Cardiovascular autonomic modulation during passive heating protocols: a systematic review.

Objective.To conduct a systematic review of the possible effects of passive heating protocols on cardiovascular autonomic control in healthy individuals.Approach.The studies were obtained from MEDLINE (PubMed), LILACS (BVS), EUROPE PMC (PMC), and SCOPUS databases, simultaneously. Studies were considered eligible if they employed passive heating protocols and investigated cardiovascular autonomic control by spontaneous methods, such as heart rate variability (HRV), systolic blood pressure variability (SBPV), and baroreflex sensitivity (BRS), in healthy adults. The revised Cochrane risk-of-bias tool (RoB-2) was used to assess the risk of bias in each study.Main results.Twenty-seven studies were included in the qualitative synthesis. Whole-body heating protocols caused a reduction in cardiac vagal modulation in 14 studies, and two studies reported both increased sympathetic modulation and vagal withdrawal. Contrariwise, local-heating protocols and sauna bathing seem to increase cardiac vagal modulation. A reduction of BRS was reported in most of the studies that used whole-body heating protocols. However, heating effects on BRS remain controversial due to methodological differences among baroreflex analysis and heating protocols.Significance.Whole-body heat stress may increase sympathetic and reduce vagal modulation to the heart in healthy adults. On the other hand, local-heating therapy and sauna bathing seem to increase cardiac vagal modulation, opposing sympathetic modulation. Nonetheless, further studies should investigate acute and chronic effects of thermal therapy on cardiovascular autonomic control.

Acute high-intensity interval exercise versus moderate-intensity continuous exercise in heated water-based on hemodynamic, cardiac autonomic, and vascular responses in older individuals with hypertension.

OBJECTIVES: This crossover study design aimed to assess hemodynamic, cardiac autonomic, and vascular responses to high-intensity interval (HIIE) vs moderate-intensity continuous exercise (MICE) in older individuals with hypertension. METHODS: Twenty (67 ± 7 y) older individuals with hypertension were randomly assigned to perform HIIE, MICE, or control (CON) sessions in the heated swimming pool (30-32°C). Blood pressure (BP), arterial stiffness, endothelial reactivity, and heart rate variability (HRV) were measured pre, post, and 45 min (recovery) after each intervention followed by 24-h ambulatory BP and HRV. RESULTS: One single aerobic exercise session was not effective to provoke post-exercise hypotension and vascular improvements. HIIE was superior to MICE and CON to increasing parasympathetic modulation at post and recovery. Exercise sessions showed to disturb the autonomic system at nighttime compared to CON. CONCLUSIONS: These results may have important implications in water-based therapy and the elderly with hypertension.

Effects of a mindfulness-based intervention on mindfulness, stress, salivary alpha-amylase and cortisol in everyday life.

A large body of literature has shown the effectiveness of mindfulness-based interventions (MBI) on stress-reduction. However, little is known about their effects on psychobiological stress-markers in daily life through an ecological momentary assessment approach. Our study examines the effects of MBI on state mindfulness, perceived stress, and indicators of sympathetic-nervous-system (saliva alpha-amylase, sAA) and hypothalamic-pituitary-adrenal-axis (saliva cortisol, sCort) activation in daily life. Twenty-eight individuals participated in a three-month MBI (IG) and were compared to 46 controls (CG). An ecological momentary assessment (EMA) was used to assess mindfulness, stress, sAA and sCort at six measurements per day on two days each before and after the MBI. Multilevel-modeling was used to analyze the data on a moment-to-moment and averaged day-level. The IG showed decreased sAA levels (AUCg) from pre to post, while the CG showed increases. Furthermore, diurnal decreases in sCort (AUCi) were pronounced in the IG compared to the CG. On a momentary basis, mindfulness was associated with lower stress and sAA levels, but not sCort. As such, we show that MBI can reduce sympathetic and to a lesser extent hypothalamic-pituitary-adrenal activation in daily life. Increased mindfulness can momentarily decrease stress and stress-related autonomic activation with implications for health. Our results emphasize the importance of brief interventions that can be easily integrated into everyday life.

Benefits from one session of deep and slow breathing on vagal tone and anxiety in young and older adults.

Anxiety is recognized as a major health issue and is quite prevalent among older adults. An efficient way to manage anxiety is abdominal breathing. Breathing exercises seem to reduce anxiety and to increase parasympathetic activity assessed by HRV indexes. Yet, the effect of abdominal breathing on physiological stress (HRV) and anxiety in older adults remains poorly understood. Therefore, the aim of this study is to test the effects of deep and slow breathing (DSB, low inhale/exhale ratio) on physiological stress and anxiety in older adults (n = 22) in comparison with younger ones (n = 25). DSB increased significantly HFpower and reduced state anxiety in both younger and older adults. Interestingly, the increased in HF power was significantly higher among older adults than younger ones. As expected, the ratio inhale/exhale being not equal, RMSSD did not increase following DSB. Thus, we provide evidence suggesting that DSB is more beneficial to older adults than younger ones to restore vagal outflow. Despite future work being required, those results provide relevant clinical application leads to manage state anxiety among older adults and to promote successfull aging.

Heart Rate Variability and Long Chain n-3 Polyunsaturated Fatty Acids in Chronic Kidney Disease Patients on Haemodialysis: A Cross-Sectional Pilot Study.

Low heart rate variability (HRV) is independently associated with increased risk of sudden cardiac death (SCD) and all cardiac death in haemodialysis patients. Long chain n-3 polyunsaturated fatty acids (LC n-3 PUFA) may exert anti-arrhythmic effects. This study aimed to investigate relationships between dialysis, sleep and 24 h HRV and LC n-3 PUFA status in patients who have recently commenced haemodialysis. A cross-sectional study was conducted in adults aged 40-80 with chronic kidney disease (CKD) stage 5 (n = 45, mean age 58, SD 9, 20 females and 25 males, 39% with type 2 diabetes). Pre-dialysis blood samples were taken to measure erythrocyte and plasma fatty acid composition (wt % fatty acids). Mean erythrocyte omega-3 index was not associated with HRV following adjustment for age, BMI and use of ß-blocker medication. Higher ratios of erythrocyte eicosapentaenoic acid (EPA) to docosahexaenoic acid (DHA) were associated with lower 24 h vagally-mediated beat-to-beat HRV parameters. Higher plasma EPA and docosapentaenoic acid (DPAn-3) were also associated with lower sleep-time and 24 h beat-to-beat variability. In contrast, higher plasma EPA was significantly related to higher overall and longer phase components of 24 h HRV. Further investigation is required to investigate whether patients commencing haemodialysis may have compromised conversion of EPA to DHA, which may impair vagally-mediated regulation of cardiac autonomic function, increasing risk of SCD.

Early changes of immunoreactivity to orexin in hypothalamus and to RFamide peptides in brainstem during the development of hypertension.

Baroreflex sensitivity (BRS) is an important function of the nervous system and essential for maintaining blood pressure levels in the physiological range. In hypertension, BRS is decreased both in man and animals. Although increased sympathetic activity is thought to be the main cause of decreased BRS, hence the development of hypertension, the BRS is regulated by both sympathetic (SNS) and parasympathetic (PNS) nervous system. Here, we analyzed neuropeptide changes in the lateral hypothalamus (LH), which favours the SNS activity, as well as in PNS nuclei in the brainstem of spontaneously hypertensive rats (SHR) and their normotensive controls (Wistar Kyoto rats- WKY). The analyses revealed that in the WKY rats the hypothalamic orexin system, known for its role in sympathetic activation, showed a substantial decrease when animals age. At the same time, however, such a decrease was not observed when hypertension developed in the SHR. In contrast, Neuropeptide FF (NPFF) and Prolactin Releasing Peptide (PrRP) expression in the PNS associated Nucleus Tractus Solitarius (NTS) and Dorsal Motor Nucleus of the Vagus (DMV) diminished substantially, not only after the establishment of hypertension but also before its onset. Therefore, the current results indicate early changes in areas of the central nervous system involved in SNS and PNS control of blood pressure and associated with the development of hypertension.

Neural Mechanisms and Therapeutic Opportunities for Atrial Fibrillation.

Atrial fibrillation (AF) is the most common cardiac arrhythmia and is associated with an increased risk of all-cause mortality and complications. The autonomic nervous system (ANS) plays a central role in AF, with the heart regulated by both extrinsic and intrinsic properties. In the extrinsic ANS, the sympathetic fibers are derived from the major paravertebral ganglia, especially the stellate ganglion (SG), which is a source of cardiac sympathetic innervation since it connects with multiple intrathoracic nerves and structures. The major intrinsic ANS is a network of axons and ganglionated plexi that contains a variety of sympathetic and parasympathetic neurons, which communicate with the extrinsic ANS. Simultaneous sympathovagal activation contributes to the development of AF because it increases calcium entry and shortens the atrial action potential duration. In animal and human studies, neuromodulation methods such as electrical stimulation and renal denervation have indicated potential benefits in controlling AF in patients as they cause SG remodeling and reduce sympathetic outflow. This review focuses on the neural mechanisms relevant to AF and the recent developments of neuromodulation methods for AF control.

Real-life dental examination elicits physiological responses different to visual and auditory dental-related stimuli.

BACKGROUND: Previous studies on dental anxiety have examined the psychophysiological responses evoked in dentally anxious subjects by dental-related stimuli, but not during a real-life dental examination, which was achieved in the present study. METHODS: The heart rate, skin conductance level, and heart rate variability of 25 subjects with dental anxiety and 25 healthy controls were examined. Anxiety was determined by the Modified Dental Anxiety Scale and the Dental Anxiety Scale-Revised. The psychophysiological reactions of the two groups were compared during exposure to dental-related pictures, dental-related sounds, and an actual examination in a dental surgery. RESULTS: All the dental-related stimuli provoked an increase in heart rate, i.e. visual stimuli (p<0.001; 95% CI 0.98-3.95 bpm), auditory stimuli (p<0.001; 95% CI 1.34-4.99 bpm), and a dental examination (p<0.001; 95% CI 1.26-5.39 bpm). Dental-related pictures provoked inferior skin conductance level changes compared to dental-related sounds and the dental examination (visual modality vs auditory p<0.001; 95% CI 0.039-0.152; visual modality vs examination p<0.001; 95% CI 0.083-0.275). Heart rate variability manifested in a complex pattern of responses to the dental examination. However, when exposed to all three dental-related stimuli presentation conditions, the heart rate (F = 0.352, p = 0.556), skin conductance level (F = 0.009, p = 0.926), and heart rate variability parameters of subjects with dental anxiety did not differ in comparison to the healthy controls. CONCLUSIONS: This pilot study represents an evaluation of psychophysiological reactions during a real-life dental examination compared to single modality stimuli, and shows that a real-life dental examination provokes an increase in heart rate, heart rate variability and skin conductance level. Additionally, autonomic responses did not differ between the experimental and control groups. The key issue for future studies is the effect of real-life situations on the physiological and psychological state of the subjects, which should be considered when planning new research and studied in depth.

Electroacupuncture improves cardiac function and reduces infarct size by modulating cardiac autonomic remodeling in a mouse model of myocardial ischemia.

BACKGROUND: Sympathetic and parasympathetic nerve remodeling play an important role in cardiac function after myocardial ischemia (MI) injury. Increasing evidence indicates that electroacupuncture (EA) can regulate cardiac function by modulating the autonomic nervous system (ANS), but little is known about its effectiveness on neural remodeling post-MI. OBJECTIVES: To investigate the role of EA in ANS remodeling post-MI. METHODS: Adult male C57/BL6 mice were equally divided into the Control (Ctrl), MI and EA groups after generating the MI model by ligating the left anterior descending (LAD) coronary artery. Echocardiography and 2,3,5-triphenyltetrazolium (TTC) staining were employed to evaluate cardiac function and infarct size after EA treatment for five consecutive days. Serum norepinephrine (NE) levels were measured by ELISA to quantify sympathetic activation. Then, ANS remodeling was detected by immunohistochemistry (IHC), RT-qPCR, and Western blotting. RESULTS: Our preliminary findings showed that EA increased ejection fraction and fractional shortening and reduced infarct area after MI injury. Serum NE levels in the EA group were significantly decreased compared with those in the MI group. IHC staining results demonstrated that the density of growth associated protein (GAP)43 and tyrosine hydroxylase (TH) positive nerve fibers in the EA group were decreased with increased choline acetyltransferase (CHAT) and vesicular acetylcholine transporter (VACHT). Meanwhile, the results verified that mRNA and protein expression of GAP43 and TH were significantly inhibited by EA treatment in the MI mice, accompanied by elevated CHAT and VACHT. CONCLUSIONS: EA treatment could improve cardiac function and reduce infarct size by modulating sympathetic and parasympathetic nerve remodeling post-MI, thus helping the cardiac ANS reach a new balance to try to protect the heart from further possible injury.

Neuroscientific therapies for atrial fibrillation.

The cardiac autonomic nervous system (ANS) plays an integral role in normal cardiac physiology as well as in disease states that cause cardiac arrhythmias. The cardiac ANS, comprised of a complex neural hierarchy in a nested series of interacting feedback loops, regulates atrial electrophysiology and is itself susceptible to remodelling by atrial rhythm. In light of the challenges of treating atrial fibrillation (AF) with conventional pharmacologic and myoablative techniques, increasingly interest has begun to focus on targeting the cardiac neuraxis for AF. Strong evidence from animal models and clinical patients demonstrates that parasympathetic and sympathetic activity within this neuraxis may trigger AF, and the ANS may either induce atrial remodelling or undergo remodelling itself to serve as a substrate for AF. Multiple nexus points within the cardiac neuraxis are therapeutic targets, and neuroablative and neuromodulatory therapies for AF include ganglionated plexus ablation, epicardial botulinum toxin injection, vagal nerve (tragus) stimulation, renal denervation, stellate ganglion block/resection, baroreceptor activation therapy, and spinal cord stimulation. Pre-clinical and clinical studies on these modalities have had promising results and are reviewed here.

Effect of aromatherapy on autonomic nervous system regulation with treadmill exercise-induced stress among adolescents.

INTRODUCTION: Stress is a major health issue in adolescents owing to the important transitions experienced during this period. Aromatherapy is an effective method for the reduction of stress in adolescents. PURPOSE: The aims of this study were to examine the effect of aromatherapy on the regulation of the autonomic nervous system (ANS) along with stress relief and to explore the effect of aromatherapy on adolescents with different levels of stress. METHODS: This quasi-experimental study comprised three types of treatments: control (no essential oil), pure essential oil therapy (sandalwood), and blended essential oil therapy (sandalwood-lavender). The heart rate variability (HRV) was calculated to evaluate the post-exercise recovery of the ANS to the baseline level in the recruited adolescents. To examine the efficiency of aromatherapy, Friedman test was used to assess the significance of difference in all parameters (i.e., mean heart rate, SDNN, normalized LF, normalized HF, and LF/HF) between baseline and after exercise among the three treatment conditions. RESULTS: The participants comprised 43 junior college students (8 males and 35 females) with a mean age of 18.21 ± 0.99. Significant differences in changes of two HRV parameters (normalized LF and LF/HF) were associated with both essential oil therapies compared to those in the control group (p<0.05), and one more HRV parameter (normalized HF) exhibited significant difference related to blended essential oil therapy compared to that of the control group. Besides, changes in two HRV parameters (mean heart rate and normalized HF) of both essential oil therapies in the low level stress subgroup showed significant differences compared to those of the control group (p<0.05). CONCLUSIONS: This study demonstrated that aromatherapy could be used for ANS regulation with stress-relieving effects in adolescents. The participants with a low stress level appeared to respond better to the blended essential oil therapy, whereas those with medium to high levels of stress appeared to respond poorly to aromatherapy compared to the control.

Evolving Cardiac Electrical Therapies for Advanced Heart Failure Patients.

Symptomatic heart failure (HF) patients despite optimal medical therapy and advances such as invasive hemodynamic monitoring remain challenging to manage. While cardiac resynchronization therapy remains a highly effective therapy for a subset of HF patients with wide QRS, a majority of symptomatic HF patients are poor candidates for such. Recently, cardiac contractility modulation, neuromodulation based on carotid baroreceptor stimulation, and phrenic nerve stimulation have been approved by the US Food and Drug Administration and are emerging as therapeutic options for symptomatic HF patients. This state-of-the-art review examines the role of these evolving electrical therapies in advanced HF.

Local Passive Heat for the Treatment of Hypertension in Autonomic Failure.

Background Supine hypertension affects a majority of patients with autonomic failure; it is associated with end-organ damage and can worsen daytime orthostatic hypotension by inducing pressure diuresis and volume loss during the night. Because sympathetic activation prevents blood pressure (BP) from falling in healthy subjects exposed to heat, we hypothesized that passive heat had a BP-lowering effect in patients with autonomic failure and could be used to treat their supine hypertension. Methods and Results In Protocol 1 (n=22), the acute effects of local heat (40-42°C applied with a heating pad placed over the abdomen for 2 hours) versus sham control were assessed in a randomized crossover fashion. Heat acutely decreased systolic BP by -19±4 mm Hg (versus 3±4 with sham, P<0.001) owing to decreases in stroke volume (-18±5% versus -4±4%, P=0.013 ) and cardiac output (-15±5% versus -2±4%, P=0.013). In Protocol 2 (proof-of-concept overnight study; n=12), we compared the effects of local heat (38°C applied with a water-perfused heating pad placed under the torso from 10 pm to 6 am) versus placebo pill. Heat decreased nighttime systolic BP (maximal change -28±6 versus -2±6 mm Hg, P<0.001). BP returned to baseline by 8 am. The nocturnal systolic BP decrease correlated with a decrease in urinary volume (r=0.57, P=0.072) and an improvement in the morning upright systolic BP (r=-0.76, P=0.007). Conclusions Local heat therapy effectively lowered overnight BP in patients with autonomic failure and supine hypertension and offers a novel approach to treat this condition. Future studies are needed to assess the long-term safety and efficacy in improving nighttime fluid loss and daytime orthostatic hypotension. Registration URL: https://www.clinicaltrials.gov; Unique identifiers: NCT02417415 and NCT03042988.

Autonomic Dysfunction and Neurohormonal Disorders in Atrial Fibrillation.

Atrial fibrillation (AF) is the most commonly diagnosed arrhythmia and eludes an efficacious cure despite an increasing prevalence and a significant association with morbidity and mortality. In addition to an array of clinical sequelae, the origins and propagation of AF are multifactorial. In recent years, the contribution from the autonomic nervous system has been an area of particular interest. This review highlights the relevant physiology of autonomic and neurohormonal contributions to AF origin and maintenance, the current state of the literature on targeted therapies, and the path forward for clinical interventions.

Dietary supplementation with L-carnosine improves patient-reported outcomes, autonomic nervous system performance, and brain metabolism in 3 adult patients with multiple sclerosis.

This pilot trial reports the effects of L-carnosine administration on autonomic nervous system performance, brain metabolism, and various patient- and clinician-reported outcomes in a case series of patients with multiple sclerosis (MS). We hypothesized that medium-term L-carnosine supplementation would improve selected patient- and clinician-reported outcomes in MS patients, with no negative effects on self-reported side effects. L-carnosine (2 g/day) was administered orally for 8 weeks in 2 women and one man suffering from MS. The intensity of symptoms and signs of MS after L-carnosine administration diminished in 5 out of 7 domains in CASE 1, in 3 out of 7 domains in CASE 2, and one domain in CASE 3; general fatigue was reduced in all 3 cases at the follow-up. This was accompanied by an improved walking distance to exhaustion in all patients, with values improved for 51.1% in CASE 1, 19.5% in CASE 2, and 2.1% in CASE 3 at 8-week follow-up. Tests of autonomic cardiovascular reflexes demonstrate normalized parasympathetic modulation and balanced sympathetic function after L-carnosine intervention in all MS cases. An increase in serum total antioxidant capacity (TAC) was found at 8-week follow-up in all patients (from 4.6 to 49.6%); this was accompanied by lower blood lactate at post-administration in all cases (23.5% on average). Single-voxel 1.5 T MR spectroscopy revealed increased brain choline-contained compounds (18.9% on average), total creatine (21.2%), and myo-inositol levels (12.3%) in girus cinguli at 8-week follow-up in all MS cases. This case study demonstrates that an 8-week intervention with L-carnosine appears to be a safe and beneficial therapeutic strategy with regard to the reduction of presence and severity of symptoms of MS.

The effect of remote ischemic postconditioning on autonomic function in patients with acute ischemic stroke: A Randomized Controlled Trail.

OBJECTIVE: The evidence for the effect of remote ischemic postconditioning(RIpostC) on autonomic function in patients with acute ischemic stroke(AIS) is lacking and the neural mechanism underlying the protection of RIpostC remains speculative. This trial was aimed to evaluated the efficiency of RIpostC on autonomic function in AIS patients. DESIGN: One hundred and six AIS patients were included in this prospective, randomized, placebo-controlled trial. Patients in intervention group (n = 57) received 4 cycles of alternating inflation (cuff inflation to 200 mmHg) and deflation for 5 min on healthy upper arm once a day for 30 days. The control group underwent a sham inflation and deflation cycles. Autonomic function was evaluated by heart rate variability (HRV). RESULTS: All HRV parameters except for the ratio of low frequency to high frequency (P = 0.101) increased significantly with time (P < 0.001) in the two groups. The value of standard deviation of all normal R-R intervals(SDNN) and high frequency at day7 and day30 and the value of the percent of difference between adjacent normal R-R intervals (pNN50) at day 30 in RIpostC group was significantly higher than that of the sham-RIpostC group(P < 0.05). A significant time-by-group interaction was observed in SDNN、pNN50、and high frequency over time between two groups (P < 0.05). CONCLUSIONS: 30-day RIpostC could improve autonomic function in AIS patients through the enhancement of the total autonomic nerve activity and vagus nerve activity. The mechanism of RIpostC mediating autonomic function needs to be further investigated.

Autonomic nervous system changes detected with peripheral sensors in the setting of epileptic seizures.

A better understanding of the early detection of seizures is highly desirable as identification of an impending seizure may afford improved treatments, such as antiepileptic drug chronotherapy, or timely warning to patients. While epileptic seizures are known to often manifest also with autonomic nervous system (ANS) changes, it is not clear whether ANS markers, if recorded from a wearable device, are also informative about an impending seizure with statistically significant sensitivity and specificity. Using statistical testing with seizure surrogate data and a unique dataset of continuously recorded multi-day wristband data including electrodermal activity (EDA), temperature (TEMP) and heart rate (HR) from 66 people with epilepsy (9.9 ± 5.8 years; 27 females; 161 seizures) we investigated differences between inter- and preictal periods in terms of mean, variance, and entropy of these signals. We found that signal mean and variance do not differentiate between inter- and preictal periods in a statistically meaningful way. EDA signal entropy was found to be increased prior to seizures in a small subset of patients. Findings may provide novel insights into the pathophysiology of epileptic seizures with respect to ANS function, and, while further validation and investigation of potential causes of the observed changes are needed, indicate that epilepsy-related state changes may be detectable using peripheral wearable devices. Detection of such changes with wearable devices may be more feasible for everyday monitoring than utilizing an electroencephalogram.

Effect of voluntary breathing exercises on stable coronary artery disease in heart rate variability and rate-pressure product: a study protocol for a single-blind, prospective, randomized controlled trial.

BACKGROUND: At present, China has more than 11 million patients with stable coronary heart disease and this is becoming a major public health problem. The pathological changes of coronary heart disease can lead to dysfunction of the cardiac autonomic nervous system, which increases the risk of complications such as malignant arrhythmia (ventricular flutter, ventricular fibrillation, etc.), heart rate, systolic blood pressure, and rate-pressure product (RPP), which is highly correlated with myocardial oxygen consumption and indirectly reflects myocardial blood supply and oxygen consumption. Although the guidelines recommend that such patients take drugs to reduce heart rate and myocardial oxygen consumption, the clinical control of heart rate is still not ideal. Thus, in this trial, we will use voluntary breathing exercises as the strategy of exercise rehabilitation for patients with stable coronary artery disease (SCAD), in order to increase the vagus nerve activity and/or reduce the sympathetic nervous activity, help maintain or rebuild the balance of plant nerve system, improve the time-domain index of heart rate variability, reduce the burden on the heart, and relieve patients' anxiety and other negative emotions. METHODS: This is a 6-month single-blind, randomized controlled clinical trial that will be conducted in the First Affiliated Hospital of Soochow University. A total of 140 patients who fill out the Informed Consent Form are registered and randomized 1:1 into the Voluntary Breathing Exercises (VBE)-based clinical trial monitoring group (n = 70) or the Routine follow-up group (n = 70). The VBE-based clinical trial monitoring group is given VBE training on the basis of conventional treatment and health education, while the control group received conventional health education and follow-up. The primary outcomes will be measured heart rate variability and RPP. Secondary outcomes will include changes in Self-rating Anxiety Scale, total cholesterol, triglyceride, high-density lipoprotein, low-density lipoprotein, weight, and body mass index. DISCUSSION: This trial will carry out scientific respiratory exercise for patients with SCAD, which belongs to the category of active secondary prevention for patients, and changes from remedial to pre-protective. VBE is easy to operate and is not limited by time and place. It is important and meaningful to carry out VBE for patients with SCAD. This study will provide considerable evidence for further large-scale trials and alternative strategies for the rehabilitation nursing of patients with SCAD. TRIAL REGISTRATION: Chinese Clinical Trials Registry, 1900024043 . Registered on 23 June 2019.

Effects of electroacupuncture on stress-induced gastric dysrhythmia and mechanisms involving autonomic and central nervous systems in functional dyspepsia.

Electroacupuncture (EA) is widely used as an effective method to treat stress-related disorders. However, its mechanisms remain largely unknown. The aim of this study was to investigate the effects and mechanisms of EA on gastric slow wave (GSW) dysrhythmia and c-Fos expression in the nucleus of the solitary tract (NTS) induced by stress in a rodent model of functional dyspepsia (FD). Rats in the neonatal stage were treated using intragastric iodoacetamide. Eight weeks later, the rats were implanted with electrodes in the stomach for the measurement of GSW and electrodes into accupoints ST36 for EA. Autonomic functions were assessed by spectral analysis of heart rate variability. Rats were placed for 30 min in a cylindrical plastic tube for acute restraint stress. The involvement of a central afferent pathway was assessed by measuring c-Fos-immunoreactive cells in the NTS. 1) EA normalized restraint stress-induced impairment of GSW in FD rats. 2) EA significantly increased vagal activity (P = 0.002) and improved sympathovagal balance (P = 0.004) under stress in FD rats. 3) In FD rats under restraint stress, plasma norepinephrine concentration was increased substantially (P < 0.01), which was suppressed with EA. 4) The EA group showed increased c-Fos-positive cell counts in the NTS compared with the sham EA group (P < 0.05) in FD rats. Acute restraint stress induces gastric dysrhythmia in a rodent model of FD. EA at ST36 improves GSW under stress in FD rats mediated via the central and autonomic pathways, involving the NTS and vagal efferent pathway.

Autonomic Brain Centers and Pathophysiology of COVID-19.

Accumulating data have now shown strong evidence that COVID-19 infection leads to the occurrence of neurological signs with different injury severity. Anosmia and agueusia are now well documented and included in the criteria list for diagnosis, and specialists have stressed that doctors screen COVID-19 patients for these two signs. The eventual brainstem dysregulation, due to the invasion of SARS CoV-2, as a cause of respiratory problems linked to COVID-19, has also been extensively discussed. All these findings lead to an implication of the central nervous system in the pathophysiology of COVID-19. Here we provide additional elements that could explain other described signs like appetite loss, vomiting, and nausea. For this, we investigated the role of brainstem structures located in the medulla oblongata involved in food intake and vomiting control. We also discussed the possible pathways the virus uses to reach the brainstem, i.e., neurotropic and hematogenous (with its two variants) routes.