Autonomic Nervous System Imbalance Research Articles

Heart rate variability and cognitive functions in adolescents with complex congenital heart disease.

Heart Rate Variability (HRV) originates from the interplay between parasympathetic/sympathetic inputs to the heart, thus serving as an indicator of Autonomic Nervous System regulation. Prior research indicates that decreased HRV, marked by reduced autonomic balance, is related to poorer cognitive performance. While the population with congenital heart disease (CHD) show changes in HRV linked with the heart defect, the association between HRV and cognitive functions in CHD remains unexplored. 46 adolescents with CHD who went through infant open-heart surgery and 64 healthy controls (50.9% males, 12.8 ± 1.4 years) underwent neurodevelopmental testing and photoplethysmograph acquisition. Group differences and associations with cognitive functions were analysed with linear regression. P values were FDR-corrected. Adolescents with CHD showed lower HRV (quantified by high-frequency power) compared to controls (p < 0.001). Lower HRV was correlated with worse executive function (β = 0.24, p = 0.044) and lower IQ (β = 0.26, p = 0.010) in the whole sample and with lower IQ (β = 0.35, p = 0.014) in the CHD group. These associations were robust to confounders, including age, sex, and socioeconomic status. Our findings demonstrate an association between HRV and cognitive functions in adolescents with complex CHD. Early detection of alterations in HRV/autonomic regulation may help to identify children with CHD at risk for cognitive impairments. Adolescents with congenital heart disease (CHD) showed lower heart rate variability (HRV), indicating an imbalanced autonomic nervous system. Lower HRV was associated with lower IQ and executive function (EF) in the whole sample. The association between HRV and IQ was significantly stronger in CHD than in healthy controls. This study provides the first evidence of a link between altered HRV and cognitive impairments in the CHD population. Neurodevelopmental impairments seen in adolescents with CHD could be linked to their altered cardiac autonomic nervous activity, marked by low HRV.

Phenotypes of COVID-19-associated dysautonomia in patients requiring veno-venous extracorporeal membrane oxygenation

Background. Patients with novel coronavirus infection (COVID-19) receiving veno-venous extracorporeal membrane oxygenation (VV-ECMO) are typically prone to hemodynamic disorders of various severity. Tachycardia, increased cardiac output, or arterial hypotension affect the effectiveness of VV-ECMO. One of the possible causes of hemodynamic disorders leading to ineffective VV-ECMO may be dysautonomia (DA), which refers to an imbalance of sympathetic and parasympathetic divisions of the autonomic nervous system (ANS). The development of DA in various critical conditions was described previously. Dysautonomia also develops in COVID-19 (COVID-19-associated DA), but it was studied only in stable non-ICU patients. The presented study focuses on COVID-19-associated DA in critical COVID-19 patients requiring VV-ECMO support. The study was aimed at determining COVID-19-associated DA phenotypes, their impact on VV-ECMO effectiveness and disease outcomes. Materials and methods. The study included 20 patients: 12 (60%) females, 8 (40%) males. The patients had an average age of 55 years. All the patients underwent 24-hour Holter monitoring with spectral analysis of heart rate variability (HRV) assessing low-frequency component of the spectrum (LF), the high-frequency component of the spectrum (HF), the LF/HF ratio on days 1, 3, and 5 of VV-ECMO. Diagnostic criteria for COVID-19-associated DA was a decrease in LF/HF 2.28 or an increase in LF/HF 6.94. The diagnostic criteria of predominant tone of sympathetic nervous system (sympathetic tone) was an increase in LF/HF 6.94, while a decrease in LF/HF 2.28 indicated predominant parasympathetic tone. Low sympathetic tone was determined by a decrease in LF 15%, and an increase in LF 40%. Low parasympathetic tone was determined by a decrease in HF 15%, and an increase in HF 25%. The criteria used were based on the results of previous studies. The following parameters were registered in the study population: VV-ECMO weaning, duration of respiratory and VV-ECMO support, length of stay in the intensive care unit (ICU) and in hospital, and disease outcomes. Results. COVID-19-associated DA was diagnosed in all the patients. LF/HF median value was 0.1. HRV spectrum parameters changed significantly over time: on day 5 of VV-ECMO support LF and HF values significantly decreased. The patients were divided into three groups according to the DA phenotype: group 1 (n = 4 [20%]) with normal sympathetic tone and high parasympathetic tone (nShP phenotype); group 2 (n = 14 [70%]) with low sympathetic tone and high parasympathetic tone (lShP phenotype); group 3 (n = 2 [10%]) with low sympathetic tone and normal parasympathetic tone (lSnP phenotype). The latter group was excluded from further statistical analysis due to the small sample size. In group 2, the mean HR was significantly higher compared with group 1. In group 1, VV-ECMO weaning was successful in 50% of cases, whereas in group 2 it was successful in 7.2% (p = 0.04). Conclusions. To determine a dysautonomia phenotype, it is necessary to continuously monitor DA status in COVID-19 patients during VV-ECMO. Tachycardia in COVID-19 patients during VV-ECMO does not exclude the ANS imbalance with a significant predominance of parasympathetic tone over the sympathetic tone. It is this COVID-19-associated DA phenotype that is significantly associated with the unfavorable outcomes.

Phenotypes of COVID-19-associated dysautonomia in patients requiring veno-venous extracorporeal membrane oxygenation

Background. Patients with novel coronavirus infection (COVID-19) receiving veno-venous extracorporeal membrane oxygenation (VV-ECMO) are typically prone to hemodynamic disorders of various severity. Tachycardia, increased cardiac output, or arterial hypotension affect the effectiveness of VV-ECMO. One of the possible causes of hemodynamic disorders leading to ineffective VV-ECMO may be dysautonomia (DA), which refers to an imbalance of sympathetic and parasympathetic divisions of the autonomic nervous system (ANS). The development of DA in various critical conditions was described previously. Dysautonomia also develops in COVID-19 (COVID-19-associated DA), but it was studied only in stable non-ICU patients. The presented study focuses on COVID-19-associated DA in critical COVID-19 patients requiring VV-ECMO support. The study was aimed at determining COVID-19-associated DA phenotypes, their impact on VV-ECMO effectiveness and disease outcomes. Materials and methods. The study included 20 patients: 12 (60%) females, 8 (40%) males. The patients had an average age of 55 years. All the patients underwent 24-hour Holter monitoring with spectral analysis of heart rate variability (HRV) assessing low-frequency component of the spectrum (LF), the high-frequency component of the spectrum (HF), the LF/HF ratio on days 1, 3, and 5 of VV-ECMO. Diagnostic criteria for COVID-19-associated DA was a decrease in LF/HF 2.28 or an increase in LF/HF 6.94. The diagnostic criteria of predominant tone of sympathetic nervous system (sympathetic tone) was an increase in LF/HF 6.94, while a decrease in LF/HF 2.28 indicated predominant parasympathetic tone. Low sympathetic tone was determined by a decrease in LF 15%, and an increase in LF 40%. Low parasympathetic tone was determined by a decrease in HF 15%, and an increase in HF 25%. The criteria used were based on the results of previous studies. The following parameters were registered in the study population: VV-ECMO weaning, duration of respiratory and VV-ECMO support, length of stay in the intensive care unit (ICU) and in hospital, and disease outcomes. Results. COVID-19-associated DA was diagnosed in all the patients. LF/HF median value was 0.1. HRV spectrum parameters changed significantly over time: on day 5 of VV-ECMO support LF and HF values significantly decreased. The patients were divided into three groups according to the DA phenotype: group 1 (n = 4 [20%]) with normal sympathetic tone and high parasympathetic tone (nShP phenotype); group 2 (n = 14 [70%]) with low sympathetic tone and high parasympathetic tone (lShP phenotype); group 3 (n = 2 [10%]) with low sympathetic tone and normal parasympathetic tone (lSnP phenotype). The latter group was excluded from further statistical analysis due to the small sample size. In group 2, the mean HR was significantly higher compared with group 1. In group 1, VV-ECMO weaning was successful in 50% of cases, whereas in group 2 it was successful in 7.2% (p = 0.04). Conclusions. To determine a dysautonomia phenotype, it is necessary to continuously monitor DA status in COVID-19 patients during VV-ECMO. Tachycardia in COVID-19 patients during VV-ECMO does not exclude the ANS imbalance with a significant predominance of parasympathetic tone over the sympathetic tone. It is this COVID-19-associated DA phenotype that is significantly associated with the unfavorable outcomes.

State- and frequency-dependence in autonomic rebalance mediated by intradermal auricular electroacupuncture stimulation

BackgroundVagus nerve stimulation (VNS) improves diseases such as refractory epilepsy and treatment-resistant depression, likely by rebalancing the autonomic nervous system (ANS). Intradermal auricular electro-acupuncture stimulation (iaES) produces similar effects. The aim of this study was to determine the effects of different iaES frequencies on the parasympathetic and sympathetic divisions in different states of ANS imbalance.MethodsWe measured heart rate variability (HRV) and heart rate (HR) of non-modeled (normal) rats with the treatment of various frequencies to determine the optimal iaES frequency. The optimized iaES frequency was then applied to ANS imbalance model rats to elucidate its effects.Results30 Hz and 100 Hz iaES clearly affected HRV and HR in normal rats. 30 Hz iaES increased HRV, and decreased HR. 100 Hz iaES decreased HRV, and increased HR. In sympathetic excited state rats, 30 Hz iaES increased HRV. 100 Hz iaES increased HRV, and decreased HR. In parasympathetic excited state rats, 30 Hz and 100 Hz iaES decreased HRV. In sympathetic inhibited state rats, 30 Hz iaES decreased HRV, while 100 Hz iaES decreased HR. In parasympathetic inhibited rats, 30 Hz iaES decreased HR and 100 Hz iaES increased HRV.Conclusion30 Hz and 100 Hz iaES contribute to ANS rebalance by increasing vagal and sympathetic activity with different amplifications. The 30 Hz iaES exhibited positive effects in all the imbalanced states. 100 Hz iaES suppressed the sympathetic arm in sympathetic excitation and sympathetic/parasympathetic inhibition and suppressed the vagal arm and promoted the sympathetic arm in parasympathetic excitation and normal states.

Systemic and ocular pressure changes following sympathetic activation in yoga practitioners - A comparative study

Introduction and Aim: Blood Pressure (BP), Intraocular Pressure (IOP) and Ocular Perfusion Pressure (OPP) are precursor parameters that lead to development of glaucoma. Under conditions of stress, either physical or psychological origin, there is disturbance of autonomic regulation. This causes increased activation of the sympathetic nervous system which might influence BP and ocular pressures. An altered autonomic balance towards lower sympathetic drive is observed in subjects practicing yoga, but it is not clear whether this adaptation also influences ocular pressures. Our study attempted to analyze variations in BP, IOP and OPP following sympathetic activation in yogic practitioners and non-practitioners of yoga. Materials and Methods: One hundred and ten subjects aged 18 - 25 years were recruited and categorised into yoga and non-yoga group. Basal BP was recorded using a sphygmomanometer and IOP was recorded using a rebound tonometer. Isometric hand grip (IHG) and Cold pressor test (CPT) were administered one at a time. IOP and BP were recorded immediately following these sympathetic activation tests. Mean arterial pressure and OPP was calculated using standard formula. Results: Significant increase in the values of pulse, BP, IOP and OPP following sympathetic activation were observed in the non-yoga group which was not noted in the yoga group. Elevation in systemic and ocular pressures following sympathetic activation was less in yoga practitioners. This adrenergic response was greater in the non-yoga group. Conclusion: Regular yoga practice maintains adequate perfusion of ocular tissues by autoregulation. Hence yoga can be recommended as a complementary health approach for the autonomic nervous system imbalance.

Long-COVID-19 autonomic dysfunction: An integrated view in the framework of inflammaging

The recently identified syndrome known as Long COVID (LC) is characterized by a constellation of debilitating conditions that impair both physical and cognitive functions, thus reducing the quality of life and increasing the risk of developing the most common age-related diseases. These conditions are linked to the presence of symptoms of autonomic dysfunction, in association with low cortisol levels, suggestive of reduced hypothalamic-pituitary-adrenal (HPA) axis activity, and with increased pro-inflammatory condition. Alterations of dopamine and serotonin neurotransmitter levels were also recently observed in LC. Interestingly, at least some of the proposed mechanisms of LC development overlap with mechanisms of Autonomic Nervous System (ANS) imbalance, previously detailed in the framework of the aging process. ANS imbalance is characterized by a proinflammatory sympathetic overdrive, and a concomitant decreased anti-inflammatory vagal parasympathetic activity, associated with reduced anti-inflammatory effects of the HPA axis and cholinergic anti-inflammatory pathway (CAP). These neuro-immune-endocrine system imbalanced activities fuel the vicious circle of chronic inflammation, i.e. inflammaging. Here, we refine our original hypothesis that ANS dysfunction fuels inflammaging and propose that biomarkers of ANS imbalance could also be considered biomarkers of inflammaging, recognized as the main risk factor for developing age-related diseases and the sequelae of viral infections, i.e. LC.

Magnetic vagus nerve stimulation alleviates myocardial ischemia-reperfusion injury by the inhibition of pyroptosis through the M2AChR/OGDHL/ROS axis in rats.

Myocardial ischemia-reperfusion (I/R) injury is accompanied by an imbalance in the cardiac autonomic nervous system, characterized by over-activated sympathetic tone and reduced vagal nerve activity. In our preceding study, we pioneered the development of the magnetic vagus nerve stimulation (mVNS) system. This system showcased precise vagus nerve stimulation, demonstrating remarkable effectiveness and safety in treating myocardial infarction. However, it remains uncertain whether mVNS can mitigate myocardial I/R injury and its specific underlying mechanisms. In this study, we utilized a rat model of myocardial I/R injury to delve into the therapeutic potential of mVNS against this type of injury. Our findings revealed that mVNS treatment led to a reduction in myocardial infarct size, a decrease in ventricular fibrillation (VF) incidence and a curbing of inflammatory cytokine release. Mechanistically, mVNS demonstrated beneficial effects on myocardial I/R injury by inhibiting NLRP3-mediated pyroptosis through the M2AChR/OGDHL/ROS axis. Collectively, these outcomes highlight the promising potential of mVNS as a treatment strategy for myocardial I/R injury.

Brain-Splenic Immune System Interactions in Hypertension: Cellular and Molecular Mechanisms.

Hypertension represents a major worldwide cause of death and disability, and it is becoming increasingly clear that available therapies are not sufficient to reduce the risk of major cardiovascular events. Various mechanisms contribute to blood pressure increase: neurohormonal activation, autonomic nervous system imbalance, and immune activation. Of note, the brain is an important regulator of blood pressure levels; it recognizes the peripheral perturbation and organizes a reflex response by modulating immune system and hormonal release to attempt at restoring the homeostasis. The connection between the brain and peripheral organs is mediated by the autonomic nervous system, which also modulates immune and inflammatory responses. Interestingly, an increased autonomic nervous system activity has been correlated with an altered immune response in cardiovascular diseases. The spleen is the largest immune organ exerting a potent influence on the cardiovascular system during disease and is characterized by a dense noradrenergic innervation. Taken together, these aspects led to hypothesize a key role of neuroimmune mechanisms in the onset and progression of hypertension. This review discusses how the nervous and splenic immune systems interact and how the mechanisms underlying the neuroimmune cross talk influence the disease progression.

Impact of regular cold exposure on electrical skin resistance in patients with joint degenerative diseases.

Common features in chronic inflammatory disease patients (CIDP) are inflammation, mental stress (MS), and autonomic nervous system imbalance. Whole-body cryotherapy (WBC) exposure and regular physical exercise are known to regulate these features. In this study, we assessed the impact of regular physical exercise and the use of WBC exposure in CIDP on the level of electrical skin resistance (SR) to evaluate the skin sympathetic nervous activity and and estimate MS levels. SR was evaluated before and after a 10-day-period of daily physical exercise preceded or not by WBC (3 min at -110°C) in two groups of 134 CIDP (WBC vs. non-WBC groups). At baseline, the number of severe MS patients was similar in both groups. However, after the training period, the number of severe MS patients significantly decreased in the WBC group, only. An increase in SR (a decrease in stress level) was noted in the WBC group only, and such increase was higher in men than in women and in patients younger than 60 versus patients older than 60 years old. The use of daily WBC combined with physical exercise induced physiological adaptations and lowered the sympathetic nervous activity that may reflect a reduced level of MS in CIDP. These adaptations seem to depend on gender and age.

Sound stimulation using the individual's heart rate to improve the stability and homeostasis of the autonomic nervous system.

In this study, we explain the role of enhancing the stability and homeostasis of the autonomic nervous system (ANS) by proposing the average heart rate sound resonance (aHRSR), a sound stimulation to prevent imbalance of ANS due to dynamic movement. The effect of aHRSR on ANS was analyzed through the time and frequency domain of heart rate variability (HRV) using the photoplethysmogram data (PPG) of 22 participants (DUIRB-202109-12). When the subjects performed dynamic movements that could cause changes in the ANS, HRV indicators using PPG data for 5 min before and after the movements were analyzed according to the presence or absence of aHRSR. The standard deviation of the NN intervals (SDNN), the square root of the mean squared differences of the NN intervals (RMSSD), low-frequency band (LF), and high-frequency band (HF), which represent sympathetic and parasympathetic nerve activity, were used as indicators, where SNDD and LF represent total ANS and sympathetic activity, while RMSSD and HF represent parasympathetic activity. As the effects of aHRSR on dynamic movement, the recovery time of RR interval was advanced by about 15 s, SDNN increased from ([44.16 ± 13.11] to [47.85 ± 15.16]) ms, and RMSSD increased from ([23.73 ± 9.95] to [31.89 ± 12.48]) ms (p < 0.05), increasing the stability of the ANS and reducing instability. The effect of homeostasis of the ANS according to aHRSR is also shown in reducing the change rate of LF from (-13.83 to -8.83) %, and the rate of change of HF from (10.59 to 3.27) %. These results suggest that aHRSR can affect the cardiovascular system by assisting physiological movements that occur during dynamic movement.

Altered Heart Rate Variability During Rest in Schizophrenia: A State Marker.

Autonomic nervous system (ANS) imbalance has been reported in a number of psychiatric disorders such as depression, schizophrenia, panic disorder, etc. Autonomic dysfunction in schizophrenia has been associated with the symptoms and manifestation of psychosis. Heart rate variability (HRV) as a tool has been widely used to assess ANS activity and the effect of disease on the sympathovagal balance. Therefore, in the present study, HRV derived from electrocardiogram (ECG) lead II at rest was investigated in order to understand the changes in frequency domain measures in patients with schizophrenia and their first-degree relatives compared to healthy controls. Twenty-five patients with schizophrenia, 24 first-degree relatives of patients, and 24 healthy controls (Diagnostic and Statistical Manual of Mental Disorders (DSM)-5; 18-45 years) were included in the study. HRV of the subjects was measured after five minutes of rest. ECG lead II was recorded for five minutes and HRV was analysed in the frequency domain: low frequency (LF), high frequency (HF), total power, and LF/HF ratio. HRV parameters and heart rate were statistically analysed for group comparisons using general linear model multivariate analysis. Patients had significantly higher minimum heart rate and lower HF (normalized units (nu)) compared to their first-degree relatives. A trend was observed in HF (nu) with the lowest in patients followed by healthy controls and first-degree relatives and LF/HF ratio was the highest in patients followed by healthy controls and first-degree relatives, although not statistically significant. No significant difference was found between first-degree relatives and healthy controls. The alteration of HRV in schizophrenia could be attributed to reduction in vagal tone and sympathetic dominance, which in turn could serve as state markers of schizophrenia.

A History of Suicide Attempt Is Associated with Increased Sympathetic Activation in Bipolar Disorder.

Suicide risk in bipolar disorder (BD) is estimated to be up to 20 times higher than in the general population. While there is a large body of evidence suggesting that increased sympathetic activation is associated with disease and death, there is a paucity of research on the role of autonomic nervous system (ANS) dysfunction in patients with BD who have attempted suicide. Fifty-three participants with BD used a wearable device to assess the association between history of suicide attempt, current suicidal ideation, and ANS dysfunction, including measures of heart rate variability (HRV) and respiratory rate. Data were analyzed in a series of unadjusted and adjusted bivariate models of association controlling for relevant variables. A history of suicide attempts was significantly associated with an increase in respiratory rate (p < 0.01). These results remained significant after adjusting for age, BMI, and current mood state. There was no association between current suicidal ideation and heart rate or respiratory rate. In the frequency domain, HRV parameters suggest reduced parasympathetic (i.e., vagal) activity in participants with a history of suicide attempts and in those with current suicidality, suggesting changes in sympathicovagal balance in BD. Our results suggest that changes in the ANS in patients with BD and a history of suicide attempt are not restricted to pure vagally mediated HRV parameters, but rather signal a general ANS dysregulation. This ANS imbalance may be contributing to illness burden and cardiovascular disease. Further research on the relationship between ANS and suicidality in BD is needed.

Hypertensive Heart Failure.

Despite overwhelming epidemiological evidence, the contribution of hypertension (HTN) to heart failure (HF) development has been undermined in current clinical practice. This is because approximately half of HF patients have been labeled as suffering from HF with preserved left ventricular (LV) ejection fraction (EF) (HFpEF), with HTN, obesity, and diabetes mellitus (DM) being considered virtually equally responsible for its development. However, this suggestion is obviously inaccurate, since HTN is by far the most frequent and devastating morbidity present in HFpEF. Further, HF development in obesity or DM is rare in the absence of HTN or coronary artery disease (CAD), whereas HTN often causes HF per se. Finally, unlike HTN, for most major comorbidities present in HFpEF, including anemia, chronic kidney disease, pulmonary disease, DM, atrial fibrillation, sleep apnea, and depression, it is unknown whether they precede HF or result from it. The purpose of this paper is to provide a contemporary overview on hypertensive HF, with a special emphasis on its inflammatory nature and association with autonomic nervous system (ANS) imbalance, since both are of pathophysiologic and therapeutic interest.

Sympathetic circuits regulating hepatic glucose metabolism: where we stand.

The prevalence of metabolic disorders, including type 2 diabetes mellitus, continues to increase worldwide. Although newer and more advanced therapies are available, current treatments are still inadequate and the search for solutions remains. The regulation of energy homeostasis, including glucose metabolism, involves an exchange of information between the nervous systems and peripheral organs and tissues; therefore, developing treatments to alter central and/or peripheral neural pathways could be an alternative solution to modulate whole body metabolism. Liver glucose production and storage are major mechanisms controlling glycemia, and the autonomic nervous system plays an important role in the regulation of hepatic functions. Autonomic nervous system imbalance contributes to excessive hepatic glucose production and thus to the development and progression of type 2 diabetes mellitus. At cellular levels, change in neuronal activity is one of the underlying mechanisms of autonomic imbalance; therefore, modulation of the excitability of neurons involved in autonomic outflow governance has the potential to improve glycemic status. Tissue-specific subsets of preautonomic neurons differentially control autonomic outflow; therefore, detailed information about neural circuits and properties of liver-related neurons is necessary for the development of strategies to regulate liver functions via the autonomic nerves. This review provides an overview of our current understanding of the hypothalamus-ventral brainstem-liver pathway involved in the sympathetic regulation of the liver, outlines strategies to identify organ-related neurons, and summarizes neuronal plasticity during diabetic conditions with a particular focus on liver-related neurons in the paraventricular nucleus.

Transcutaneous auricular vagus nerve stimulation as a potential novel treatment for polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a common endocrine disorder in women of childbearing age. The etiology of PCOS is multifactorial, and current treatments for PCOS are far from satisfactory. Recently, an imbalanced autonomic nervous system (ANS) with sympathetic hyperactivity and reduced parasympathetic nerve activity (vagal tone) has aroused increasing attention in the pathogenesis of PCOS. In this paper, we review an innovative therapy for the treatment of PCOS and related co-morbidities by targeting parasympathetic modulation based on non-invasive transcutaneous auricular vagal nerve stimulation (ta-VNS). In this work, we present the role of the ANS in the development of PCOS and describe a large number of experimental and clinical reports that support the favorable effects of VNS/ta-VNS in treating a variety of symptoms, including obesity, insulin resistance, type 2 diabetes mellitus, inflammation, microbiome dysregulation, cardiovascular disease, and depression, all of which are also commonly present in PCOS patients. We propose a model focusing on ta-VNS that may treat PCOS by (1) regulating energy metabolism via bidirectional vagal signaling; (2) reversing insulin resistance via its antidiabetic effect; (3) activating anti-inflammatory pathways; (4) restoring homeostasis of the microbiota-gut-brain axis; (5) restoring the sympatho-vagal balance to improve CVD outcomes; (6) and modulating mental disorders. ta-VNS is a safe clinical procedure and it might be a promising new treatment approach for PCOS, or at least a supplementary treatment for current therapeutics.

The Influence of Sleep Quality on the Body Composition, Selective Attention, and Autonomic Nervous System Activity in Healthy Individuals

Objective: This study aimed to investigate whether the sleep quality is associated with body composition, selective attention, and autonomic nervous system (ANS) activity in healthy young individuals.Methods: This cross-sectional study was conducted using the Korean version of Pittsburgh Sleep Quality Index (PSQI-K). Sixteen healthy volunteers aged 20–26 years participated in this study. The PSQI-K was used to evaluate sleep quality, and they were divided into good and poor sleeper groups by PSQI-K. Body composition, and both reaction time and error number for discriminative reaction task indicating the selective attention, and ANS activity were measured and it compared according to sleep quality. Additionally, the correlation between sleep quality and ANS activity was analyzed.Results: There were no significant differences in the body composition, reaction time and error number between good and poor sleeper groups. In the ANS activity, the poor sleeper group only showed the lower HF value than the good sleeper group in resting state (p=0.023). Whereas, the amount of change (reaction task state – resting state) in mean HR (p=0.005), HF (p=0.039), and LF/HF ratio (p=0.023) were significantly different between the groups. Additionally, a negative correlation was observed between PSQI-K and HF (p=0.005), while a positive correlation was confirmed between PSQIK and LF/HF ratio (p=0.012).Conclusion: These findings indicate that even healthy individuals may have physiological problems such as ANS imbalance if the sleep quality is poor.

PS-B10-5: EFFECTS OF CHRONIC ACETYLCHOLINESTERASE INHIBITION WITH PYRIDOSTIGMINE ON CARDIOVASCULAR SYSTEM AND AUTONOMIC BALANCE IN SPONTANEOUSLY HYPERTENSIVE RATS

Objective: The imbalance in autonomic nervous system, characterized by increased sympathetic and attenuated parasympathetic activity, plays an important role in the pathogenesis of hypertension. The spontaneously hypertensive rats (SHR) which are one of the most studied animal models of essential hypertension, are characterized by autonomic nervous system imbalance. Our study was aimed to determine the effect of chronic inhibition of acetylcholinesterase with pyridostigmine on cardiovascular parameters and sympatho-vagal balance in SHR and Wistar-Kyoto (WKY) rats. Design and method: Adult male SHR and WKY rats were treated with pyridostigmine (25 mg/kg/day) in drinking solution for 2 weeks. The rats were implanted with telemetric transducers to measure blood pressure (BP) and heart rate (HR). Autonomic balance was evaluated by power spectral analysis of systolic blood pressure variability (SBPV) and heart rate variability (HRV). Sympatho-vagal balance was also evaluated pharmacologically by administration of methylatropine (antagonist of muscarinic acetylcholine receptors) and propranolol (antagonist of beta-adrenergic receptors) in a separate set of rats. Results: SHR have elevated BP, increased vascular sympathetic activity (low frequency component of SBPV), and reduced HRV compared to WKY. Pyridostigmine significantly reduced HR in rats of both strains (during both dark and light phase) and BP during the dark (active) phase compared to untreated controls. Acetylcholinesterase activity in plasma was significantly reduced by pyridostigmine treatment in both strains (SHR 53 ± 3%, WKY 46 ± 3%). Sympatho-vagal balance examination revealed reduced cardiac vagal tone in SHR as evidenced by blunted HR response to the muscarinic receptor blocker methylatropine and increased cardiac sympathetic tone as evidenced by elevated HR response to the beta-blocker propranolol. Pyridostigmine treatment increased cardiac vagal tone and decreased cardiac sympathetic tone in SHR to the levels of untreated WKY. Moreover, pyridostigmine increased HRV and reduced low frequency component of SBPV in SHR indicating the restoration of autonomic balance. The reduction of sympathetic tone in pyridostigmine-treated rats was also evident from the reduction of plasma levels of noradrenaline. The potentiation of cardiac parasympathetic activity by pyridostigmine treatment was confirmed by the attenuation of restraint stress-induced tachycardia in both strains. Conclusions: Chronic stimulation of peripheral cholinergic system with pyridostigmine leads to the improvement of autonomic nervous system balance in SHR by increasing cardiac vagal tone and reducing sympathetic tone. Thus, chronic treatment with acetylcholinesterase inhibitors seems to be a promising therapeutic strategy for the restoration of autonomic balance in cardiovascular diseases.

The role of autonomic nervous system imbalance in the pathogenesis of hyperplastic laryngitis

A decrease in the mediator activity of nerve structures in organ tissues leads to the development of neurodystrophic changes and an increase in their sensitivity to certain influences. In these planets, it is important to assess the morphological characteristics of target structures, taking into account the neurodystrophic component of the disease. The aim of the study was to determine the activity of the peripheral adrenergic link of the trophic reflex and assessing the morphological features of the mucous membrane of the vocal folds in chronic hypertrophic laryngitis in patients with neurovegetative disorders. Materials and methods: the study involved 45 patients (37 men and 8 women) aged 23 to 72 years with a diagnosis of chronic hypertrophic laryngitis. An objective study of the upper respiratory tract, a cytological study of reprinted smears from the affected areas of the larynx, a study of the functional state of the ANS, as well as a histological and histochemical study of the removed tissue were carried out. Results. The examined patients were found to have dysfunction of the ANS in the form of insufficient or excessive autonomic support of activity. Morphological signs of keratinization of the epithelium of the mucous membrane of the vocal folds and its active proliferation, as well as dystrophic and atypical changes in cellular elements revealed as a sign of insufficient, tact and a sign of excessive vegetative support of activity. It was found that with insufficient vegetative support of activity, the proliferative activity of epithelial cells is more pronounced than that of a chemer with excess. The same applies to keratosis with atypia and dystrophic changes in the epithelium. Conclusions. The activity of the interstitial adrenergic nerve structures of the mucous membrane of the vocal folds correlates with the characteristics of autonomic activity. The weakening of the processes of synthesis, accumulation and excretion of neurotransmitter is associated with insufficient vegetative support of activity, and their strengthening is associated with excessive. The amount of neurotransmitter in peripheral nerve fibers and endings depends on the nature and intensity of manifestations of neurogenic dystrophies developing in executive tissues – targets of adrenergic innervation.

O015 Sleep, Stress, and Cognitive Fatigue in Canadian Wildland Firefighters

Abstract Background Wildland firefighting requires continuous attention while exposed to long working hours and sub-optimal sleep. These stressors may induce a state of cognitive fatigue, which poses a risk to worker safety due to impaired judgment and reduced awareness. Methods The current study employs a within-subject, observational design to examine the effect of sleep and schedule characteristics on variables related to stress and cognitive function. Cognitive function is measured subjectively, via validated 7-point scales (i.e. Samn-Perelli Fatigue Scale and Stanford Sleepiness Scale), and objectively, via reaction time on the psychomotor vigilance task. Sleep is measured via sleep log and wrist-worn actigraphy. Stress via autonomic nervous system imbalance is measured by changes in heart rate variability (i.e. chest monitor). Linear regression analyses will be performed to test if sleep or schedule variables predict stress or cognitive function. Progress to date A pilot study (N=4) was conducted during the 2021 fire season to inform methodology. As of July 2022, a representative sample of 50 firefighters (13 F) have been recruited across all regions of British Columbia (BC), Canada. Data collection for the current study is ongoing and will continue until September 2022. Intended outcome and impact This investigation entails both theoretical and applied benefits. Its direct relevance to occupational health and safety could improve worker safety (1) by providing insight and recommendations towards improved fatigue management policy within the BC Wildfire Service and (2) by testing the practicality of mobile tools designed to monitor levels of sleep, stress, and cognitive function.

Abstract 13303: Influence of ARNI on Cardiac Autonomic Nervous System

Background Mortality in heart failure with reduced ejection fraction (HFrEF) is associated with imbalance of cardiac autonomic nervous system (CANS). Sacubitril/ Valsartan (ARNI) reduces risk of death and HFrEF hospitalization. Whether ARNI exerts effects on CANS has not been studied. Accordingly, we prospectively compared heart rate variability (HRV) as a noninvasive measure of CANS before and after initiation of ARNI therapy. Methods: The study was as a single-arm prospective interventional study. Patients with HFrEF underwent echocardiography and standardized 30-minute 12-lead Holter ECG recording before and 3 months after initiation of ARNI therapy. Study endpoints were changes in HRV parameters (standard deviation of normal-to-normal intervals (SDNN), mean square of differences between consecutive R-R intervals (RMSSD), periodic repolarization dynamics (PRD) and deceleration capacity (DC) as well as left ventricular ejection fraction (LVEF) and heart rate (HR). Results: Between June 2021 and March 2022 we recruited 63 consecutive patients. At follow-up 48 (76.2%) patients were still on ARNI and therefore analyzed. Mean age was 65±13 years, 88% were male. All patients received identical beta-blockers dosage at baseline and follow-up. Heart rate was reduced by ~12% (P=0.005). SDNN increased by ~42% (P&lt;0.001), RMSSD by ~55% (P&lt;0.001) and ~DC by 370% (P&lt;0.001). No change in PRD was observed (P=0.13). These results were accompanied by increased LVEF (28±6% vs. 38±10%, P&lt;0.001) and reduced plasma nt-proBNP levels (5083±790 pg/ml vs. 1838±621 pg/ml, P=0.002). NYHA class improved from III to II. Conclusion Significant increase of parasympathetic CANS tone was observed after initiation of ARNI therapy as evidenced by decreased HR, increased DC, SDNN and RMSSD. Part of the beneficial effects of ARNI might be related to the accentuation of parasympathetic CANS modulating mortality risk and risk for HFrEF hospitalizations.