Parasympathetic Component Research Articles

Cryolipolysis Does not Modify the Behavior and Recovery of Cardiac Autonomic Modulation.

The desire to reduce and remodel undesirable fatty deposits has increased the popularity and use of aesthetic procedures, among them, cryolipolysis. However, repercussions on the autonomic nervous system must be considered, since the decrease in cutaneous body temperature can have repercussions on sympathetic and parasympathetic components. The aim was to evaluate the behavior of cardiac autonomic modulation during and after a single application of cryolipolysis. A single-arm, prospective interventional study evaluated data from 13 women with a mean age of 22.38 ± 2.95years, who had an accumulation of abdominal fat of at least 1.5 mm, were using oral contraceptives, and were sedentary. A professional applied cryolipolysis in a single 40-min session. RR intervals were collected by means of a cardiofrequency meter, at rest prior to the technique for 10min, during the performance of the technique, and immediately after the end of the technique for a period of 50min. Heart rate variability (HRV) analysis was performed using time, frequency, and Poincaré plot indices. For the mean RR, SDNN, rMSSD, SD1, SD2, and LF [ms2] indices, the values increased during the execution of cryolipolysis when compared to rest. In the recovery period, increases in the mean values of the RR, SDNN, rMSSD, SD1, SD2, HF [ms2], LF [nu], and HF [nu] indices were also observed when compared to the baseline moment. Both during the technique and in the recovery period, there were changes in the behavior of HRV characterized by an increase in global and vagal indices. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Irritant Inhalation Evokes P Wave Morphological Changes in Spontaneously Hypertensive Rats via Reflex Modulation of the Autonomic Nervous System.

Irritant inhalation is associated with increased incidence of atrial fibrillation (AF) and stroke. Irritant inhalation acutely regulates cardiac function via autonomic reflexes. Increases in parasympathetic and sympathetic reflexes may increase atrial susceptibility to ectopic activity and the initiation of arrhythmia such as AF. Both age and hypertension are risk factors for AF. We have shown that irritant-evoked pulmonary–cardiac reflexes are remodeled in spontaneously hypertensive (SH) rats to include a sympathetic component in addition to the parasympathetic reflex observed in normotensive Wistar-Kyoto (WKY) rats. Here, we analyzed P wave morphology in 15-week old WKY and SH rats during inhalation of the transient receptor potential ankyrin 1 agonist allyl isothiocyanate (AITC). P Wave morphology was normal during vehicle inhalation but was variably modulated by AITC. AITC increased RR intervals (RRi), PR intervals, and the P Wave duration. In SH rats only, AITC inhalation increased the occurrence of negative P waves. The incidence of AITC-evoked negative P waves in SH rats was dependent on RRi, increasing during bradycardic and tachycardic cardiac cycles. Inhibition of both parasympathetic (using atropine) and sympathetic (using atenolol) components of the pulmonary–cardiac reflex decreased the incidence of negative P waves. Lastly, the probability of evoking a negative P Wave was increased by the occurrence of preceding negative P waves. We conclude that the remodeled irritant-evoked pulmonary–cardiac reflex in SH rats provides a substrate for altered P Wave morphologies. These are likely ectopic atrial beats that could provide a trigger for AF initiation in structurally remodeled atria.

Comparative immediate effect of different yoga asana on cardiac autonomic rhythm in healthy young volunteers

Modulation of cardiac autonomic tone is a topic of current interest in research because of its association with several cardiovascular autonomic diseases of public health importance. Yoga has proven benefit in balancing the cardiac autonomic tone. This study aimed to explore the intricate mind body mechanisms with special reference to the immediate effect of Padahastasana (PD) and Ardha Chakrasana (AD) on cardiac autonomic nervous system and to quantify the cardiovascular ANS response to different yogic asana. This was a Cross Sectional Study, conducted in autonomic function lab, of department of physiology, AII India Institute of Medical science, Raipur, India. Heart rate variability (HRV) was analyzed on 30 experienced yoga practitioners (EYP) with the average age of 32.9±9.71 year. All participants were healthy. Padahastasana and Ardhachakrasana were used as an intervention to evaluate heart rate variability. The time domain parameters show significantly increased parasympathetic component (SDNN, RMSSD, and SD2) after Padahastasana and Ardha chakrasana though increase is more after Ardha chakrasana. Interestingly sympathovagal balance was lowered after Padahastasana and increased after Ardha Chakrasana, although not statistically significant. This response may be due to a more increase in parasympathetic components after immediate Ardha Chakrasana. Our study showed the HRV has good specificity and positive predictive value for the quantifying autonomic response of Padahastasana and Ardha chakrasana. Backward bending is superior to forward bending and should be included in lifestyle intervention to reduce stress and anxiety disorder.

Linear and non linear measures of pupil size as a function of hypnotizability

Higher arousal and cortical excitability have been observed in high hypnotizable individuals (highs) with respect to low hypnotizables (lows), which may be due to differences in the activation of ascending activating systems. The present study investigated the possible hypnotizability-related difference in the cortical noradrenergic tone sustained by the activity of the Locus Coeruleus which is strongly related to pupil size. This was measured during relaxation in three groups of participants—highs (N = 15), lows (N = 15) and medium hypnotizable individuals (mediums, N = 11)—in the time and frequency domains and through the Recurrence Quantification Analysis. ECG and Skin Conductace (SC) were monitored to extract autonomic indices of relaxation (heart interbeats intervals, parasympathetic component of heart rate variability (RMSSD) and tonic SC (MeanTonicSC). Most variables indicated that participants relaxed throughout the session. Pupil features did not show significant differences between highs, mediums and lows, except for the spectral Band Median Frequency which was higher in mediums than in lows and highs at the beginning, but not at the end of the session.Thus, the present findings of pupil size cannot account for the differences in arousal and motor cortex excitability observed between highs and lows in resting conditions.

Attenuation of baroreflex sensitivity and heart rate variability is linked to reduced levels of nitric oxide in pregnant women having risks of developing gestational hypertension

ABSTRACT Purpose: Decreased baroreflex sensitivity (BRS) and sympathovagal imbalance (SVI) have been reported as a cardiovascular (CV) risk in gestational hypertension (GH). Nitric oxide (NO) has been implicated in pathophysiology of GH. In the present study, we assessed the link of CV risks (decreased BRS and SVI) to the plasma levels of NO in women having risk of developing GH. Materials and Methods: A total of 96 pregnant women having risk factors for GH were recruited for the study. The blood pressure variability (BPV), heart rate variability (HRV), plasma NO, marker of insulin resistance (HOMA-IR), lipid risk factors, inflammatory markers (hsCRP, interleukin-6), and malondialdehyde (MDA), the marker of oxidative stress (OS) were measured at 16th and 36th week. Link of various parameters to NO was assessed by correlation and multiple regression analysis. Results: Of HRV indices, parasympathetic components were decreased and sympathetic components were increased, BRS was decreased, NO was decreased, HOMA-IR, lipid risk factors, hsCRP, interleukin-6, and MDA were increased significantly at 36th week compared to 16th week of pregnancy. Most of the markers of cardiometabolic risk were correlated with NO. However, only the markers of CV risk (SVI and reduced BRS) were independently associated with decreased level of NO, but not the metabolic markers except interleukin-6. The independent contribution of BRS (β = 0.334, P < .001) to NO was found to be most significant. Conclusion: It was concluded that decreased BRS, SVI, and increased interleukin-6 are associated with reduction in NO in GH, which may possibly be linked to the development of CV risks in GH.

HEMODYNAMICS AND HEART RATE VARIABILITY UNDER ORTHOSTATIC CHALLENGE TEST IN YOUNG CAUCASIAN MEN: PART 1

Aim: To study hemodynamics and heart rate variability in response to an orthostatic challenge test among young Caucasian men born in the Russian Far North. Methods: Altogether, 172 healthy young men born in the Russian Far North comprised the sample. Cardiohemodynamic parameters in response to an active orthostatic test were studied using "Varicard" device and a tonometer. Results: A significant increase in heart rate, diastolic pressure, blood flow volume per minute, and reduction in systolic flow were observed among residents of the coastal areas as compared to the subjects from the continental areas. Young men of the coastal zone did not show any changes in the total peripheral vascular resistance during the test while the participants of the continental area showed a significant decrease in this indicator, which was most likely a compensatory reaction aimed at maintaining a sufficiently high stroke volume of blood as one of the mechanisms that proved to not allow the development of vasovagal syncope on the background of inadequate activation of the parasympathetic component and a decrease of the sympathetic regulation. It was revealed that the residents of the coastal zone demonstrated more adequate autonomic provision of hemodynamics in response to the orthostatic challenge test by reducing the activity of the parasympathetic link and the relative increase of the sympathetic regulation. The subjects of the intracontinental area tended to develop postural hypotension in response to the test, with a vagotonic type of reactivity and fewer correlations of cardiac hemodynamics with heart rate variability. Conclusion: Our results suggest that young men from the ontinental area develop a negative effect of synergistic amplification of dysregulatory manifestations of hemodynamic changes, autonomous and central contours of autonomic regulation, which can be considered a consequence of the allostatic adaptive tension caused by the particular area of residence.

The short-chain fatty acid propionate improved ventricular electrical remodeling in a rat model with myocardial infarction.

The short-chain fatty acid (SCFA) propionate (C3), a microorganism metabolite produced by gut microbial fermentation, has parasympathetic-activation effects. The cardiac autonomic rebalancing strategy is considered as an important therapeutic approach to myocardial infarction (MI)-produced ventricular arrhythmias (VAs). Thus, our research was designed to clarify the potential functions of the SCFA propionate in VAs and cardiac electrophysiology in MI rats. A hundred adult Sprague-Dawley rats were allocated to four groups: the sham group (200 mM sodium chloride), the sham + C3 group (200 mM propionate), the MI group (200 mM sodium chloride) and the MI + C3 group (200 mM propionate). In comparison with the sham group, propionate significantly increased the parasympathetic components heart rate variability (HRV) and acetylcholine levels, prolonged cardiac repolarization, induced STAT3 phosphorylation and up-regulated the c-fos expression in nodose ganglia and solitary nucleus. Propionate intake reduced the susceptibility to VAs. MI induced by coronary ligation caused a significant increase in the sympathetic components HRV, abnormal repolarization, global repolarization dispersion, norepinephrine and inflammatory cytokines, reduction and redistribution of Connexin 43 in the infarcted border zone, and activation of NFκB, which were attenuated in the MI + C3 group. Oral propionate supplementation, as a nutritional intervention, protected the heart against MI-induced VAs and cardiac electrophysiology instability partly by parasympathetic activation based on the gut-brain axis.

Heart rate variability and quality of life in dogs with mitral valve disease treated with metoprolol

Mitral valve disease (MVD) is a progressive disease that can reduce cardiac output. Activation of the sympathetic autonomic nervous system is one of the body’s first responses in order to maintain cardiac output, but may have deleterious effects on the cardiovascular system. This study investigated the effect of metoprolol on heart rate variability and quality of life in dogs with severe MVD (stage C, according to the guidelines of the American College of Veterinary Internal Medicine). Eight dogs between nine and thirteen years of age were enrolled and screening tests such as complete blood count, serum biochemistry profile, systolic blood pressure, thoracic radiographs, electrocardiogram, echocardiogram and long-term electrocardiography (24 hours) were performed. The patients were treated with enalapril, furosemide, spironolactone, and pimobendan until considered clinically stable, and metoprolol was then added to the therapy. One month later, all animals were re-assessed. Owners responded to a questionnaire about their dog’s quality of life before and after beta-blocker therapy. The value for pNN50 (percentage difference between adjacent N-N intervals more than 50 ms) was significantly higher (P=0.039) after treatment with metoprolol, indicating higher heart rate variability as indicated by the increased parasympathetic component. Furthermore, quality of life was improved in 30% of patients after metoprolol was initiated. The results suggest that treatment with beta-blockers in dogs with stage C MVD may yield additional benefits in comparison to standard CHF treatment.

Предэкзаменационный стресс как фактор риска нарушений функций сердечно-сосудистой системы у студентов с разным метаболическим статусом

Students who attend a medical HEE often face strain in their adaptation mechanisms when preparing for exams; it can create substantial preconditions for functional deregulation in body systems. The articles outlines some results obtained via examining heart rate variability (HRV) in students of the 2nd and the 3rd year attending the North Ossetia State Medical Academy who had different metabolic status in a period prior to exams. Our research goal was to assess the state of the vegetative nervous system and regulatory systems in students with different metabolic status (BMI&lt; 25; BMI=25–29.99; BMI=30–34.99.) who had to face excess stress during preparation to exams. Heart rate intervals were registered during five minutes in an examined person being at rest. HRV parameters were analyzed in time and frequency domains. We revealed that medical students had elevated activity of the sympathetic section in their vegetative nervous system (VNS) during a period prior to exams; in particular, it was apparent for the regulation system of the vasomotor center (PLF = 48.4%). Students’ bodies had apparent strain in their regulatory systems (SI=177.5 a.u.). Total activity of the regulatory system was significantly elevated (TP=2,293 msec2) due to central regulation levels. As students’ BMI grew, there was a decrease in activity of the parasympathetic component in vegetative regulation and heart rate management became more centralized (IC=3.2–4.5 a.u.). Students with Class 3 obesity had the maximum spectrum power of the superlow component in heart rate variability (PVLF=29.3%). HRV parameters analysis allows estimating whether adaptation processes in students’ bodies are adequate during preparation to exams; it can be done in screening mode and provides an opportunity to perform timely prevention activities.

Stress before exams as a risk factor causing functional disorders in the cardiovascular system in students with different metabolic status

Students who attend a medical HEE often face strain in their adaptation mechanisms when preparing for exams; it can create substantial preconditions for functional deregulation in body systems. The articles outlines some results obtained via examining heart rate variability (HRV) in students of the 2nd and the 3rd year attending the North Ossetia State Medical Academy who had different metabolic status in a period prior to exams. Our research goal was to assess the state of the vegetative nervous system and regulatory systems in students with different metabolic status (BMI&lt; 25; BMI=25–29.99; BMI=30–34.99.) who had to face excess stress during preparation to exams. Heart rate intervals were registered during five minutes in an examined person being at rest. HRV parameters were analyzed in time and frequency domains. We revealed that medical students had elevated activity of the sympathetic section in their vegetative nervous system (VNS) during a period prior to exams; in particular, it was apparent for the regulation system of the vasomotor center (PLF = 48.4%). Students’ bodies had apparent strain in their regulatory systems (SI=177.5 a.u.). Total activity of the regulatory system was significantly elevated (TP=2,293 msec2) due to central regulation levels. As students’ BMI grew, there was a decrease in activity of the parasympathetic component in vegetative regulation and heart rate management became more centralized (IC=3.2–4.5 a.u.). Students with Class 3 obesity had the maximum spectrum power of the superlow component in heart rate variability (PVLF=29.3%). HRV parameters analysis allows estimating whether adaptation processes in students’ bodies are adequate during preparation to exams; it can be done in screening mode and provides an opportunity to perform timely prevention activities.

Abstract 16157: Catheter Ablation Induces an Increase in Heart Rate With Discordant With a Decrease in Sympathetic Nerve Activity in Patients With Paroxysmal Atrial Fibrillation

Background/Introduction: Paroxysmal atrial fibrillation (PAF) is the most common arrhythmia and catheter ablation (CA) is selected with the aim of rhythm control. CA was reported to increase heart rate (HR), which explains the modulation on the cardiac autonomic nervous system. However, little is known about the relationship between heart rate, sympathetic nerve activity and parasympathetic nerve activity in patient with PAF. Purpose: The purpose of this study was to evaluate the effect of CA on direct recording of muscle sympathetic nerve activity (MSNA) and heart rate variability (HRV), and these influences on HR. Methods: This study was conducted as a prospective, observational study. Patients with PAF who were scheduled for CA were enrolled. We measured blood pressure, HR, body weight, brain natriuretic peptide (BNP), echocardiogram parameters, high frequency component as cardiac parasympathetic nerve activity and low frequency component as cardiac sympathetic nerve activity in HRV, and MSNA before and 12 weeks after CA. Results: 21 PAF patients participated in this study. After CA, E/e’ and Ln BNP were significantly reduced(10.6±2.9 to 9.2±2.6, p&lt;0.05. 3.8±1.3 to 3.3±1.6 log/pg/ml, p&lt;0.05, respectively) while no significant changes were observed in EF, SV, left atrial diameter, left ventricular end diastolic and systolic diameters. HR was significantly increased (61.3±7.8 to 71.1±7.6 beats/min, p&lt;0.05, respectively). However, the MSNA burst incidence and frequency were significantly decreased (65.4±12.6 to 41.3±13.4 bursts/100beats, p&lt;0.01, n=21. 39.8±8.8 to 28.1±9.6 bursts/min, p&lt;0.01, n=21. respectively). Also, the reduction in MSNA burst frequency was correlated with the increase in HR (r=0.57, 95%CI 0.183-0.804, p=0.00702). Ln Low frequency component in HRV was significantly decreased (5.72±1.75 to 3.85±2.13 log/ms 2 , p&lt;0.05, n=12), but Ln high frequency (HF) component was not changed . No significant relationship observed between increased HR and HF component. Conclusion: CA induced paradoxical increasing heart rate with the reduction in sympathetic nerve activity in patient with PAF. These findings suggest that CA might modulate autonomic interaction between sinus nodes and in left atrium with denervated in ganglionated plexi.

Heart rate variability in Dorper sheep in the fetal and neonatal periods until 120 days of age: Use of the technique in the field.

The evaluation of the autonomic cardiac functions may be performed through the analysis of the heart rate variability. Heart rate variability is defined as the fluctuations in the heart rhythm or rate, and represents a useful tool in the evaluation of the autonomic nervous system through the sympathetic and parasympathetic components, as well as its balance and its reflexes on the cardiorespiratory control system. Fetal electrocardiography provides important information regarding the well-being of the fetus since, in human fetuses, there are changes in the behavior of the fetal heart rate during the second and third trimesters of pregnancy due to an increase in parasympathetic activity. Therefore, considering the importance of evaluating fetal viability, this study aims at evaluating the behavior of fetal heart rate and heart rate variability in Dorper sheep, as well as the activity of the autonomic nervous system during fetal life and in newborn lambs. The species is often used in experimental studies and autonomic nervous system activity is a prognostic index, therefore, the diagnosis of modifications in the sympathovagal balance may represent an early index for fetal viability and well-being in lambs. The analyses were performed in 10 Dorper sheep during pregnancy and in 10 lambs after birth until 120 days of age. There was a decrease in the fetal heart rate and heart rate variability indexes during the fifth month of pregnancy, but without statistical significance for the period evaluated. The heart rate of the lambs decreased gradually until they were 21 days old. The indexes SDNN (standard deviation of RR intervals) and RMSSD (square root of the mean of successive differences between adjacent RR intervals) diverged according to age, being high at day 60. Fetal viability is relevant in sheep fetuses to avoid losses during pregnancy and risks to the health of the mother. In the species, there seems to be a predominance of parasympathetic activity starting from the 21st day of age. Heart rate variability may be employed as a tool in the evaluation of the fetus and development of lambs, since changes in its behavior may represent an adverse effect to fetal and neonatal health.

Heart rate variability as a potential diagnostic tool to predict compensatory hyperhidrosis after sympathectomy in patients with primary focal hyperhidrosis.

BackgroundPrimary focal hyperhidrosis (PFH) is associated with autonomic nervous activity, and studies investigating this association in patients with PFH are very important. Heart rate variability (HRV) is a simple and noninvasive electrocardiographic test showing activity and balance in the autonomic nervous system, which consists of sympathetic and parasympathetic components. The aims of this study are to investigate associations between autonomic nervous activity and hyperhidrosis characteristics using HRV and to investigate the association between HRV findings and compensatory hyperhidrosis (CH) after sympathectomy.MethodsFrom March 2017 to March 2020, 105 subjects with PFH who underwent preoperative HRV tests and sympathectomy were analyzed. All subjects underwent bilateral thoracoscopic sympathectomy. T2 sympathectomy was conducted for craniofacial hyperhidrosis, and T3 sympathectomy was conducted for palmar hyperhidrosis. The following HRV parameters chosen to investigate the association between hyperhidrosis and autonomic nervous activity were measured by time and frequency domain spectral analysis: (I) time domain: standard deviation of normal-to-normal interval (SDNN) and square root of mean squared differences of successive normal-to-normal intervals (RMSSD), (II) frequency domain: total power (TP) of power spectral density, very low frequency (VLF), low frequency (LF), and high frequency (HF). HRV parameters were analyzed according to hyperhidrosis type (craniofacial vs. palmar type), sweat reduction, and CH after sympathectomy. In addition, the independent HRV parameters influencing CH after sympathectomy were investigated with multivariate analysis.ResultsCraniofacial hyperhidrosis was significantly more prevalent in the old age group (P<0.001). Sweat reduction after sympathectomy was significantly more prominent in palmar hyperhidrosis (P=0.037), and CH after sympathectomy was more prominent in craniofacial hyperhidrosis (P<0.001). Palmar type patients exhibited significantly larger SDNN, RMSSD, TP, LF, and HF than craniofacial type patients (all P<0.001). There were no significant differences in any HRV parameters according to sweat reduction after sympathectomy. Low-degree CH was associated with significantly larger SDNN, RMSSD, TP, LF, and HF than high-degree CH (P<0.001, P<0.001, P=0.002, P=0.001, and P<0.001, respectively). Multivariate analysis showed that HF and age group were associated with CH after sympathectomy (P=0.007 and P=0.010, respectively).ConclusionsThis study shows that HRV can provide useful insight into the pathophysiology of PFH and enhance preoperative risk stratification of CH. Large-scale, prospective studies are required to determine the predictive value of HRV in patients at risk for subsequent CH after sympathectomy.

Disturbances of Autonomic Regulation of Cardiovascular System at Different Working Regimes with Night Shifts

Aim To study temporal and spectral characteristics of heart rhythm variability (HRV) in night shift workers.Materials and methods Along with traditional risk factors, conditions of labor contribute to development of cardiovascular morbidity, including night shift work, which can be associated with disorders of the autonomic regulation detected by analysis of HRV. This study included 100 healthy men. 74 of them were engaged in shift work, including 53 men with rotating shift work, 21 men with fixed night shifts, and 26 men with day-time work. HRV was analyzed by data of 5-min electrocardiogram recording (background recording and orthostatic test).Results Night-shift workers had decreases in total power of regulation (ТР, SDNN) and in the parasympathetic branch (HF, pNN50). Rotating night-shift workers displayed significant decreases in SDNN and pNN50 and pronounced changes in the VLF / LF / HF ratio in the orthostatic test.Conclusion In work with night shifts, the type of autonomic regulation differs from the "standard" functioning of the autonomic nervous system (ANS). This study showed different effects of night work regimens on HRV indexes. With the rotating shift work, the ANS dysregulation was more profound and was evident by a significant decrease in the ANS total tone and parasympathetic activity (SDNN, pNN50) compared to night shifts with fixed working hours. The excessive weakening of the parasympathetic component in the passive orthostatic test can be considered as an early marker for ANS maladaptation.

Can the mammalian dive response override posttraumatic stress disorder?

Author(s): Speciale, Alex | Abstract: Posttraumatic stress disorder (PTSD) is a burdensome condition that has been made worse by the Covid-19 pandemic and that can lead to suicide, especially among childhood trauma victims, rape victims, military service members, and law enforcement. PTSD is thought to be an evolutionary mechanism that functions to promote survival by heightening the stress response in an anticipatory fashion, allowing the organism to react quickly to recurring stressors or threats, even when stressors or threats are not present in the immediate environment. Frequent and sudden activation of the stress response can be uncomfortable and deleterious to health. The mammalian dive response (MDR) is another evolutionary adaptation that functions to promote survival by conserving oxygen when submerged underwater, and like the stress response, it disrupts the homeostatic environment. However, the physiological reactions induced by the MDR include slowing of the heart rate, conservation of oxygen, and conservation of energy, while the fight or flight response has opposite physiological effects. I hypothesize that frequent activation of the MDR and its parasympathetic components might inhibit brain regions involved with stress, and condition neural circuitry to anticipate aquatic submersion stimuli, thereby reversing the sympathetic mechanisms involved in the fight or flight response and PTSD.

Non-linear analysis of the heart rate variability in characterization of manic and euthymic phases of bipolar disorder

Background– Bipolar Disorder (BD) has been associated with autonomic nervous system (ANS) dysregulation, with a consequent increase in mortality. Recent work highlights the non-linear analysis of ANS function. Our objective was to compare ANS modulation using recurrence plots (RP) and symbolic analysis (SA) in manic and euthymic phases of BD to controls. Methods– Eighteen male patients (33.1 ± 12.0 years) were assessed during mania and at discharge in the euthymic phase compared and to a healthy group matched by age (33.9 ± 10.8 years). Electrocardiographic series (1000 RR intervals, at rest, in supine position) were captured using Polar Advantage RS800CX equipment and Heart Rate Variability (HRV) was analysed using RP and SA. Statistical analysis was performed using ANOVA with Tukey's post-test. The threshold for statistical significance was set at P < 0.05 and Cohen's d effect size was also quantified considering d > 0.8 as an important effect. The study was registered into the Clinical Trials Registration (ClinicalTrials.gov: NCT01272518). ResultsManic group presented significantly higher linearity before treatment (P<0.05) compared to controls considering RP variables. Cohen's d values had a large effect size ranging from 0.888 to 1.227. In the manic phase, SA showed predominance of the sympathetic component (OV%) with reduction of the parasympathetic component (2LV% and 2UV%) with reversion post treatment including higher Shannon Entropy (SE) indicating higher complexity. Limitations- short follow-up (1 month) and small number of patients. Conclusions- Non-linear analyzes may be used as supplementary tools for understanding autonomic function in BD during mania and after drug treatment.

P0164AMBULATORY BLOOD PRESSURE MONITORING AND CLINICAL SIGNIFICANCE IN PATIENTS WITH GASTROESOPHAGIAL REFLUX DISEASE

Abstract Background and Aims The patients with gastro-esophageal reflux disease (GERD) have distortion of sympathetic and parasympathetic components of the autonomic nervous system. The increase in sympathetic activity results in hyperkinetic circulation with peripheral vasoconstrictor and tachycardia and also regulates blood pressure with increase of renin in kidneys. We aimed to elucidate the patterns of pulse pressure in GERD patients, and also to investigate possible relationship between patterns of pulse pressure and laboratory/urinary parameters in adults Method The ambulatory blood pressure measuring was performed in all cases. Fifty patients in the reflux group and fifty individuals in the control group were included. Blood and urine specimens were examined. The individuals with cardiovascular disease, hypertension, malignancy, asthma disease, gastric peptic ulcer, hepatitis disease, tuberculosis, gastrointestinal disease excluding reflux, cerebrovascular disease, vasculitic disease, chronic alcohol usage, drugs with affect on autonomic system usage were excluded from study. Results We found lower diastolic blood pressure and increased pulse pressure values in reflux group and these were significant statistically. When patients were evaluated separately as men and women, this situation was found to be more pronounced in women. The decrease in serum potassium, chloride levels and the increase in serum LDL cholesterol, triglyceride levels in reflux group considered as statistically significant. Urinary parameters were similar in both groups. Non-dipper pattern found more common in reflux group, but considered as insignificant. The results were summarized in Table 1 and Table 2. Conclusion This study supports the hypothesis that increased vascular risk may be present in patients with GERD. Thus, perhaps a new population at risk for cardiovascular disease will be identified and mortality rates will able to decrease with early clinical evaluation.

Cardioprotective use of melatonin causes gender-specific changes of vegetative cardiac control in a setting of constant illumination

The aim of the work was to assess gender-specific differences in vegetative cardiac control with development of myocardial necrosis in a setting of constant illumination and use of melatonin. An experiment in mature laboratory breed albino rats of either sex simulated abnormal lighting regime. The simulation included keeping the animals for 10 days under constant illumination of 500 lux. On Day 11, myocardial necrosis (MN) was modeled by administering adrenaline (0.5 mg/kg intramuscularly); a follow-up electrocardiography was performed at 1 hour and 24 hours later to assess for heart rhythm variability. A half of animals was given melatonin 1 hour prior to MN modeling (5 mg/kg intraperitoneally). The animals kept under day/night balance were used as controls. The results have shown constant illumination to cause gender-specific changes in effects of vegetative nervous system on formation of heart rhythm in rats; the activity of the parasympathetic component increased in females and decreased in males. In females, the development of adrenaline-induced myocardial necrosis in a setting of constant illumination was accompanied by changes in cardiac interval (cardiointervalography) findings. The development of these changes with time was identical to that in day/night balance, with a more pronounced activity of the parasympathetic component and a synergetic enhancement of the sympathetic component. When exposed to constant illumination, males had a response different from that in day/night balance; their response to constant illumination was characterized by reduced activity of the parasympathetic component and by predominance of the sympathetic component. Cardioprotective use of melatonin was shown to increase parasympathetic tone compared to day/night balance; in males, this increase was evident at initiation of necrosis and in females, the increase was seen at the peak of necrotic foci formation in the myocardium.

Lacrimal Gland Postganglionic Innervation: Unveiling the Role of Parasympathetic and Sympathetic Nerves in Stimulating Tear Secretion

This commentary highlights the article by Jin etal that studied the regulation of lacrimal gland innervation by sympathetic and parasympathetic components.

Respiratory Sinus Arrhythmia Mechanisms in Young Obese Subjects.

Autonomic nervous system (ANS) activity and imbalance between its sympathetic and parasympathetic components are important factors contributing to the initiation and progression of many cardiovascular disorders related to obesity. The results on respiratory sinus arrhythmia (RSA) magnitude changes as a parasympathetic index were not straightforward in previous studies on young obese subjects. Considering the potentially unbalanced ANS regulation with impaired parasympathetic control in obese patients, the aim of this study was to compare the relative contribution of baroreflex and non-baroreflex (central) mechanisms to the origin of RSA in obese vs. control subjects. To this end, we applied a recently proposed information-theoretic methodology – partial information decomposition (PID) – to the time series of heart rate variability (HRV, computed from RR intervals in the ECG), systolic blood pressure (SBP) variability, and respiration (RESP) pattern measured in 29 obese and 29 age- and gender-matched non-obese adolescents and young adults monitored in the resting supine position and during postural and cognitive stress evoked by head-up tilt and mental arithmetic. PID was used to quantify the so-called unique information transferred from RESP to HRV and from SBP to HRV, reflecting, respectively, non-baroreflex and RESP-unrelated baroreflex HRV mechanisms, and the redundant information transferred from (RESP, SBP) to HRV, reflecting RESP-related baroreflex RSA mechanisms. Our results suggest that obesity is associated: (i) with blunted involvement of non-baroreflex RSA mechanisms, documented by the lower unique information transferred from RESP to HRV at rest; and (ii) with a reduced response to postural stress (but not to mental stress), documented by the lack of changes in the unique information transferred from RESP and SBP to HRV in obese subjects moving from supine to upright, and by a decreased redundant information transfer in obese compared to controls in the upright position. These findings were observed in the presence of an unchanged RSA magnitude measured as the high frequency (HF) power of HRV, thus suggesting that the changes in ANS imbalance related to obesity in adolescents and young adults are subtle and can be revealed by dissecting RSA mechanisms into its components during various challenges.