Sympathetic Autonomic Nervous System Research Articles

Autonomic modulation by SGLT2i or DPP4i in patients with diabetes favors cardiovascular outcomes as revealed by skin sympathetic nerve activity

BackgroundSodium-glucose cotransporter 2 inhibitors (SGLT2i) and dipeptidyl peptidase-4 inhibitors (DPP4i) are important second-line treatments for patients with type 2 diabetes mellitus (T2DM). Patients taking SGLT2i have favorable cardiovascular outcomes via various mechanisms, including autonomic nervous system (ANS) modulation. This study aimed to use neuro-electrocardiography (neuECG) to test the effects of SGLT2i or DPP4i on the ANS.MethodsPatients with T2DM, who did not reach target hemoglobin (Hb)A1C levels despite metformin treatment, were enrolled. SGLT2i or DPP4i were prescribed randomly unless a compelling indication was present. NeuECG and heart rate were recorded for 10 min before and after a 3-month treatment. The patients were treated according to standard practice and the obtained data for skin sympathetic nerve activity (SKNA) and ANS entropy were analyzed offline.ResultsWe enrolled 96 patients, of which 49 received SGLT2i and 47 received DPP4i. The baseline parameters were similar between the groups. No adverse event was seen during the study period. In the burst analysis of SKNA at baseline, all parameters were similar. After the 3-month treatment, the firing frequency was higher in SGLT2i group (0.104 ± 0.045 vs 0.083 ± 0.033 burst/min, p < 0.05), with increased long firing duration (7.34 ± 3.66 vs 5.906 ± 2.921, p < 0.05) in 3-s aSKNA scale; the other parameters did not show any significant change. By symbolic entropy, the most complex patterns (Rank 3) were found to be significantly higher in SGLT2i-treated patients than in DDP4i-treated group (0.084 ± 0.028 vs 0.07 ± 0.024, p = 0.01) and the direction of change in Rank 3, after SGLT2i treatment, was opposite to that observed in the DDP4i group (0.012 ± 0.036 vs. −0.005 ± 0.037, p = 0.024). Our findings demonstrated the favorable autonomic modulation by SGLTi and the detrimental effects of DPP4i on ANS.ConclusionWe demonstrated the autonomic modulation by SGLTi and DPP4i using SKNA in patients with DM, which might provide insights into the favorable outcomes of SGLT2i. Furthermore, we refined the analytical methods of neuECG, which uses SKNA to evaluate autonomic function.

Relationships between subjective experience, electroencephalogram, and heart rate variability during a series of cosmetic behavior.

Cosmetic behavior is an important daily activity, especially for women, because it increases visual attractiveness, self-confidence, and positive emotions. However, it is unknown whether a relationship exists between physiological measures and subjective experiences during the series of cosmetic behaviors. Electroencephalograms (EEG) and electrocardiograms (ECG) from thirty female participants who were asked to look in a mirror after applying skincare, as well as base, eye, cheek, and lip makeup were recorded. The price range of cosmetic products was also considered. Subjective evaluations of the skin surface, emotions, and self-confidence were equally measured after looking in the mirror at each step of the cosmetic behavior. Linear mixed models were fitted to examine whether the subjective experience could be explained by the variety of cosmetic products and/or physiological responses. The subjective evaluation was summarized into the following three factors using a factor analysis: self-confidence, hedonic perception, and negative emotion. Each theta-band (4-6 Hz) power, alpha-band (8-13 Hz) power of the EEG, and heart rate variability measures were subjected to a principal component analysis separately. The linear mixed models indicated that the variation in the self-confidence score and the negative emotion score was explained only by the steps of cosmetic behaviors, that is, self-confidence increased while negative emotions decreased as the steps of cosmetic behaviors proceeded. On the other hand, the hedonic perception score was explained by the interaction of the steps of cosmetic behaviors and price, indicating that positive tactile perception and positive emotion were higher when luxury cosmetic products were applied than when affordable products were applied. Furthermore, the model indicated that the hedonic perception score was positively associated with the alpha-band power over occipital sites whereas sympathetic nervous system activity was negatively associated with the alpha-band power over lateral central sites. These results suggest that positive perceptual and emotional experiences are associated with greater attention to somatosensory information than to visual information and sympathetic autonomic nervous system activities. The current results also emphasize the possibility of using physiological measurements as objective measures of cosmetic behavior.

Lipid profile, inflammatory biomarkers, endothelial dysfunction, and heart rate variability in adolescents with type 1 diabetes. A case-control study among UAE population

BackgroundType 1 diabetes mellitus (T1DM) is an autoimmune disease characterized by the chronic inflammation and cause of endothelial dysfunction (ED). Heart rate variability (HRV) is a marker of sympathetic and parasympathetic autonomic nervous system dysfunction. We investigated the association of lipid profile, inflammatory biomarkers, endothelial dysfunction, and heart rate variability in adolescents with T1DM among UAE population. MethodIn this case-control study we recruited 126 adolescents (13–22 years) from Abu Dhabi, UAE (United Arab Emirates). Demographic, anthropometric, blood and urine samples were collected after an overnight fasting. HRV measurements were determined per Task Force recommendations. Independent t-test or Mann-Whitney U test and Pearson's Chi-squared test were used to compare groups. Adjusted conditional logistic regression model was used to identify the determinants independently associated with T1DM. ResultsThe mean ages in control (n = 47) and patient (n = 79) groups were 17.5 ± 4.6 and 18.6 ± 4.8 years, respectively. A family history of diabetes and waist and hip circumferences significantly differed between the groups (p = 0.030 and 0.010). The patients with T1DM exhibited significantly higher levels of atherogenic markers than control. Endothelial dysfunction biomarkers such as levels of sICAM-1 (p < 0.001), adiponectin (p < 0.001) and 25-hydroxyvitamin D (p < 0.001) were significantly different in the control group compared with those in the T1DM group. There was a significant difference in SDNN intervals, NN50, pNN50, and SD1/SD2 among the two groups. In adjusted analysis, total cholesterol (adjusted Odds Ratio (aOR): 2.78, 95 % CI:1.37–5.64; p = 0.005), LDL (2.66, 95%CI:1.19–5.92; p = 0.017), and triglycerides (5.51, 95%CI:1.57–19.41; p = 0.008) were significantly associated with developing T1DM. The HRV indicators were significantly associated with decrease odds of T1DM after controlling for SBP, BMI, and family history of DM. ConclusionIn this study, adolescents with T1DM showed a significant association with lipid profile, ED, and HRV compared with controls. Thus, an early attention to diabetes control is required to reduce the risk of cardiac autonomic neuropathy leading to various cardiovascular diseases.

Linear and non‑linear indices of vagal nerve in relation to sex and inflammation in patients with Covid‑19.

Hyperinflammation is one of the most important pathophysiological risk factors for poor prognosis in patients with coronavirus disease-2019 (Covid-19). Low vagal neuro-immune modulation can lead into this kind of immune dysregulation. The association between vagal activity, sex and inflammatory markers were investigated in patients with Covid-19. A total of 19 patients with Covid-19 were included in the present study. Vagus nerve activity was indexed by heart rate variability (HRV) derived from electrocardiogram at hospital admission. Linear HRV parameters included the root mean square of successive RR interval differences (RMSSD) and high-frequency HRV (HF-HRV), while non-linear parameters included 2 UV%. Immune/inflammatory parameters included C-reactive protein (CRP), interleukin-6 (IL-6), neutrophil/lymphocyte ratio (NLR), systemic inflammatory index (SII), and procalcitonin (PCT). It has been revealed that both linear HRV indices HF-HRV and RMSSD, are significantly negatively correlated with CRP and IL-6, independent of age. The non-linear index of 2 UV% is significantly negatively correlated with NLR and SII, which reflect subtle changes in the response of immunocompetent cells. Patients that received high-flow nasal oxygen therapy had significantly higher IL-6 and CRP levels and lower levels of HF-HRV and RMSSD. These patients also had a significantly longer length of stay in hospital (LOS) than patients receiving low-flow oxygen therapy. Men had higher plasma PCT levels and longer LOS in hospital than women, and PCT statistically explained (mediated) the association between sex and LOS. The present study showed different correlations of linear and non-linear vagal indexes of HRV and inflammatory markers in patients with Covid-19. Significant sex differences in certain inflammatory markers were also observed, which may very well verify previous findings of poor prognosis in men with Covid-19. HRV reflects a continuous interaction between the sympathetic and parasympathetic autonomic nervous systems, which are affected by mental or physical stress, and certain disease states. The increased sympathetic and decreased parasympathetic vagal tone contribute to a higher risk of diseases associated with inflammation, cardiovascular disease, cancer, pulmonary diseases and other pathologies, including infectious diseases such as Covid-19. The present study showed that higher RMSSD (a marker of vagal activity) in Covid-19 patients is associated with lower levels of inflammatory biomarkers, a lower need for treatment and is negatively correlated with intensive care unit admission, leading to a shorter hospital stay. These findings support the idea that activation of vagus nerve may help certain Covid-19 patients by reducing the cytokine storm and excessive inflammation.

Pilot study shows skin-to-skin care with parents improves heart rate variability in preterm infants in the neonatal intensive care unit.

Skin-to-skin care in the newborn intensive care unit typically lasts for short periods of time and enhances breastfeeding, attachment, and parental self-esteem. Heart rate variability (HRV) increases with gestational age and is a measure of maturation of parasympathetic vs. sympathetic autonomic nervous system activity. HRV measurements may be useful in capturing changes in autonomic regulation in response to skin-to-skin care. To analyze the effects of skin-to-skin care on HRV in preterm infants receiving respiratory support. We hypothesized that skin-to-skin care would result in a more mature pattern of parasympathetic activity. In this prospective crossover study, infants <30 weeks' gestation and 1-6 weeks postnatal age had HRV recorded for 30 min before, during, and after skin-to-skin care sessions. HRV characteristics analyzed included the standard deviation of the normal-to-normal interval (SDNN), the root mean squared of successive differences of normal-to-normal intervals (RMSSD), and the standard deviation of decelerations (SDDec). 10 infants between 25 5/7-29 6/7 weeks gestational age and 7-41 days postnatal age completed 22 sessions while receiving respiratory support (positive pressure ventilation or nasal cannula oxygen). Two measures of HRV (SDNN and RMSSD) were significantly decreased by the end of the skin-to-skin sessions, compared to pre-session values. SDNN decreased from a median of 10.44 ms before the session to 6.70 ms after being placed back in bed (p < 0.05), with RMSSD decreasing from a median of 6.80 ms before the session to 4.32 ms while being held at the end of 30 min (p < 0.05). Skin-to-skin care with a parent resulted in a more mature autonomic nervous system pattern in preterm infants receiving respiratory support, suggesting physiologic benefit for the infant. No adverse events were seen during any session.

Mutual Information between EDA and EEG in Multiple Cognitive Tasks and Sleep Deprivation Conditions.

Sleep deprivation, a widespread phenomenon that affects one-third of normal American adults, induces adverse changes in physical and cognitive performance, which in turn increases the occurrence of accidents. Sleep deprivation is known to increase resting blood pressure and decrease muscle sympathetic nerve activity. Monitoring changes in the interplay between the central and autonomic sympathetic nervous system can be a potential indicator of human's readiness to perform tasks that involve a certain level of cognitive load (e.g., driving). The electroencephalogram (EEG) is the standard to assess the brain's activity. The electrodermal activity (EDA) is a reflection of the general state of arousal regulated by the activation of the sympathetic nervous system through sweat gland stimulation. In this work, we calculated the mutual information between EDA and EEG recordings in order to consider linear and non-linear interactions and provide an insight of the relationship between brain activity and peripheral autonomic sympathetic activity. We analyzed EEG and EDA data from ten participants performing four cognitive tasks every two hours during 24 h (12 trials). We decomposed EEG data into delta, theta, alpha, beta, and gamma spectral components, and EDA into tonic and phasic components. The results demonstrate high values of mutual information between the EDA and delta component of EEG, mainly in working memory tasks. Additionally, we found an increase in the theta component of EEG in the presence of fatigue caused by sleep deprivation, the alpha component in tasks demanding inhibition and attention, and the delta component in working memory tasks. In terms of the location of brain activity, most of the tasks report high mutual information in frontal regions in the initial trials, with a trend to decrease and become uniform for all the nine analyzed EEG channels as a consequence of the sleep deprivation effect. Our results evidence the interplay between central and sympathetic nervous activity and can be used to mitigate the consequences of sleep deprivation.

Changes in cardiac function in Navy divers during four days of successive dives in very cold diving conditions.

There is limited knowledge of cumulative effect of repetitive cold-water diving on cardiac function. Single cold dives cause some known cardiological risks, such as malign arrhythmia, due to a concurrent activation of the sympathetic and parasympathetic autonomic nervous system. A previous study from warmer water dives has shown that successive dives cause a decrease in vagal tone and a less responsive cardiovascular system. The aim of this study was to evaluate changes in cardiac function with 2D echocardiography during 4 days of diving in near-freezing water. Left ventricle systolic function measures did not show any uniform changes. E/A ratio seemed to decrease successively with the number of dives. The diastolic tissue velocity of relaxing basal septum (e') showed a decreasing trend as well. Diastolic blood pressure seemed to increase from predive (mean: 83 RR mmHg) to postdive values (mean: 87 RR mmHg) (p=NS). Heart rate decreased significantly from predive (mean: 71 bpm, range: 56-103) to postdive values (mean: 60 bpm, range: 37-88) (p < 0.03). The study was conducted in very cold condition and with limited number of divers. Results of this preliminary study suggested a decreasing trend in left ventricular diastolic function in successive cold dives. Cumulative changes in cardiac function may cause health risks that need to be considered during cold water diving operations.

Methods for eliciting and measuring behavioral and physiological consequences of stress and uncertainty in virtual reality

Military operations are characterized by high levels of stress and uncertainty, and these states can influence cognitive and physical performance outcomes. These states, however, can be difficult to reliably induce in laboratory contexts, making it challenging to quantify and model their influences on perceptual and cognitive processes underlying performance on applied tasks. Herein we describe the development and validation of a novel scenario-based virtual reality methodology, the decision making under uncertainty and stress (DeMUS) scenario, that accomplishes four primary goals. First, it induces physiological and biochemical stress responses through a threat of shock manipulation. Second, it induces transient states of uncertainty by manipulating stimulus clarity in a perceptual decision-making task. Third, it generates several performance metrics regarding recognition memory, spatial orienting, threat classification, and marksmanship decision making. Finally, the task combines behavioral, physiological, and biochemical measures to provide a more comprehensive understanding of how stress and uncertainty influence applied task performance. To provide an initial validation of the scenario and its associated tasks and measures, we conducted a pilot study (n= 18) involving stress induction and cognitive performance assessment. Analyses revealed that: 1) the DeMUS scenario elicited tonic and phasic biochemical (salivary alpha amylase and cortisol) and physiological (heart rate, pupil diameter) stress responses, 2) the scenario elicited variable sympathetic autonomic nervous system and hypothalamic-pituitary adrenal (HPA) axis responses, and 3) stress influenced some measures of memory and decision-making in both negative and positive directions. Continuing research will assess individual- and group-level predictors of performance on these virtual reality tasks, and emerging performance enhancement techniques that can help military personnel sustain performance during stressful operations.

Chronic reduction of store operated Ca2+ entry is viable therapeutically but is associated with cardiovascular complications.

Loss of function mutations in store-operated Ca2+ entry (SOCE) are associated with severe paediatric disorders in humans, including combined immunodeficiency, anaemia, thrombocytopenia, anhidrosis and muscle hypotonia. Given its central role in immune cell activation, SOCE has been a therapeutic target for autoimmune and inflammatory diseases. Treatment for such chronic diseases would require prolonged SOCE inhibition. It is, however, unclear whether chronic SOCE inhibition is viable therapeutically. Here we address this issue using a novel genetic mouse model (SOCE hypomorph) with deficient SOCE, nuclear factor of activated T cells activation, and T cell cytokine production. SOCE hypomorph mice develop and reproduce normally and do not display muscle weakness or overt anhidrosis. They do, however, develop cardiovascular complications, including hypertension and tachycardia, which we show are due to increased sympathetic autonomic nervous system activity and not cardiac or vascular smooth muscle autonomous defects. These results assert that chronic SOCE inhibition is viable therapeutically if the cardiovascular complications can be managed effectively clinically. They further establish the SOCE hypomorph line as a genetic model to define the therapeutic window of SOCE inhibition and dissect toxicities associated with chronic SOCE inhibition in a tissue-specific fashion. KEY POINTS: A floxed stromal interaction molecule 1 (STIM1)hypomorph mouse model was generated with significant reduction in Ca2+ influx through store-operated Ca2+ entry (SOCE), resulting in defective nuclear translocation of nuclear factor of activated T cells, cytokine production and inflammatory response. The hypomorph mice are viable and fertile, with no overt defects. Decreased SOCE in the hypomorph mice is due to poor translocation of the mutant STIM1 to endoplasmic reticulum-plasma membrane contact sites resulting in fewer STIM1 puncta. Hypomorph mice have similar susceptibility to controls to develop diabetes but exhibit tachycardia and hypertension. The hypertension is not due to increased vascular smooth muscle contractility or vascular remodelling. The tachycardia is not due to heart-specific defects but rather seems to be due to increased circulating catecholamines in the hypomorph. Therefore, long term SOCE inhibition is viable if the cardiovascular defects can be managed clinically.

Relationships of autonomic dysfunction with disease severity and neuropathic pain features in fibromyalgia: is it really a sympathetically maintained neuropathic pain?

BackgroundThe pathophysiology of fibromyalgia (FM) involves many mechanisms including central nervous system sensitization theory, autonomic nervous system (ANS) dysfunction, and recently small fiber neuropathy. While the small fiber neuropathy itself can cause ANS dysfunction and neuropathic pain (NP), it is still unknown whether ANS problems have an association with severity of disease and NP in patients with FM. The aim of this study was to evaluate ANS dysfunction in FM patients and to explore possible associations of ANS dysfunction with disease severity and NP.MethodsTwenty-nine FM patients and 20 healthy controls were included in this cross-sectional study. Participants were tested using sympathetic skin responses (SSR) and R-R interval variation analyses for sympathetic and parasympathetic ANS dysfunction, respectively. Disease severity and somatic symptoms of patients with FM were evaluated using the ACR-2010 scales and Fibromyalgia Impact Questionnaire, and NP symptoms were evaluated using the Pain Detect Questionnaire and Douleur Neuropathique questionnaire.ResultsFM patients were found to have ANS dysfunction characterized by increased sympathetic response and decreased parasympathetic response. SSR amplitudes were found to be correlated with a more severe disease. Although non-significant, NP severity tended to be associated with a decrease in sympathetic and parasympathetic activities.ConclusionsANS dysfunction may play a role in the pathophysiology of FM. The trend of decreased ANS functions in FM patients exhibiting NP contradicts the notion that FM is a sympathetically maintained NP and may be explained with small fiber involvement.

Exploration biochimique de la médullosurrénale

AbstractCatecholamines (epinephrine and norepinephrine) are hormones that regulate arterial pressure and are neurotransmitters of sympathetic autonomous nervous system. They are secreted in excess by chromaffin tumors of adrenal medulla (phaeochromocytoma) or sympathetic lymph nodes (paraganglioma). The catecholamines as well as their metabolites (metanephrines, vanillylmandelic acid and homovanillic acid), and also dopamine, are measured in both plasma and urines by assays based on separation by high performance liquid chromatography (HPLC) and often identified by tandem mass spectrometry (MS/MS). Pre-analytic conditions are difficult because they should not stimulate secretion of catecholamines. Actual recommendations request first measurement of total metanephrines in urines although HPLC-MS/MS can measure separately free forms in both plasma and urines. Chromogranin A allows easily screening, but not yet available. Positive diagnosis and therapeutic nursing of these tumors need the all analytical arsenal from metanephrines to catecholamines their-self.

A personified approach to the treatment of vegetative disorders in patients with prevential stomach conditions using Pure Purr complex

Background. Indicators of heart rate variability are reliable and objective indicators of the tone of the autonomic nervous system (ANS), which reflects changes in the psycho-emotional state of man against the background of stress. Stress management programs include a variety of relaxation techniques and cognitive behavioral therapy. Therefore, the purpose of the study was to optimize the treatment of patients with chronic atrophic gastritis with autonomic disorders using software and hardware for parasympathetic activation of the ANS. Materials and methods. Indicators of heart rate variability were studied in 80 patients with chronic atrophic gastritis based on the results of PRECISE diagnostics, which allowed to identify patients with hypersympathicotonia and treat them with 10 sessions on Pure Purr software and hardware complex to assess the dynamics of heart rate variability. Results. 72.7% of patients with chronic atrophic gastritis, who showed a decrease in heart rate variability due to activation of the sympathetic tonic ANS and insufficient activity of its parasympathetic tonic, breakdown of adaptation, lack of stress and functional reserves of the body were treated with neurostimulation. After treatment, positive dynamics was determined in the form of a significant increase in heart rate variability by increasing its components due to the parasympathetic nervous system, which prevents increased sympathetic influences and improves disease and prognosis by normalizing adaptation, functional reserves and stress resistance. Conclusions. Treatment of patients with chronic atrophic gastritis with autonomic disorders should be comprehensive with the inclusion of hardware with neurostimulation software aimed at reducing hypersympathicotonia with increasing adaptive capacity of the body.

Heart rate variability as a marker of autonomic nervous system activity in young people with eosinophilic and non-eosinophilic asthma

Objective An imbalance in autonomic nervous system (ANS) activity may play a role in asthma, but it is unclear whether this is associated with specific pathophysiology. This study assessed ANS activity by measuring heart rate variability (HRV) in eosinophilic (EA) and non-eosinophilic asthma (NEA) and people without asthma. Methods HRV, combined hypertonic saline challenge/sputum induction, exhaled nitric oxide (FeNO), skin prick tests to measure atopy, and spirometry tests were conducted in teenagers and young adults (14–21 years) with (n = 96) and without (n = 72) generally well-controlled asthma. HRV parameters associated with sympathetic and parasympathetic ANS branches were analyzed. EA and NEA were defined using a 2.5% sputum eosinophil cut-point. Airway hyperreactivity (AHR) was defined as ≥15% reduction in FEV1 following saline challenge. Results HRV parameters did not differ between asthmatics and non-asthmatics or EA and NEA. They were also not associated with markers of inflammation, lung function or atopy. However, increased absolute low frequency (LFµs2; representing increased sympathetic nervous system (SNS) activity) was found in asthmatics who used β-agonist medication compared to those who did not (median: 1611, IQR 892–3036 vs 754, 565–1592; p < 0.05) and increased normalized low frequency (LF nu) was found in those with AHR compared to without AHR (64, 48–71 vs 53, 43–66; p < 0.05). Conclusion ANS activity (as measured using HRV analysis) is not associated with pathophysiology or inflammatory phenotype in young asthmatics with generally well-controlled asthma. However, enhanced SNS activity can be detected in asthmatics with AHR or who use β-agonist medication.

Application of Physiological Autonomic Activity Tracking GUI and Computational Algorithms for Measuring Persistent Vagal Nerve Dysfunction After Recovery from SARS‐CoV‐2 Infection

Post‐Acute Sequelae of SARS‐CoV‐2 infection (PASC) is now recognized as a constellation of symptoms such as postural hypotension, anxiety, and “brain fog” in addition to autonomic nervous system dysfunction such as tachycardia and labile hypertension. Better quantification of these conditions, specifically, autonomic nervous system dysfunction, is desired for future diagnostics, treatment modalities, and gaining a further understanding of PASC. This research has led to application of a novel autonomic activity tracking algorithm and GUI suite from previous work, see Figure 1, to study the physiological autonomic activity in six patients who had recovered from acute SARS‐CoV‐2 infection a mean of six months prior but were still experiencing symptoms. By measuring skin sympathetic nervous activity (SKNA), heart rate variability, and the cutaneous electrogastrogram (EGG), all before and after a water meal challenge, the data was fed into a custom analysis pipeline, shown in Figure 1. Each of the PASC patients were compared to a mean response of 34 healthy controls, each undergoing a 20‐minute baseline recording and another 20‐minute recording after ingestion of an 8 oz water test meal. All six patients showed significantly abnormal heart rate variability on frequency domain analysis in predominantly the low frequency (LF) and very low frequency (VLF) bands, and less so in the high frequency (HF) band, suggesting sympathetic nerve dysfunction. Three patients showed a significant decrease in SKNA while two showed a significant increase. All patients showed an abnormal cutaneous EGG. As shown in Figure 2, the temporal responses of aSKNA, VLF, LF, HF, and EGG for the PASC patients revealed that on average they were statistically different (p<0.05) from the healthy controls’ responses respectively during 98.4%, 78.4%, 86.76%, 47.9%, and 86.1% of the 40‐minute time period in testing, 20 minutes of baseline and 20 minutes after ingestion. In conclusion, we are looking at the sympathetic, parasympathetic, and enteric nervous systems synced temporally for applications with classification and further stratification of PASC based on the temporal dynamics of their autonomic nervous system mediated coordination from digestion. This shows that SARS‐CoV02 infection appears to have a significant effect on sympathetic and parasympathetic autonomic nervous system function and may be responsible for the disturbances noted in PASC. This work provides the framework and example of use for further applications in autonomic disorder physiological response exploration and furthermore can be expanded to other areas of neuromodulation.

PRE-OPERATIVE HEART RATE MONITORING AS A PREDICTOR OF POST SPINAL HYPOTENSION IN PATIENTS UNDERGOING LOWER SEGMENT CAESAREAN SECTION: AN OBSERVATIONAL STUDY

Background and Aims: Subarachnoid block (SAB) is widely used regional anaesthesia technique for the patients undergoing lower segment caesarean section (LSCS). It is associated with sympathetic autonomic nervous system blockade, as it blocks lumbosacral segment of the spinal cord. Haemodynamics is mainly controlled by autonomic nervous system, so this study was conducted to assess correlation between baseline heart rate and incidence of hypotension following subarachnoid block in parturients. Materials and Methods: After obtaining written and informed consent, 150 parturients aged &gt;18 years, with gestational age &gt;32 weeks were included in this prospective observational study. Parturients were randomly divided in two groups according to their baseline heart rate. Group I (n=75): parturients with HR ≥ 91 bpm and Group II (n=75): parturients with HR ≤ 90 bpm. All parturients were given inj. bupivacaine 0.5% Heavy 2 ml (10 mg) in SAB. Incidence of hypotension and other parameters, requirement of rescue drug were recorded. Results : In Group I (HR ≥ 91 bpm) incidence of hypotension (34 vs 21, P=0.0279), duration of hypotensive episode per parturient (2.15± 3.16 vs 1.02 ± 2.01, P=0.009) and requirement of rescue drug (mephentermine) per parturient (4.24±5.47 mg vs 2.56±4.54 mg, p=0.042) were signicantly higher as compared to Group II (HR ≤ 90 bpm). (p&lt;0.05) Conclusion: Parturients with HR ≥91 are at higher risk of developing hypotension after subarachnoid block and requirement of vasopressors is more as compared to those parturients with HR ≤90.

Relationship Between the Onset of Ménière's Disease and Sympathetic Hyperactivity.

ObjectiveThe pathogenesis of Ménière's disease is still largely unknown; however, it is known to be strongly associated with stress. Excessive stress can cause hyperactivity of the sympathetic autonomic nervous system. With the aim of understanding changes in sympathetic hyperactivity before and after Ménière's disease, we compared autonomic nervous function in patients in a stable phase of Ménière's disease and that in healthy adults. We also gathered data over about 10 years on autonomic nervous function immediately before a Ménière's attack.Study DesignProspective study.PatientsAutonomic nervous function was analyzed in 129 patients in a stable phase of Ménière's disease 31 healthy adult volunteers. In nine patients, autonomic nervous function was also measured immediately before and after treatment of a vertigo attack.Main Outcome MeasurePower spectrum analysis of heart rate variability (HRV) of EEG/ECG and an infrared electronic pupillometer were used. Sympathetic and parasympathetic nervous function was measured.ResultsThere were no statistically significant differences in autonomic nervous function determined by HRV and electronic pupillometry between patients in a stable phase of Ménière's disease and healthy adults. Sympathetic function as measured by electronic pupillometry parameters VD and T5 showed no difference between the affected and unaffected sides in the baseline data measured in the stable phase (VD: affected side is 31.02 ± 6.16 mm/sec, unaffected side is 29.25 ± 5.73 mm/sec; T5: affected side is 3.37 ± 0.43 msec, unaffected side is 3.25 ± 0.39 msec). In contrast, all nine patients whose HRV data had been obtained just before an attack showed marked suppression of the parasympathetic nervous system and activation of the sympathetic nervous system. Electronic pupillometry also revealed an overactivation of the sympathetic nervous system on the affected side, just before the attacks. Analysis of sequential changes after the onset of an attack revealed that overactivation on the affected side was reduced after treatment, and no difference between affected and unaffected sides was observed 3 days after treatment.ConclusionDetailed analysis of autonomic nervous function showed that immediately before an attack of Ménière's disease, the sympathetic nervous system on the affected side was strongly overactivated.

Review of Perioperative Music Medicine: Mechanisms of Pain and Stress Reduction Around Surgery.

Clinical-experimental considerations and an approach to understanding the autonomic basis of improved surgical outcomes using Perioperative Music Medicine (PMM) are reviewed. Combined surgical, psycho-physiological, and experimental perspectives on Music Medicine (MM) and its relationship to autonomic nervous system (ANS) function are discussed. Considerations are given to the inter-related perioperative effects of MM on ANS, pain, and underlying vagal and other neural circuits involved in emotional regulation and dysregulation. Many surgical procedures are associated with significant pain, which is routinely treated with post-operative opioid medications, which cause detrimental side effects and delay recovery. Surgical trauma shifts the sympathetic ANS to a sustained activation impairing physiological homeostasis and causing psychological stress, as well as metabolic and immune dysfunction that contribute to postoperative mortality and morbidity. In this article, we propose a plan to operationalize the study of mechanisms mediating the effects of MM in perioperative settings of orthopedic surgery. These studies will be critical for the implementation of PMM as a routine clinical practice and to determine the potential limitations of MM in specific cohorts of patients and how to improve the treatment.

Influence of Insulin Resistance and Obesity on the Autonomic Regulation of Rat Heart Rate under Conditions of Adequate and Limited Iodine Supply

Cardiovascular diseases remain a major medical problems in most countries around the world, causing significant economic disbenefit. An important pathogenetic mechanism of the influence of insulin resistance and hypothyroidism on the cardiovascular system is the alteration in the autonomic regulation of heart rhythm.&#x0D; Objective. The aim of the study was to evaluate the dynamics of heart rate variability (HRV) in rats with insulin resistance and obesity under the conditions of adequate and limited iodine supply.&#x0D; Materials and Methods. Studies were performed on 90 nonlinear rats pandomized by random sampling. The response of the autonomic nervous system (ANS) was studied using a computer program to analyze HRV “Poly-Spectrum.NET” with the additional module “Poly-Spectrum.NET/Veterinary”.&#x0D; Results. It was determined that the co-directed dynamics of geometric and statistical analysis of HRV and balance shift in the direction of the low-frequency component in spectrum analysis of the heart rate regarding control data were revealed in rats with isolated insulin resistance, obesity and combined endocrinopathy (insulin resistance and obesity under the conditions of limited iodine supply). &#x0D; Conclusion. The prevalence of sympathetic ANS activity under the conditions of insulin resistance and obesity can contribute to cardiac arrhythmias, the development of diabetic autonomic neuropathy and with a high probability to cause some cases of life-threatening arrhythmias (supraventricular and ventricular). Iodine deficiency contributes to the depletion of regulatory effects of ANS and limits the range of adaptive capabilities and resources of the organism.

Heart Rate Variability and Pain: A Systematic Review.

Background and Objective: Heart rate variability (HRV) as an index of the autonomic nervous system appears to be related to reactivity to experimental pain stimuli. HRV could better explain the contributions of sympathetic and parasympathetic activity response to nociceptive stimulation. The aim of this study was to systematically review and synthesize the current evidence on HRV in relation to the experience of pain in experimental tasks. Databases and Data Treatment: Studies indexed in the PubMed, PsycINFO, MEDLINE, WebOfScience, and Scopus databases were reviewed for eligibility. Studies on the autonomic response (i.e., HRV) to experimentally induced pain in healthy adults were included. Different methods of pain induction were considered (e.g., thermal, pressure, and electrical). Data were synthesized considering the association between HRV and both pain induction and subjective measures of pain. Results: Seventy-one studies were included. The results underline significant change in both the sympathetic and parasympathetic autonomic nervous systems during the painful stimulation independent of the pain induction method. The autonomic reaction to pain could be affected by several factors, such as sex, age, body mass index, breathing patterns, the intensity of the stimulation, and the affective state. Moreover, an association between the autonomic nervous system and the subjective experience of pain was found. Higher parasympathetic activity was associated with better self-regulation capacities and, accordingly, a higher pain inhibition capacity. Conclusions: HRV appears to be a helpful marker to evaluate nociceptive response in experimentally induced pain. Future studies are also needed in clinical samples to understand better the interindividual changes of autonomic response due to pain stimuli.

New Training Program for the New Requirements of Combat of Tactical Athletes

Actual theaters of operations are complex contexts where soldiers must face different situations, such as symmetrical, asymmetrical, or close quarter combat. The requirements of the actual battlefield are different to the traditional conditioning military training. This new changing scenario produces an activation of the innate fight or flight defense mechanisms with large activations of the anaerobic metabolic pathways and the sympathetic autonomic nervous system. In these scenarios, the anaerobic, aerobic, and strength demands are so specific and the time to improve all training demands in the units is limited. We propose a new training periodization for the military population based on the latest research into the psychophysiological response of soldiers in actual theaters of operations (actual military missions) and actual civilian models of training and periodization to develop a specific, easy, and reliable periodization model for actual tactical athletes. This training intervention was developed in order to improve operational training according to the demands of actual theaters of operations, based on recent research in military and civilian populations. We tried to conduct a proposal that is easy to apply, with minimal use of material different to what could be found in a military base and that could be implemented in a short period of time.