During the intervention, the group with neurodynamics showed significant changes in all variables except in the pNN50 and HF while the group without neurodynamics only showed improvements in the Mean HR, SDNN, and RMSSD. In the post-intervention phase, the group with neurodynamics maintained an increase in HRV while the group without neurodynamics experienced a decrease, suggesting an increase in sympathetic activity. Conclusions: Vagal nerve neurodynamics appear to represent an effective method for enhancing parasympathetic activation in patients with chronic stress. The results highlight the importance of a more comprehensive analysis of HRV variables in order to obtain a correct picture of the impact of interventions on the complex and multifaceted functioning of the autonomic nervous system.

Objectives Systemic inflammation is a potentially debilitating complication of thoracic surgeries with significant physical and economic morbidity. There is compelling evidence for the role of the central nervous system in regulating inflammatory processes through humoral mechanisms. Activation of the afferent vagus nerve by cytokines triggers anti-inflammatory responses. Peripheral electrical stimulation of the vagus nerve in vivo during lethal endotoxemia in rats inhibited tumor necrosis factor synthesis and prevented shock development. However, the vagal regulatory role of systemic inflammation after lung lobectomy is unknown. Methods One hundred patients who underwent lobectomy via thoracotomy were recruited and equally randomized to treated group or controls. Intermittent stimulation of the auricular branch of vagus nerve in the triangular fossa was applied in the treated group using neurostimulator V (Ducest ® , Germany), starting 24 h preoperatively and continued till the 4th postoperative day (POD). Inflammatory interleukins (IL) were analyzed using ELISA preoperatively, on the 1st and 4th POD. Results On the 1st POD, patients who underwent neurostimulation had reduced serum concentrations of CRP ( p  = 0.01), IL6 ( p  = 0.02) but elevated IL10 ( p  = 0.03) versus controls. On the 4th POD, serum concentrations of CRP, IL6 and IL10 were similar in both groups. Moreover, the treated group was associated with lower incidence of pneumonia ( p  = 0.04) and shorter hospitalization time ( p  = 0.04) versus controls. Conclusions Modulations in the brain stem caused by noninvasive transcutaneous stimulation of the vagus nerve after lung lobectomy attenuate the acute postsurgical inflammatory response by the regulation of IL6 and IL10, resulting in  reduced incidence of postoperative pneumonia and short hospitalization time. Clinical Trial Registry Number NCT03204968.

Background Borderline personality disorder (BPD) is considered a disorder of emotion regulation resulting from the expression of a biologically determined emotional vulnerability (that is, heightened sensitivity to emotion, increased emotional intensity/reactivity, and a slow return to emotional baseline) combined with exposure to invalidating environments. Vagal tone has been associated with activity in cortical regions involved in emotion regulation and a lower resting state of vagal tone has been observed in BPD patients relative to healthy controls. Non-invasive transcutaneous auricular vagus nerve stimulation (taVNS) has been shown to reduce temper outbursts in adults with Prader-Willi Syndrome, to enhance recognition of emotions in healthy students, and to improve depressive and anxiety symptoms. Furthermore, a single session of taVNS has been shown to acutely alter the recognition of facial expressions of negative valence in adolescents with MDD and increase emotion recognition in controls. However, the effect of taVNS on emotional vulnerability and regulation in individuals diagnosed with BPD has not been investigated. Our aims are to determine if taVNS is effective in acutely reducing emotional vulnerability and improve emotional regulation in BPD patients. Methods Forty-two patients will be randomized to a single session of taVNS or sham-taVNS while going through an affect induction procedure. It will consist of the presentation of one neutral and three negative affect-evoking 4-min-long videos in sequence, each of which is followed by a 4-min post-induction period during which participants will rate the quality and intensity of their current self-reported emotions (post-induction ratings) and the perceived effectiveness in managing their emotions during the video presentation. The rating of the current self-reported emotions will be repeated after every post-induction period (recovery ratings). Mixed models with individuals as random effect will be used to investigate the ratings at each stage of the study, taking into account the repeated measures of the same individuals at baseline, pre-induction, post-induction, and recovery. Discussion The study has potential to yield new insights into the role of vagal tone in emotion dysregulation in BPD and offer preliminary data on the effectiveness of taVNS as a possible non-invasive brain stimulation to treat a core symptom of BPD. Trial registration ClinicalTrials.gov NCT05892900. Retrospectively registered on Jun 07, 2023.

Imbalance between the parasympathetic and sympathetic nervous systems is a recognized contributor to progression of chronic heart failure. Current therapy with beta adrenergic antagonists is designed to moderate the up-regulation of norepinephrine and sympathetic effects; however, to date, there are no therapies that specifically address the withdrawal of parasympathetic influences on cardiac function and structure. In order to evaluate the impact of vagus nerve stimulation, an international multi-center randomized clinical trial (INOVATE-HF) has been designed to assess safety and efficacy of vagus nerve stimulation in symptomatic patients with heart failure on optimal medical therapy using the CardioFit System (BioControl Medical, Yehud, Israel). Up to 650 patients from 80 sites will be recruited and randomized in a 3:2 ratio to receive active treatment or standard optimal medical therapy. Inclusion criteria include left ventricular systolic dysfunction, the presence of New York Heart Association Class III symptoms, sinus rhythm, and QRS width less than 120 milliseconds. The study is powered to detect differences in the primary efficacy end point of all-cause mortality and heart failure hospitalization and 2 safety end points. Vagal nerve stimulation with CardioFit as a treatment for symptomatic heart failure is under active investigation as a novel approach to restore balance between the sympathetic and parasympathetic nervous systems. If shown to be safe and effective in decreasing heart failure events and mortality, this novel approach will impact the treatment paradigm for heart failure.

Reduced vagally mediated heart rate variability (VmHRV) has been reported in patients with chronic pain. In healthy persons, breathing with longer expiration relative to inspiration increases VmHRV at 12 breaths per minute. The present study aimed to determine the immediate effect of breathing with longer expiration relative to inspiration on VmHRV and mood states in patients with chronic pain. Fifty patients with chronic pain aged between 20 and 67 years were prospectively randomized as two groups with an allocation ratio of 1:1. The interventional group practiced breathing with metronome based visual cues, maintaining an inspiration to expiration ratio of 28:72 (i/e ratio, 0.38) at a breath rate of 12 breaths per minute. The average i/e ratio they attained based on strain gauge respiration recording was 0.685 (SD 0.48). The control group, which looked at the metronome without conscious breath modification had an average i/e ratio of 0.745 (SD 0.69). The VmHRV, respiration and self-reported mood states (using the Brief Mood Introspection Scale (BMIS)) were assessed. There was a significant increase in HF-HRV and RMSSD during low i/e breathing (repeated measures ANCOVA, Bonferroni adjusted post-hoc test, p < 0.05; in all cases). Self-reported mood states changed as follows: (i) following low i/e breathing positive-mood states increased while the aroused mood state decreased whereas (ii) following the control intervention the aroused mood state increased (repeated measure ANOVA, p < 0.05; in all cases). Hence breathing with prolonged expiration is possibly useful to increase VmHRV and improve self- reported mood states in patients with chronic pain.

Adolescents with autism present lower levels of cardiac vagal modulation. It was hypothesized that Heart Rate Variability Biofeedback (HRVB) increases cardiac vagal modulation in adolescents with autism, resulting in positive effects on physiological and psychosocial parameters. It was also hypothesized that home-based HRVB training is feasible. In a single-blind, randomized sham-controlled pilot trial, adolescents with autism performed supervised HRVB (n = 24) or sham training (n = 20). Subsequently, half of the adolescents received HRVB training at home, whereas the other subset did not practice. Physiological, cortisol and behavioral data were collected during stress-provoking assessments before and after each training period. Supervised HRVB resulted in a late increase in cardiac vagal modulation in adolescents with autism. Heart rate increased and cortisol decreased significantly immediately after supervised HRVB, but none of these effects remained after follow-up. Following supervised HRVB, no significant change in psychosocial functioning was found. Home-based HRVB was feasible, adolescents reported lower symptoms of stress, but a significant decrease in compliance rate was found. HRVB is feasible and effective in adolescents with autism given the late-emerging increases in cardiac vagal modulation and decrease in stress symptoms. Replicating this study with a larger sample and further exploration of the working mechanisms of HRVB are recommended. ClinicalTrials.gov, NCT04628715.

PurposeSuspension syndrome describes a potentially life-threatening event during passive suspension on a rope. The pathophysiological mechanism is not fully understood and optimal treatment unknown. We aimed to elucidate the pathophysiology and to give treatment recommendations.MethodsIn this experimental, randomized crossover trial, 20 healthy volunteers were suspended in a sit harness for a maximum of 60 min, with and without prior climbing. Venous pooling was assessed by measuring the diameter of the superficial femoral vein (SFV), lower leg tissue oxygenation (StO2) and by determining localized bioelectrical impedance. Hemodynamic response was assessed by measuring heart rate, blood pressure, stroke volume, and left ventricular diameters. Signs and symptoms of pre-syncope were recorded.ResultsTwelve (30%) out of 40 tests were prematurely terminated due to pre-syncopal symptoms (mean 44.7 min, minimum 13.4, maximum 59.7). SFV diameter increased, StO2 and the capacitive resistance of the cells decreased indicating venous pooling. Heart rate and blood pressure did not change in participants without pre-syncope. In contrast, in participants experiencing pre-syncope, heart rate and blood pressure dropped immediately before the event. All symptoms dissolved and values returned to normal within 5 min with participants in a supine position.ConclusionsSudden pre-syncope during passive suspension in a harness was observed in 30% of the tests. Blood pools in the veins of the lower legs; however, a vagal mechanism finally leads to loss of consciousness. Time to pre-syncope is unpredictable and persons suspended on a rope should be rescued and put into a supine position as soon as possible.

Application of cold to the face evokes potent bradycardia and a pressor response, similar to the diving reflex. However, the role of the baroreceptors in this response is unclear. Ten healthy controls and two patients with baroreflex impairment were recruited. A cold face test (CFT) was induced by the application of three cold packs (0.5 degrees C) to the face. Heart rate (ECG), blood pressure (Finapres) and skin temperature (forehead electrode) were recorded continuously. All data were analyzed using unpaired Students t-tests, and expressed as mean +/- SD. In all controls, CFT induced bradycardia. The mean onset latency was 5.6 +/- 4.6 s, and the maximal bradycardia was seen at 35.8 +/- 15.8 s. Systolic blood pressure increased in eight controls, with a mean onset latency of 18.8 +/- 16.6 s and a peak rise at 38.7 +/- 22.7 s. In the controls, bradycardia preceded the pressor response. The heart rate and blood pressure changes during CFT had a longer latency than baroreflex evoked responses. Moreover, one subject had bradycardia despite a fall in blood pressure. The two patients had abnormal Valsalva ratios and no change in heart rate during tilt, indicating impairment of the baroreflex. However, both their heart rate and blood pressure responses to CFT were normal. These data are further evidence of the limited role of the baroreflex in the autonomic responses to CFT. They suggest that the CFT may be of use in assessing the integrity of the efferent cardiovascular autonomic pathways in patients with suspected baroreflex impairment.