Sympathovagal Balance Research Articles

Cardiac Remodeling and Its Determinants in Anorexia Nervosa Adolescents: Impact of Weight Recovery.

Cardiovascular alterations in anorexia nervosa (AN) adolescents include bradycardia and decreased systolic blood pressure and left ventricular mass. However, their determinants remain poorly understood. We assessed the associations between morphological and functional left ventricular (LV) remodeling, autonomic control by heart rate variability (HRV) analysis, thyroid hormones and brain natriuretic peptide (BNP) levels in AN female adolescents without or with weight recovery (WR). Fifty-nine female adolescents including 16 AN patients without WR (mean age 13.9 years (10–16)), 10 AN patients with WR (15.7 years (12–18)) and 33 controls (14.1 years (10–18)) underwent night heart rate (HR) recording to measure HRV (and especially SD1/SD2, the ratio between instantaneous (SD1) and long-term (SD2) standard deviation of R-R intervals, reflecting sympatho-vagal balance), speckle tracking echocardiography to assess LV global longitudinal strain (GLS) and blood test for dosage of tri-iodothyronine (T3) hormone and NT-proBNP. Compared to controls, AN patients without WR presented with lower HR (55 ± 7 vs. 68 ± 6 bpm; p < 0.001), parasympathetic hyperactivity, and higher GLS (−19.2 ± 1.8 vs. −16.9 ± 2.8%; p = 0.009). These alterations were partly abolished in AN patients with WR. In a multivariate regression analysis, T3 was the main factor explaining the variance of SD1/SD2, a sympatho-vagal balance marker. NT-proBNP levels were not correlated with cardiac alterations. AN patients had parasympathetic hyperactivity linked with their rate of T3, and a higher GLS. These alterations were partly restored in AN patients with WR.

Association of choroidal blood flow with autonomic dysfunction in patients with normal tension glaucoma

There is increasing evidence that autonomic dysfunction is an important factor in the progression of glaucoma. Mechanism of the association between autonomic dysfunction and progression of glaucoma is poorly understood. Since blood circulation is basically regulated by the autonomic nervous system, autonomic dysfunction may contribute to unstable or fluctuating blood pressure. Therefore, It is hypothesized that autonomic dysfunction may contribute to impaired ocular blood flow and lead to glaucoma progression. However, no clinical study yet has evaluated the relationship between ocular blood flow and autonomic nervous function. We enrolled 152 open angle glaucoma patient. Ocular blood flow was assessed by measuring vessel density (VD) using optical coherence tomography angiography, and autonomic nervous function was evaluated with heart-rate variability (HRV) parameters. The low frequency/high frequency (LF/HF) ratio, which is one of the HRV parameters, quantified the degree of sympathovagal balance. This indicator could represent autonomic dysfunction. Higher LF/HF ratio was associated with reduction of the deep parapapillary VD (R = − 0.243, P = 0.003). Linear regression analysis showed a significant negative association between parapapillary choroidal VD and LF/HF ratio (β = − 0.249; 95% confidential interval = − 1.193 to − 0.249; P = 0.002) in multivariate analysis. We demonstarted the association between impaired ocular blood flow (parapapillary choroidal vessel density) and autonomic dysfunction (LF/HF ratio). This study could help understand the role of the autonomic dysfunction in pathophysiology of glaucoma progression.

Does cardiovascular autonomic dysfunction contribute to fatigue in myasthenia gravis?

Myasthenia gravis (MG) is an autoimmune disease characterized by fatigable muscle weakness. Despite full spontaneous or pharmacological remission some MG patients still complain of physical and mental fatigue. Fatigue has been related to autonomic dysregulation. The aim of this study was to assess autonomic responses in a group of MG patients in complete remission but complaining of persistent fatigue. Seventeen well-regulated but persistently fatigued MG patients and 17 individually matched controls underwent echocardiography assessing systolic and diastolic heart function. Beat to beat cardiovascular responses at rest and to 30o head-up tilt, tilt-back, and 2-min static handgrip contraction were recorded. Fatigued MG patients had a statistically significant higher resting HR than their matched controls (p=0.03). The difference in resting heart rate between MG patients not using acetylcholine esterase inhibitors (AChEi) and their matched controls was even more pronounced (p=0.007). The autonomic cardiovascular adjustments to head-up tilt, tilt-back and handgrip contraction were not statistically significant different between patients and controls. We found a higher resting heart rate in all well-regulated but fatigued MG patients compared with controls. The difference was more pronounced between patients not taking AChEi compared to their matched controls. This finding may reflect a disturbed resting sympathovagal balance and this might be a contributing factor to the fatigue symptoms.

Sympathovagal Balance Is a Strong Predictor of Post High-Volume Endurance Exercise Cardiac Arrhythmia.

Regular physical activity is important for cardiovascular health. However, high-volume endurance exercise has been associated with increased number of electrocardiogram (ECG) abnormalities, including disturbances in cardiac rhythm (arrhythmias) and abnormalities in ECG pattern. The aim of this study was to assess if heart rate variability (HRV) is associated with ECG abnormalities. Fifteen participants with previous cycling experience completed a 21-day high-volume endurance exercise cycle over 3,515 km. Participants wore a 5-lead Holter monitor for 24 h pre- and post-exercise, which was used to quantify ECG abnormalities and export sinus R-to-R intervals (NN) used to calculate HRV characteristics. As noise is prevalent in 24-h HRV recordings, both 24-h and heart rate collected during stable periods of time (i.e., deep sleep) were examined. Participants experienced significantly more arrhythmias post high-volume endurance exercise (median = 35) compared to pre (median = 12; p = 0.041). All 24-h and deep sleep HRV outcomes were not different pre-to-post high-volume endurance exercise (p > 0.05). Strong and significant associations with arrhythmia number post-exercise were found for total arrhythmia (total arrhythmia number pre-exercise, ρ = 0.79; age, ρ = 0.73), supraventricular arrhythmia (supraventricular arrhythmia number pre-exercise: ρ = 0.74; age: ρ = 0.66), and ventricular arrhythmia (age: ρ = 0.54). As a result, age and arrhythmia number pre-exercise were controlled for in hierarchical regression, which revealed that only deep sleep derived low frequency to high frequency (LF/HF) ratio post high-volume endurance exercise predicted post total arrhythmia number (B = 0.63, R2Δ = 34%, p = 0.013) and supraventricular arrhythmia number (B = 0.77, R2Δ = 69%, p < 0.001). In this study of recreationally active people, only deep sleep derived LF/HF ratio was associated with more total and supraventricular arrhythmias after high-volume endurance exercise. This finding suggests that measurement of sympathovagal balance during deep sleep might be useful to monitor arrhythmia risk after prolonged high-volume endurance exercise performance.

Dysautonomia in Parkinson's Disease: Impact of Glucocerebrosidase Gene Mutations on Cardiovascular Autonomic Control.

Evidence from clinical practice suggests that PD patients with the Glucocerebrosidase gene mutations (GBA-PD) are characterized by more severe dysautonomic symptoms than patients with idiopathic PD (iPD). Therefore, an accurate assessment of cardiovascular autonomic control (CAC) is necessary to clarify the role of GBA mutations in the pathophysiology of PD. We evaluated the CAC at rest and during orthostatic challenge of 15 iPD, 15 GBA-PD and 15 healthy controls (CTR). ECG and respiration were recorded in supine position and during active standing. The analysis of Heart Rate Variability (HRV) was performed on ECG recordings using two different approaches, linear spectral analysis and non-linear symbolic analysis. GBA-PD patients presented more frequently an akinetic-rigid phenotype and cognitive dysfunction than iPD patients. Both iPD and GBA-PD group were characterized by a lower spectral HRV than CTR group. At rest, the GBA-PD group was characterized by a lower parasympathetic modulation and a shift of the sympathovagal balance toward a sympathetic predominance compared to the CTR group. Moreover, the GBA-PD patients presented a lower HR increment and a lower or absent reduction of the vagal modulation in response to the active standing than iPD patients. Lastly, the cardiovascular autonomic dysfunction in PD patients was associated with longer disease duration, and with the occurrence of REM sleep behavior disorder and constipation. Our findings suggest a more severe impairment of the CAC in PD patients with GBA mutations. These results and further studies on the role of GBA mutations could allow a stratification based on cardiovascular risk in PD patients and the implementation of specific prevention programs.

Light exposure during sleep impairs cardiometabolic function

SignificanceAmbient nighttime light exposure is implicated as a risk factor for adverse health outcomes, including cardiometabolic disease. However, the effects of nighttime light exposure during sleep on cardiometabolic outcomes and the related mechanisms are unclear. This laboratory study shows that, in healthy adults, one night of moderate (100 lx) light exposure during sleep increases nighttime heart rate, decreases heart rate variability (higher sympathovagal balance), and increases next-morning insulin resistance when compared to sleep in a dimly lit (<3 lx) environment. Moreover, a positive relationship between higher sympathovagal balance and insulin levels suggests that sympathetic activation may play a role in the observed light-induced changes in insulin sensitivity.

TEST OF PHYSIOLOGICAL PERFORMANCE: RATIONALE AND FEASIBILITY

Rigorous clinical evaluation of the physiological performance is currently performed with complex and long procedures which need expensive technology and skilled operators. In a wide range of situations (frail patients, daily clinical practice, etc.), these approaches are difficult to be applied and simpler tests, with a lack of scientific background, are mandatory. To avoid these problems, we propose a test (test of physiological performance (TOPP)) to evaluate the physiological behavior of a subject, in a really easy and safe clinical setting, measuring only the heart rate. The subject is submitted to an active standing-up test and then two submaximal exercises (with a low power load) on a cycle-ergometer. The heart rate modifications due to each submaximal step are analyzed by exponential interpolation to calculate the ascending and descending time constants and evaluate the way each subject adapts his heart rate to work. The standard deviation of the RR for each stationary phase (warm-up, load, recovery) was calculated as an index of short-term variability. Then a standard Fourier analysis of the stationary periods of the standing-up procedures allows to quickly and easily evaluate the autonomic nervous activation. We tested the protocol on five healthy subjects to verify the feasibility and the acceptance of the procedure. The five subjects demonstrated a good tolerance of the entire procedure. The standing-up showed a behavior of the autonomic system consistent with the physiology (with an increase in sympathetic activation in the passage to standing position). The analysis of the two submaximal steps highlights how younger and trained subjects present lower heart rates (both in the ascending phase and in the recovery) with a quicker adaptation ability (smaller time constants) consistent with what is expected. The short-term variability of heart rate is greater in young and trained subjects, thus confirming how the sympatho-vagal balance, in these subjects, is more dynamic. The proposed test is well tolerated by the subjects and the results, albeit in a small cohort of healthy volunteers, are consistent with what is expected from physiology and is already present in the literature. Our work aims to be a proposal with a feasibility check of a method for evaluating performance. The work to be done for the clinical validation of the TOPP is still long, but we are aware that it can give important results and that the TOPP can become an effective tool for the assessment of the physiological performance even of fragile subjects.

Effects of transcutaneous electrical stimulation with the device “VEB” ® on the human body

Background. In 2015, a generator for electrotherapy and stimulation oh human nerve centers was created, called “VEB-1”®. Preliminary observation of volunteers revealed a modulating effect of a four-day course of electrical stimulation on the parameters of electroencephalogram, metabolism, as well as gas-discharge visualization (GDV). In this message, we present the results of the approbation of the device on an expanded contingent of volunteers with the use of additional research methods and a new modification of the device. Material and research methods. The object of observation were employees of the sanatorium “Moldova”, patients with chronic cholecystitis: 19 women 30-62 y and 19 men 25-63 y. In the morning registered HRV (“CardioLab+HRV”, “KhAI-Medica”, Kharkiv, UA), EEG (“NeuroCom Standard”, “KhAI-Medica”, Kharkiv, UA), kirlianogram by the method of GDV (“GDV Chamber”, “Biotechprogress”, SPb, RF), electroconductivity of skin in three pairs of points of acupuncture (“Medissa”), electrokinetic index of buccal epithelium ("Biotest", Kharkiv State University), as well as some endocrine, immune and metabolic parameters. After the initial testing, an transcutaneous electrical stimulation session was performed with a “VEB-1”® or a “VEB-2” devices. The next morning after completing the four-day course, retesting was performed. Results. Electrical stimulation causes a sympathotonic shift in the sympatho-vagal balance and an increase in PSD of delta-rhythm generating neurons combined with a decrease in PSD of beta- and theta-rhythm generating neurons. This is accompanied by increase in phagocytosis and favorable changes in immune, biochemical and biophysical parameters as well as increase in testosterone level in men only. The integral effects on the constellation of registered body parameters of both device modifications do not differ significantly. Conclusion. The "VEB" device exerts an adaptogenic effect on the body through transcutaneous electrical stimulation of neurons.

Sub Chronic effect of High fat consumption on heart rate variability and Nitric oxide (NO) in experimental rats: Protective role of Terminalia arjuna

Background: In the present study Albino wister rats displayed with increase in body weight, sympathetic activity and decreased parasympathetic function following a high fat consumption for a sub chronic period. Possible alterations of cardiac autonomic functions and molecular behaviour of nitric oxide were observed in the presence of ethanolic extract of Terminalia arjuna (ETA). Objectives: The study was aimed to find out impact of high fat diet on cardiac health in terms with HRV also through NO pathways alterations in experimental rats and to assess the cardio protective efficacy of Terminalia arjuna on hyperlipidemic rats. Methodology: Bark of Terminalia arjuna was extracted with 99% ethanol. Rats were grouped into four groups (n=6); Control as group 1 (20% fat); group 2 fed with (20% fat+ ETA 100 mg/kg/b w); group 3 fed with (30% fat) and group 4 fed with (30% fat + ETA 100mg/kg/b w). Body weight and percentage of body weight gain were calculated. Electrophysiological analysis(HRV and sympatho-vagal balance) were done. Biochemical assay was done to assess serum Nitric oxide levels(NO). ANOVA, Pearson’s correlation and multiple regression were done to analyze data. Results: Electrophysiological evaluation revealed altered sympatho-vagal balance in hyperlipidemic rats. Significant increase in sympathetic drive along with decrease in parasympathetic functions suggests cardiac autonomic dysfunction in rats fed with high fat. Subchronic supplementation of ethanolic extraction of Terminalia arjuna to hyperlipidemic rats showed significant beneficial effect on cardiac autonomic function. Significant negative correlation was observed between HRV and nitric oxide. Conclusion: Terminalia arjuna have exhibited its cardioprotective role in high fat fed rats by enhancing cardiac functions. Supplementation of ETA have shown important role in modulating autonomic control and in improving cardiovascular function. Probably polyphenolic compounds and flavonoids might have cardioprotective activity by rejuvenating action and free radical quenching actions.

“Study of Status of Sympathovagal Balance in Offsprings with Family History of Hypertension and in Those without It”

Background: Autonomic functions, sympathetic and vagal/ parasympathetic, are found to be deranged in hypertensive subjects. The derangement of autonomic functions in terms of sympatho-vagal imbalance has also been found in off-springs of hypertensive people. Method: Spectral analysis of heart rate variability (HRV) was recorded in 30 subjects of control group &amp; 30 subjects of case /study group( offsprings of hypertensive parents) before and after Hand Grip Test(HGT). Body mass index (BMI), basal heart rate (BHR), blood pressure (BP) was recorded at the outset. Spectral indices of HRV included Standard deviation of NN intervals (SDNN), total power (TP), normalized low frequency power (LFnu), normalized high frequency power (HFnu), ratio of low frequency power to high frequency power (LF-HF ratio), mean heart rate (mean RR), square root of the mean squared differences of successive normal to normal intervals (RMSSD) and the number of interval differences of successive NN intervals greater than 50 ms (NN50). Result: In study group SDNN &amp; LF/HF finding was significant which means there is a sympathetic dominant effect. Pre and Posttest HGT and HRV values were found to be significant when study and control groups were compared. This means changes occur in sympathetic variables before actual onset of hypertension. No correlation was seen as regards to HRV &amp; BMI. Conclusion: It can be concluded that offsprings of Hypertensive parents tend to have some degree of autonomic imbalance before the actual onset of essential hypertension.

Acupuncture Improves Heart Rate Variability, Oxidative Stress Level, Exercise Tolerance, and Quality of Life in Tracheal Collapse Dogs.

Among the respiratory disorders in dogs from small breeds, tracheal collapse is one of the most commonly found in clinical practice. Presently, acupuncture is widely used as an alternative treatment which was shown to bring about positive effects in the treatment of human respiratory diseases. The present study demonstrated the effect of acupuncture on tracheal collapse dogs. We hypothesized that acupuncture can help dogs suffering from tracheal collapse by improving various parameters including heart rate variability, serum biomarkers for oxidative stress, exercise performance, and quality of life. Twenty client-owned dogs from small breeds with tracheal collapse disease were enrolled. The study was divided into two 5-week periods. During the first period, the dogs received normal veterinary care but received no acupuncture treatment (NAC). After completing that period, all forms of treatment were withheld for one week before the beginning of the second period. In the second period, all dogs restarted normal veterinary care and underwent acupuncture treatment (AC) once a week for five consecutive weeks. Blood was collected at the beginning and end of each of the two periods for malondialdehyde (MDA) level measurement. Heart rate variability (HRV) was recorded at the 1st, 3rd and 5th weeks of both periods. Exercise tests were performed at the beginning and end of AC period and questionnaire interviews with the owners were accomplished at the end of each period. The results showed that acupuncture can alleviate clinical signs of tracheal collapse, reduce MDA level, and improve sympathovagal balance. We suggest that acupuncture treatment could be used as an adjunct treatment for canine tracheal collapse.

Heart Rate Variability and Sympathetic Activity Is Modulated by Very Low-Calorie Ketogenic Diet.

Obesity is characterized by an energy imbalance and by the accumulation of visceral adipose tissue. The energy balance is controlled by a complex set of balanced physiological systems that provide hunger and satiety signals to the brain and regulate the body’s ability to consume energy. The central nervous system controls the metabolic state, influencing the activity of other systems and receiving information from them. Heart rate variability (HRV) is the natural variability of the heart rate in response to several factors. HRV is related to the interaction between the SNS and the parasympathetic. In the light of this evidence, the aim of this study is to investigate the possible effects of the two different dietary regimens such as very low-calorie ketogenic diet (VLCKD) vs. low caloric diet (LCD), on the functions of the nervous system, with particular attention to the autonomous control of heart rate variability (HRV). A total of 26 obese subjects underwent diet therapy in order to reduce body weight; they were also randomly divided into two groups: the VLCKD group and the LCD group. Our results showed that in both groups, there is a reduction in heart rate as an indicator of sympathetic activity; we found a statistically significant variation only in the VLCKD group. Therefore, this study supports the notion that the sympathovagal balance can be modulated by a specific diet, but further studies are needed to clarify the molecular pathway undergoing this modulation.

Relationship of heart rate variability with serum zinc and magnesium in female rheumatoid arthritis patients

Background: Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease affecting multiple small symmetrical joints with extra-articular involvement. Altered blood mineral status is associated with the immune-inflammatory rheumatoid process. Reduced heart rate variability (HRV) is a predictor of sudden cardiac death in RA patients. So, the role of minerals for altered HRV needs investigation in RA. Objectives: To assess the relationship between HRV and serum zinc (Zn), magnesium and (Mg) levels in RA patients. Methods: This cross sectional study enrolled 60 female participants of 30-50 years of age. Among them 30 female RA patients were included in the study group and 30 age matched apparently healthy women constituted control group. Serum Zn, Mg levels were estimated by autoanalyzer and frequency domain parameters of HRV were recorded by a data acquisition device, Powerlab 8/35, AD Instruments, Australia followed by analysis with software, Lab chart. Statistical analyses were done by independent sample ‘t’ test and Pearson’s correlation coefficient test. Results: In this study, among frequency domain parameters of HRV, total power (TP), low frequency power(LF), high frequency power(HF), HF normalized unit(HF nu) were significantly lower (p&lt;0.05) and LF normalized unit (LF nu), LF/HF ratio were significantly higher (p&lt;0.05) in RA patients. In addition, significantly (p&lt;0.05) lower levels of serum Zn and Mg were found in RA patients as compared to controls. But on correlation analysis, the HF nu showed significant positive correlation and LF nu and LF/HF ratio demonstrated significant negative correlation (p&lt;0.05) with serum Mg only. Conclusion: Results of the present study revealed that low levels of serum Mg was correlated with reduced HRV in patients with RA. Moreover, low serum Mg was related to parasympathetic hypo and sympathetic hyperactivity as well as altered sympathovagal balance in RA. J Bngladesh Soc Physiol 2021;16(1): 111-117

Transcutaneous vagus nerve stimulation attenuates autoantibody-mediated cardiovagal dysfunction and inflammation in a rabbit model of postural tachycardia syndrome.

Previous studies demonstrated M2 muscarinic acetylcholine receptor-activating autoantibodies (M2R-AAb) were present in some patients with postural tachycardia syndrome (POTS). This study examines how these autoantibodies might contribute to the pathophysiology of POTS, and whether low-level tragus stimulation (LLTS) can ameliorate autoantibody-mediated autonomic dysregulation in the rabbit. Five New Zealand white rabbits were immunized with a M2R second extracellular loop peptide to produce cholinomimetic M2R-AAb. Tilt test and infusion studies were performed on conscious rabbits before immunization, 6weeks after immunization, and 8weeks after immunization with 2-week daily LLTS treatment. Each rabbit served as its own control. Compared to preimmune state, an enhanced heart rate increase and decreased parasympathetic activity upon tilting were observed in immunized rabbits. Furthermore, these rabbits demonstrated an attenuated heart rate-slowing response to infusion of the M2R orthosteric agonist arecaidine propargyl ester (APE), suggesting an inhibitory allosteric effect of M2R-AAb. There was also a significant increase in serum inflammatory cytokines in immunized rabbits. LLTS treatment suppressed the postural tachycardia, improved the sympathovagal balance with increased acetylcholine secretion, reduced the levels of inflammatory cytokines, and reversed the attenuated heart rate response to APE in immunized rabbits. No suppression of M2R-AAb expression by LLTS was found during this short-term study period. Receptor-modulating activity of M2R-AAb produced in immunized rabbits was confirmed with in vitro bioassay. Autoantibody inhibition of cholinergic ligand activity may be involved in the development of cardiovagal dysfunction and inflammation associated with POTS, both of which can be improved by vagal stimulation.

Effects of Physical Training on Heart Rate Variability in Children and Adolescents with Chronic Diseases: A Systematic Review and Meta-analysis.

This study analyzed the effects of physical training programs on heart rate variability, as a measure of sympathovagal balance, in children and adolescents with chronic diseases. Relevant articles were systematically searched in Pubmed, Science Direct, Web of Science, Scopus, Google Scholar and Embase scientific databases. We performed a meta-analysis using an inverse variance heterogeneity model. Effect size calculation was based on the standardized mean differences between pre- and post-intervention assessments, assuring at least a single-group repeated-measures model for each extracted group. Ten studies (252 participants) were included, seven in obese subjects, two in type-1 diabetes, and one in cerebral palsy. When time-domain variables were analyzed, exercise was found to moderately increase RMSSD (SMD=0.478; 95%CI: 0.227 to 0.729; p<0.001), SDNN (SMD=0.367; 95%CI: 0.139 to 0.595; p=0.002) and pNN50 (SMD=0.817; 95%CI: 0.139 to 0.595; p=0.002). As for frequency-domain variables, exercise presented a moderate increasing effect on HF (SMD=0.512; 95%CI: 0.240 to 0.783; p<0.001), a negligible effect for LF (SMD=0.077; 95%CI: -0.259 to 0.412; p<0.001) and a non-significant reduction for LF/HF (SMD=-0.519; 95%CI: -1.162 to 0.124; p=0.114). In conclusion, physical training programs are able to modulate heart rate variability in children and adolescents with chronic diseases, affecting mainly the time-domain variables.

Gender moderates the association between chronic academic stress with top-down and bottom-up attention

Research on the relationship between chronic stress and cognition is limited by a lack of concurrent measurement of state-anxiety, physiological arousal, and gender. For the first time, we assessed the impact of these factors on top-down/conscious (simple and choice reaction time) and bottom-up/reflexive (saccadic reaction time) measures of attention using CONVIRT virtual-reality cognitive tests. Participants (N = 163) completed measures of academic stress (effort-reward imbalance; ERI) and state-anxiety while heart-rate variability was recorded continuously throughout the experiment. Gender moderated the association between academic stress with the top-down measures (b = -0.002, t = -2.023, p = .045; b = -0.063, t = -3.080, p = .002) and higher academic stress was associated with poorer/slower reaction times only for male participants. For bottom-up attention, heart rate variability moderated the relationship between academic stress and saccadic reaction time (b = 0.092, t = 1.991, p = .048), and only female participants who were more stressed (i.e., ERI ≥ 1) and displayed stronger sympathetic dominance had slower reaction times. Our findings align with emerging evidence that chronic stress is related to hyperarousal in women and cognitive decrements in men. Our findings suggest that higher ERI and sympathetic dominance during cognitive testing was associated with poorer bottom-up attention in women, whereas for men, academic stress was related with poorer top-down attention irrespective of sympathovagal balance.

Normal bilirubinemia downregulates the power spectral density of the θ and Δ rhythm, instead upregulates the β rhythm and sympatho-vagal balance in adults humans

Background. Neonatal hyperbilirubinemia has been known to damage neural function. Our goal is to determine whether the neurotropic activity of normal bilirubinemia in adults is evident. Methods. The object of observation were 77 volunteers: 30 women and 47 men aged 49±13 (26 ÷ 76) years without clinical diagnosis. Testing was performed twice with an interval of 4 ÷ 10 days. We determined the plasma levels of the direct and free bilirubin, recorded EEG and HRV followed by analysis of correlations between parameters. Results. Significant downregulating effect of bilirubinemia was found on power spectrum density (PSD) theta and delta rhythm. In contrast, bilirubinemia has an upregulating effect on PSD beta rhythm and sympatho-vagal balance. The canonical correlation between direct &amp; free bilirubin levels, on the one hand, and EEG &amp; HRV parameters, on the other hand, is very strong: R=0,808; R2=0,654; χ2(80)=191; p&lt;10-6 (n=154). A similar canonical correlation was found between individual changes in parameters: R=0,753; R2=0,568; χ2(48)=83; p=0,001 (n=74). Conclusion. Even normal bilirubinemia has an downregulating effect on mainly theta and delta rhythm-generating nuclei and vagal tone, while upregulating effects on sympathetic tone and beta rhythm-generating nuclei.

TO STUDY AND CORRELATE THE EFFECT OF INTEGRATED APPROACH OF YOGA THERAPY ON FREQUENCY DOMAIN PARAMETERS AND POINCARE PLOT OF HEART RATE VARIABILITY AMONG PREDIABETICS

Introduction- Prediabetes is demarcated as an intervening stage amongst normal glucose tolerance and type 2 diabetes mellitus. The present study aimed toevaluate the effects ofthe Integrated approach of yoga therapyonlinear andnonlinear dynamics ofheart rate variability and correlate between a linear component that was frequency domainand nonlinear dynamics that was Poine care plotof heart rate variability. Method-The study was conducted in the Department of physiology, Rajasthan University of Health Sciences, Jaipur in association with RDBP Jaipuria hospital.Group A wasinvolved in the Integrated Approach of Yoga Therapy (IAYT)including Prayer, Omkar recitation, yoga postures, breathing techniques, Shavasana,counseling, and dietary modification and Group B was not involved in any yoga sessions. Result-In this study, an attempt has been made to assess specifically the nonlinear dynamics of HRV using Poincare plotafter the integrated approach of yoga therapyand compare it with that of the frequency domain of HRV assessed by linear measures.Thehigh-frequency power( 46.04±11.75 to 67.56± 13.06) and SD1 ( 28.75 ±3.15 to 45.66±2.15) were increased andlow frequency (LF) power ( 66.67±11.87 to 40.67± 13.9) and the SD2 ( 55.76± 1.15 to 44.88 ± 2.15) of the Poincare plot decreased compared to baseline insubjects whofollowedthe integrated approach of yoga therapy, Additionally, significant correlations were found between high frequency (HF) and SD1 (p &lt; 0.05), LF and SD2, (p &lt; 0.05), and LF/HF and SD2/SD1 (p &lt; 0.01). Conclusion-Integrated approach of yoga therapy practiced regularly can emerge as one of the important non-pharmacological tools for primary prevention of cardiovascular disease andrestoring sympathovagal balance. Poincare plot analysis is easier and more sensitive in evaluating the sympathovagal balance and observing the variation in heartbeats.

Assessing cardiovascular links to depression and anxiety in Australian professional drivers.

Train and truck drivers experience a myriad of unique occupational factors, which have been postulated to contribute to a high incidence of health conditions such as depression anxiety and cardiovascular disease amongst this population. The present study aimed to identify associations between heart rate variability and negative mood states such as depression and anxiety in a cohort of Australian truck and train drivers. 120 professional drivers (60 truck drivers, 60 train drivers) were recruited from the local community. Participants complete a battery of psychometric questionnaires to assess levels of negative mood states such as depression and anxiety. Participants then completed a baseline (resting) and active (driving) task while concurrent electrocardiography data was collected to obtain heart rate variability parameters. Anxiety and depression were found to be associated with increases in low frequency heart rate variability and sympathovagal balance, and a reduction in total power. The present study identified associations between negative mood states and heart rate variability parameters that are unique to this cohort.

Значение симпатовагального баланса как биофизического маркера преэклампсии

Преэклампсия (ПЭ) является одним из серьезных осложнений беременности, которое приводит к синдрому полиорганной недостаточности. Целью исследования было изучение взаимосвязи симпатовагального баланса и типа центральной материнской гемодинамики у беременных с ПЭ. Материалы и методы. Было проведено изучение типа центральной материнской гемодинамики и вариабельности сердечного ритма у 102 пациенток в 32–37 недель беременности. 30 из них были с физиологическим течением процесса гестации и составили группу I (контроля). Во II группе под наблюдением находилось 40 беременных с ПЭ легкой и средней степени. К III группе были отнесены 32 пациентки с ПЭ тяжелой степени. Результаты. Показатели вариабельности сердечного ритма матери отражали гиперсимпатикотонию на фоне ПЭ. Полученные данные подтверждали известную гипердинамическую модель легкой и среднетяжелой ПЭ. Сохранность гестационной гиперволемии на фоне повышенного периферического сопротивления сосудов приводила к увеличению сердечного выброса. Переход к гиповолемии и низкому сердечному выбросу отражал гиподинамическую гемоциркуляцию на фоне тяжелой ПЭ. Повышение симпатовагального баланса было признаком вазоконстрикции и гипоперфузии. Это было подтверждено наличием сильной корреляции между симпатовагальным балансом и общим периферическим сопротивлением сосудов (R = 0,70; р &lt; 0,05), симпатовагальным балансом и сердечным индексом (R = –0,63; р &lt; 0,05 ). Вывод. Повышение симпатовагального баланса более 2,0 было биофизическим маркером ПЭ.