Predominance Of Parasympathetic Activity Research Articles

Location of Parasympathetic Innervation Regions From Electrograms to Guide Atrial Fibrillation Ablation Therapy: An in silico Modeling Study.

The autonomic nervous system (ANS) plays an essential role in the generation and maintenance of cardiac arrhythmias. The cardiac ANS can be divided into its extrinsic and intrinsic components, with the latter being organized in an epicardial neural network of interconnecting axons and clusters of autonomic ganglia called ganglionated plexi (GPs). GP ablation has been associated with a decreased risk of atrial fibrillation (AF) recurrence, but the accurate location of GPs is required for ablation to be effective. Although GP stimulation triggers both sympathetic and parasympathetic ANS branches, a predominance of parasympathetic activity has been shown. This study aims was to develop a method to locate atrial parasympathetic innervation sites based on measurements from a grid of electrograms (EGMs). Electrophysiological models representative of non-AF, paroxysmal AF (PxAF), and persistent AF (PsAF) tissues were developed. Parasympathetic effects were modeled by increasing the concentration of the neurotransmitter acetylcholine (ACh) in randomly distributed circles across the tissue. Different circle sizes of ACh and fibrosis geometries were considered, accounting for both uniform diffuse and non-uniform diffuse fibrosis. Computational simulations were performed, from which unipolar EGMs were computed in a 16 × 1 6 electrode mesh. Different distances of the electrodes to the tissue (0.5, 1, and 2 mm) and noise levels with signal-to-noise ratio (SNR) values of 0, 5, 10, 15, and 20 dB were tested. The amplitude of the atrial EGM repolarization wave was found to be representative of the presence or absence of ACh release sites, with larger positive amplitudes indicating that the electrode was placed over an ACh region. Statistical analysis was performed to identify the optimal thresholds for the identification of ACh sites. In all non-AF, PxAF, and PsAF tissues, the repolarization amplitude rendered successful identification. The algorithm performed better in the absence of fibrosis or when fibrosis was uniformly diffuse, with a mean accuracy of 0.94 in contrast with a mean accuracy of 0.89 for non-uniform diffuse fibrotic cases. The algorithm was robust against noise and worked for the tested ranges of electrode-to-tissue distance. In conclusion, the results from this study support the feasibility to locate atrial parasympathetic innervation sites from the amplitude of repolarization wave.

Cardiac autonomic modulation in juvenile idiopathic arthritis with use of biological medication: case report

Introduction: The introduction of biological medication in Juvenile Idiopathic Arthritis (JIA) proposes better therapeutic results with decreased pain and inflammation and consequent reduction in joint damage. The autonomic state can be a predictor for verifying the response to immunomodulation therapy. Thus, measuring heart rate variability can express autonomous behavior and possibly accompany the response to therapy through the expression of the inflammatory condition.
 Objective: Analysis of heart rate variability in a child with Juvenile Idiopathic Arthritis using the anti-Tumor Necrosis Factor.
 Methods: This is a clinical case report of an 8-year-old male with a diagnosis of JIA - oligoarticular form, using etanercept, admitted to Clínica Escola de Fisioterapia UNINORTE, Acre, Brazil in 2017. We analyzed laboratory and imaging tests, kinetic-functional evaluation, examination of cardiac autonomic modulation and physiotherapeutic treatment for analgesic, anti-inflammatory purposes, gaining flexibility, strength and postural re-education, according to CARE guidelines, case report guidelines.
 Results: After medication administration, there was a decrease in pain and normalization of serum creatinine (0.50 mg / dL) and CRP (less than 6 mg / dL) and an increase in erythrocyte sedimentation rate (17 mm3). In the examination of heart rate variability, the linear indices in the time domain showed a predominance of parasympathetic activity (RMSSD: 35ms), with decreased sympathetic control measured through the frequency domain (LF: 27.1 un). However, non-linear methods showed low variability with little dispersion of RR intervals.
 Conclusion: In the present report, the linear indices showed parasympathetic predominance and in the non-linear analysis a low heart rate variability with abnormal and insufficient adaptation of the autonomic nervous system in a child with juvenile idiopathic arthritis using biological medication.

RESILIENCE AS AN INTEGRAL CHARACTERISTIC OF PERSONALITY AMONG CADETS OF EMERCOM OF RUSSIA

Relevance. Resilience as an integrative resource of an individual, determining its psychological stability was studied among cadets of the Emercom of Russia to develop a psycho correctional program and increase the effectiveness of vocational training and health maintenance.Intention. To develop a model of resilience based on the identification of associated personality manifestations among the cadets of EMERCOM of Russia.Methodology. The study was conducted on the basis of the Far Eastern Fire and Rescue Academy a branch of the St. Petersburg University State Emergency Service Ministry of Emergency Situations among 150 cadets of the faculty of fire safety aged 19–21 years. Psychodiagnostic methods were used as well as psychophysiological rehabilitation complex “REACOR” for biofeedback training and UPFT 1/30 “Psychophysiologist”.Results and their analysis. Parameters of life meaningfulness increase proportionally to resilience. The analysis of terminal values showed that cadets with low resilience sought freedom, financially secure life, pleasures, while cadets with high resilience opted for development, continuous physical and spiritual self improvement. Indicators of internal motivation according to K. Zamfir test were lower in cadets with low and medium resilience vs high resilience. External negative motivation in the group with lower resilience, on the contrary, was higher due to avoidance prevailing over external positive motivation. Adaptation to new or changing conditions is quite complicated for cadets with low resilience and can be disturbed depending on external circumstances. Low resilience was associated with pedantic, anxious, cyclothymic, excitable and dysthymic personality accentuations, medium resilience was associated with cyclothymic and demonstrative accentuations, and high – with hyperthymic and demonstrative accentuations. Cadets with low and medium resilience commonly used confrontational coping strategy. Cadets with low resilience showed increase in flight – avoidance strategies in contrast to those with medium and high resilience (p < 0.05). Low resilience indicates a decrease in tension, the predominance of parasympathetic activity, pronounced inertness and passivity when performing tactical and technical actions. Cadets with high resilience demonstrated improved attention . Average and maximum response time was shorter in cadets with high resilience compared to those with low and medium resilience (p < 0.01), which indicates an increased concentration, activity, and speed. Greater response time in cadets with low resilience probably indicates their passivity and inertness when completing tasks (p < 0.01). After the heat chamber, average and maximum visual motor response time was longer in the group with low and medium resilience (p < 0.05). The structure of resilience includes biological (psychophysiological), social and psychological components. The predictors of resilience are the meaningfulness of life, such coping behaviors as self control, acceptance of responsibility, flight avoidance; personal adaptive potential and its components behavioral regulation and communicative potential; rigid and emotive accentuations; external negative motivation; psychophysiological indicators – vagosympathetic balance (LF / HF), average reaction time.Conclusion. An experimental study of the psychological factors of reactions to professional stressors among cadets made it possible to draw up a scheme of resilience as an integral characteristic of a personality, and to reveal its components.

Manipulation based on Fryette’s Laws increases heart rate variability and muscle flexibility in subjects with headache

Background: The sympathetic nervous system has a direct connection with the cervical spine, through the cervical ganglia, in the superior cervical ganglion; therefore the manipulation of the superior cervical spine could result on modifications of the heart rate variability (HRV). Objective: To evaluate the immediate effect of the manipulation based on the Fryette’s laws of the superior cervical spinal (SCS) on HRV and posterior chain flexibility (PCF) in subjects with headache. Methods/Design: Twelve volunteers of both genders (23.8 ± 2.8 years), who had complaints of headache, participated in the study. Before and immediately after the HRV assessment, PCF was measured with the assistance of Wells and Dillon’s Bench test. For this the volunteer remained seated with the spine erect, lower limbs extended and feet resting on the bench. Then it was requested maximum flexion of the trunk and measured with a ruler the achieved distance. The HRV was obtained by the cardiofrequencymeter Polar RS800cx and captured for continuous fifteen minutes with the volunteer resting in supine position. At five minutes of collection, with the volunteer in the same position, the SCS manipulation technique (Fryette’s Laws) was performed bilaterally. The HRV assessment was performed in the time domain by the RMSSD index of RR intervals (Matlab For Windows version 6.1) in two different moments: before and after the manipulation. Statistical analysis consisted of the Kolmogorov-Smirnov test and paired t-test for comparison of pre and post manipulation variables (p<0.05). Results: There was a significant increase (p = 0.004) in the RMSSD index after the manipulation (from 42.58 ± 24.52 ms before the manipulation to 51.25 ± 27.55 ms ten minutes after manipulation). The PCF also increased significantly (p = 0.03) after the SCS manipulation (from 17.65 ± 11.9 cm to 21.40 ± 13.8 cm). Conclusions: The manipulation of SCS increased the HRV through the increase of the RMSSD index indicating a predominance of parasympathetic activity, and improved the PCF of the studied volunteers, also reduced signs and symptoms of headache.

ORTHOSTATIC TACHYCARDIA: DIAGNOSTIC AND PROGNOSTIC VALUE OF VERY LOW FREQUENCY OF HEART RATE VARIABILITY

Researched physiological mechanisms of development of orthostatic tachycardia syndrome (POTS) on the basis of a complex spectral structure analysis of heart rate variability (HRV), its nonlinear behavior in relationship to energy oscillations, baroreflex and parasympathetic activity. There were several stages of research. The first stage: created the method of spectral analysis of individual components of Very Low Frequency (VLF). On the basis of comparative Fast Furrier Transform data with Welch filters, autoregression, continuous wavelet analysis and Hilbert–Huang transform, for the first time it was shown that VLF has separate 200, 100 and 50 s oscillations (VLF200, VLF100, VLF50). The second stage: for evaluation of physiological properties of separate oscillations, was analyzed VLF structure in three groups of patients (100 subjects): with a predominance of parasympathetic activity (HF) in the HRV spectrum; with a dominance of 10 s oscillations (LF); with a severe depression of energy in all components of the spectrum. It was established that the individual components of VLF (VLF100 and VLF50) have a certain stability and partial independence from the changes of peripheral autonomic indices (LF/HF) at loads of low intensity. The third stage: at an active orthostatic test, 20 subjects with orthostatic tachycardia were researched in a comparison to a control group of 20 subjects without tachycardia. Analyzed the specifics of the VLF structure (VLF100 and VLF50) alone and in a conjunction with the LF and HF, as well as heart rate and blood pressure in subjects with orthostatic tachycardia with a predominance of parasympathetic activity at functional tests of low intensity (seven-test, deep breathing) and at an active orthostatic test. Based on these studies it was concluded that the individual components in the VLF structure (VLF100, VLF50) can demonstrate reciprocal relationships at a load among themselves and in the LF/HF ratio, and play an adaptive role in the mechanisms of autonomic provision. Revealed the importance of VLF and its components 100 and 50 s oscillations at an orthostatic test in the prognosis of orthostatic tachycardia development. In patients with dysautonomia at high level of VLF100 power, or high VLF50 indices, tachycardia did not develop. In this case, VLF and its component parts did an important adaptive function and conversely, the low VLF50 indices contribute to orthostatic tachycardia. In the proposed model of the descending neurosomatic control of autonomic regulation of HRV a very important role plays both neurogenic ways of regulation, and neuro-hormonal-metabolic ways, manifested in the complex VLF structure. Regarded the choice of ways and optimal neurosomatic models of regulation at POTS.

Effect of Post-Weaning Individual Housing on Autonomic Responses in Male Rats to Sexually Receptive Female Rats

Post-weaning individual housing induces significant alterations in the reward system of adult male rats presented with sexually receptive female rats. In this study, we examined the effects of post-weaning individual housing on autonomic nervous activity in adult male rats during encounters with sexually receptive female rats to assess whether different affective states depending on post-weaning housing conditions are produced. Changes in heart rate and spectral parameters of heart rate variability indicated that in post-weaning individually housed male rats, both sympathetic and parasympathetic activity increased with no change in the sympathovagal balance, while in post-weaning socially housed male rats, both sympathetic and parasympathetic activity decreased with a predominance of parasympathetic activity. These two patterns of shifts in sympathovagal balances closely resembled changes in autonomic nervous activity with regard to classical appetitive conditioning in male rats. The autonomic changes in male rats housed individually after weaning corresponded to changes associated with the reward-expecting state evoked by the conditioned stimulus, and the autonomic changes observed in male rats housed socially after weaning corresponded to changes associated with the reward-receiving state evoked by the unconditioned stimulus. These results suggest that different affective states were induced in adult male rats during sexual encounters depending on male–male social interactions after weaning. The remarkable change caused by post-weaning individual housing may be ascribed to alteration of the reward system during sexual encounters induced by deficiency of intermale social communication after weaning.

Assessment of training-induced autonomic adaptations in athletes with spectral analysis of cardiovascular variability signals.

The purpose of this study was to assess the adaptive effects of endurance training on autonomic functions in athletes with spectral analysis of cardiovascular variability signals. Continuous ECG, arterial blood pressure (ABP), and respiratory signals were recorded from 15 athletes (VO2max > 55 ml/(kg.min)) and 15 nonathletes (VO2max < 45 ml/(kg.min)) in the sitting position during controlled respiration (tidal volume 700 ml and 15 cycles/min). The autonomic functions were assessed by the normalized low-frequency power (LF power: 0.06-0.14 Hz) and high-frequency power (HF power: the region of the respiratory frequency based on respiratory spectrum) obtained from the autospectra of the RR interval, systolic arterial pressure (SAP), and diastolic arterial pressure (DAP) variability signals. The spontaneous baroreflex sensitivity (BRS) was evaluated by the moduli, BRSLF and BRSHF, of the transfer function between the RR interval and SAP variability in LF and HF bands. The resting HR in athletes was significantly lower than that in nonathletes. In the case of RR interval spectra, the HF power was significantly higher in athletes than in nonathletes, whereas the LF power was significantly lower in athletes than in nonahtletes. These differences might reflect an alteration of sympathovagal interaction with a predominance of parasympathetic activity. However, there was no significant difference in the LF power of SAP and DAP autospectra, reflecting the sympathetic vascular control. The BRSLF and BRSHF were significantly higher in athletes as compared with nonathletes. These results indicate that endurance training induces autonomic imbalance (i.e., the enhanced vagal activities/the attenuated sympathetic tone), which may in part contribute to the resting bradycardia and an increase in the spontaneous BRS in athletes.