Autonomic Nervous Regulation Research Articles

The effect of circadian rhythm on the correlation and multifractality of heart rate signals during exercise

The heart rate variability (HRV) signals can well reflect the effect of exercise on cardiac autonomic nerve function, which can be used as the theoretical index for the development of the best physical exercise program. In this paper, we used multifractal detrended fluctuation analysis (MF-DFA), mass index spectrum and multifractality spectrum to analyze the heart rate variability signals, which have been obtained in these states, such as before, during and after exercise. The purpose is to establish the relationship between the nonlinear parameter of the signals and the autonomic nerve regulation, reveal the physiological mechanism for the effect of circadian rhythm. The result shows that exercise can decrease the correlation and increase the multifractality of heart rate variability signals. In different periods, the diversity of correlation and multifractality among different signals are obviously. The result shows that the correlation of heart rate variability signals was negatively correlated with sympathetic nerve regulation and positively correlated with vagus nerve regulation; the multifractality was positively correlated with sympathetic nerve regulation and negatively correlated with vagus nerve regulation. Further studies show that the function of heart system and the balance of autonomic nerve in the afternoon are more suitable for high-intense physical exercise.

Blood Pressure Variability in Acute Ischemic Stroke: Influence of Infarct Location in the Insular Cortex

Background: The aim of this study was to elucidate the influence of insular infarction on blood pressure (BP) variability and outcomes according to the region of the insular cortex affected. Methods: A total of 90 patients diagnosed with acute unilateral ischemic stroke were registered. The BP variability was calculated over 24 h after admission (hyperacute) and for 2–3 days after admission (acute). Patients were classified into groups of right and left, and then right anterior, right posterior, left anterior, and left posterior insular infarction. Results: Patients with insular infarction showed a significantly larger infarct volume, higher modified Rankin scale scores, and lower SD and coefficient of variation (CV) of ­systolic BP in the hyperacute phase than shown by patients without insular infarction (p < 0.01, p < 0.01, p = 0.02, and p = 0.03, respectively). The SD and CV of systolic BP in the hyperacute phase showed significant differences among the 3 groups with right insular infarction, with left insular infarction, and without insular infarction (p < 0.05 and p < 0.05, respectively). There was a tendency for the systolic BP variability to be lower in patients with right anterior insular infarction than in patients with infarcts in other areas. Conclusion: The right insular cortex, especially the anterior part, might be a hub for autonomic nervous regulation.

Recovery of the cardiac autonomic nervous and vascular system after maximal cardiopulmonary exercise testing in recreational athletes.

The body's adaptation to physical exercise is modulated by sympathetic and parasympathetic (vagal) branches of the autonomic nervous system (ANS). Heart rate variability (HRV), the beat-to-beat variation of the heart, is a proxy measure for ANS activity, whereas blood pressure (BP) is an indicator for cardiovascular function. Impaired vagal activity and lower BP is already described after exercise. However, inconsistent results exist about how long vagal recovery takes and how long post-exercise hypotension persists. Therefore, the aim of this study was to assess HRV and BP 1h after maximal cardiopulmonary exercise testing (CPET). HRV (Polar RS800CX), peripheral and central BP (Mobil-O-Graph®) were prospectively studied in 107 healthy volunteers (47 female, median age 29.0years) in supine position, before and 60min after maximal CPET. One hour after terminating CPET measures of HRV were still impaired and post-exercise BP was significantly reduced suggesting an improved vascular function compared to pre levels. HRV parameters post-exercise were 34.7% (RMSSD), 67.2% (pNN50), 57.2% (HF), and 42.7% (LF) lower compared to pre-exercise levels (for all p < 0.001). Median reduction in BP was 5mmHg for systolic BP (p < 0.001), and 4mmHg for diastolic BP (p = 0.016) and central systolic post-exercise (p = 0.005). One hour after terminating strenuous exercise, autonomic nervous regulation seems to be postponed which is reflected in reduced HRV, whereas the early recovery of the vasculature, post-exercise hypotension, is still preserved over the recovery period of 1 h.

Autonomic dysfunction in chronic pancreatitis and associated diseases of the digestive system

The article analyzes the literature on the role of autonomic dysfunction and other psychosomatic disorders in causing and progression of pancreatitis and associated gastrointestinal states. The influence of deviations of autonomic nervous system balance regulation on the emergence of hemodynamic, morphological, metabolic, energy disorders in aforementioned pathological conditions is studied. Pathogenic aspects of treatment of autonomic disorders are considered.

The Autonomic Repercussions of Fetal and Maternal Interaction in Pre-eclampsia

Abstract Pre-eclampsia (PE) is one of the severe complications of pregnancy that leads to fetal deterioration. The aim of the investigation was to determine the role of maternal respiratory sinus arrhythmia (RSA) in regulation of fetal circulatory system in case of healthy pregnancy and in PE. The investigation of maternal and fetal HRV and umbilical venous blood flow velocity spectral analysis in 106 patients at 34-40 weeks of gestation was performed. 30 of them had healthy pregnancy and were involved in the Group I. In Group II 44 pregnant women with mild-moderate PE were observed. 32 patients with severe PE were monitored in Group III. The maternal sympathetic overactivity modulated HRV in PE. The suppression of RSA was explored in preeclamptic patients. The Doppler spectrograms of the umbilical veinous blod flow had the oscillatory peak with a frequency about 0.5 Hz. The above peak characterized the participation of the maternal RSA in fetal hemodynamics. Strong relationship between maternal RMSSD and amplitude of RSA associated peak, maternal and fetal RMSSDs was found in healthy pregnancy. No considerable relationship was revealed between the maternal RMSSD and the amplitude of 0.5 Hz frequency peak, the maternal and fetal RMSSDs in the patients with severe PE. The maternal RSA propagated its influence on the fetal umbilical venous blood flow and the fetal autonomic nervous regulation in normal gestation. The control of fetal hemodynamics diminished in the mild-moderate PE and even disappeared in severe PE.

β-Adrenergic Responsiveness in the Type 2 Diabetic Heart: Effects on Cardiac Reserve.

This study aimed to determine the chronotopic and inotropic response of the type 2 diabetic heart to β-adrenergic stimulation. Eight people with uncomplicated T2D and seven matched controls performed a dual-energy x-ray absorptiometry scan and V˙O2peak test. Plasma catecholamines were determined at rest and during peak exercise. On a second visit, HR and left ventricular contractility were assessed using echocardiography during supine rest, parasympathetic blockade (atropine), and during incremental β-adrenergic stimulation (dobutamine). V˙O2peak and HR reserve were lower in T2D (P < 0.05) as expected. Both groups increased norepinephrine comparably (P = 0.23) during peak exercise; however, epinephrine increased less in the T2D group (P < 0.05). The dobutamine dose required to achieve 85% of age-predicted maximal HR was 36% higher in CON (P < 0.05). Resting HR was higher (P < 0.01) and stroke volume indexed to fat free mass was smaller (P < 0.05) in T2D. During dobutamine infusion the response (% change) in HR, end-diastolic volumeFFM, stroke volume, ejection fraction, and cardiac output were not different between the groups. However, HR was higher (P < 0.01) and end-diastolic volume indexed to fat free mass (P < 0.01), stroke volumeFFM (P < 0.01), ejection fraction (P < 0.05), and stroke work (P < 0.01) were lower in T2D. Although the type 2 diabetic heart worked at smaller volumes, the HR and contractile response to β-adrenergic stimulation were unaffected by diabetes. The reduced cardiac reserve observed in uncomplicated T2D was not explained by impaired myocardial sympathetic responsiveness but may reflect changes in the loading conditions or function of the diabetic left ventricle.

Sex and age differences in cardiac autonomic nervous regulation in response to recumbent positions

Not much research has been conducted to determine sex and age differences in autonomic nervous activity during different positions, namely the supine, left recumbent, and right recumbent positions. Our aim was to evaluate whether the left and right recumbent positions affect heart rate variability (HRV) differently than the supine position dose in young and old adults of both sexes. Twenty‐nine young male (22.5 ± 0.5 years), 29 young female (23.1 ± 0.7 years), 18 elderly male (76.1 ± 1.1 years), and 27 elderly female (72.6 ± 1.0 years) volunteers participated in this study. After lying in the supine position, the participants maintained each recumbent position in random order for 10 min. We recorded electrocardiographic data throughout this experiment to evaluate HRV. Heart rate during the left recumbent position was the lowest among the three positions regardless of age or sex. No significant differences were observed for low‐frequency (LF) HRV, high‐frequency (HF) HRV, or their ratio (LF/HF) in young adults of both sexes and elderly women when the position was changed from supine to recumbent. However, in elderly men, the LF/HF ratio during the right recumbent position was significantly lower than that during the supine position. While in supine position, elderly men showed high LF/HF ratios when compared to the other groups. These results suggest that the right recumbent position attenuates cardiac sympathetic nerve activity, which is expressed as the LF/HF ratio, in elderly male adults. Therefore, reduction in heart rate during the left recumbent position may not be associated with autonomic nervous activity.Support or Funding InformationThis work was supported in part by a Grant‐in‐Aid for Challenging Exploratory Research from the Japan Society for the Promotion of Science.

Functional state of the cardiovascular system in 13-year-old adolescents with different types of autonomic nervous regulation

The features of the functional state of cardiovascular system in 13-year-old children with different types of autonomic nervous regulation were studied. Children with normotonic and parasympathetic types of autonomic regulation were found to have the highest adaptation capacities. The autonomic nervous system influences the bioelectrical processes in myocardium, the duration of cardiac cycle phases, and cerebral blood flow. Schoolchildren aged 13 years with higher sympathetic activity have shorter duration of the cardiac cycle, the phase of isometric contraction, and diastole. They have a lower pulse blood flow rate and a higher tone of large and medium cerebral vessels. No relationship was revealed between the initial autonomic nervous regulation of heart rate and the type of adaptation of myocardium to physical dynamic loads, as well as the type of adaptation of cerebral circulation to mental stress.

Analysis of beat-to-beat blood pressure variability response to the cold pressor test in the offspring of hypertensive and normotensive parents.

Abnormal autonomic nervous regulation has an important role in the development of hypertension. As to whether blood pressure (BP) or BP variability represents the proper characteristics for predisposition to hypertension in Chinese young adults remains controversial. We studied the properties of the indices extracted from beat-to-beat BP during a 13 min cold pressor test (CPT). In this study, 69 Chinese young adults including 34 offspring of hypertensive parents (OHPs; 25.6±2.5 years) and 35 offspring of normotensive parents (ONPs; 25.3±2.3 years) were analyzed. We assessed the differences between the two groups regarding mean beat-to-beat BP and variability indices. Beat-to-beat BP variability indices included time-domain indices and frequency-domain indices. Our results showed that the differences in beat-to-beat systolic BP and mean BP levels between the OHPs and the ONPs were statistically significant (P<0.05). Furthermore, more BP variability indices in the frequency domain were significantly different between the two groups. We concluded that BP variability was superior to BP as an index to evaluate the cardiovascular and sympathetic reactivity to the CPT. Moreover, compared with time-domain BP variability, we found more differences in frequency-domain BP variability between the two groups, thus indicating that frequency-domain BP variability may be a potential index of predisposition to hypertension.

Autonomic imbalance captures maternal and fetal circulatory response to pre-eclampsia

BackgroundPre-eclampsia (PE) is a gestational disease featured by hypertension, arterial systemic vasculopathy, multiple organ failure and fetal compromise.The aim of the investigation was to determine the role of maternal respiratory sinus arrhythmia (RSA) in regulation of the fetal circulatory system in case of healthy pregnancy and in PE.MethodsThe investigation of maternal and fetal HRV and fetal CTG variables in 106 patients at 34–40 weeks of gestation was performed. 30 of them had healthy pregnancy and were involved in the Group I. In Group II 44 pregnant women with mild-moderate PE were observed. 32 patients with severe PE were monitored in Group III.ResultThe maternal sympathetic overactivity modulated HRV in PE by suppressing total power (TP) and parasympathetic tone. The lack of RSA was explored in preeclamptic patients. The centralization of hemodynamics was a result of the hypersympatheticotonia in severe PE. Fetal circulatory response to PE featured by an increased sympathetic tone. The modulated fetal CTG variables captured the suppression of fetal biophysical activity and the development of fetal distress in severe PE.Strong relationship between maternal and fetal TPs, maternal and fetal RMSSDs was found in healthy pregnancy. The correlations between the maternal and fetal TPs, the maternal and fetal RMSSDs in the patients with severe PE were disturbed.ConclusionThe maternal RSA propagated its influence on the fetal autonomic nervous regulation in normal gestation. The maternal and fetal hemodynamic coupling was reduced in PE.

自律神経と排卵(シンポジウム2「自律神経」, 第43回日本女性心身医学会学術集会報告)

自律神経と排卵(シンポジウム2「自律神経」, 第43回日本女性心身医学会学術集会報告)

An integrated anti-arrhythmic target network of compound Chinese medicine Wenxin Keli revealed by combined machine learning and molecular pathway analysis [corrected

Wenxin Keli (WK), a Chinese patent medicine, is known to be effective against cardiac arrhythmias and heart failure. Although a number of electrophysiological findings regarding its therapeutic effect have been reported, the active components and system-level characterizations of the component-target interactions of WK have yet to be elucidated. In the current study, we present the first report of a new protective effect of WK on suppressing anti-arrhythmic-agent-induced arrhythmias. In a model of isolated guinea pig hearts, rapid perfusion of quinidine altered the heart rate and prolonged the Q-T interval. Pretreatment with WK significantly prevented quinidine-induced arrhythmias. To explain the therapeutic and protective effects of WK, we constructed an integrated multi-target pharmacological mechanism prediction workflow in combination with machine learning and molecular pathway analysis. This workflow had the ability to predict and rank the probability of each compound interacting with 1715 target proteins simultaneously. The ROC value statistics showed that 97.786% of the values for target prediction were larger than 0.8. We applied this model to carry out target prediction and network analysis for the identified components of 5 herbs in WK. Using the 124 potential anti-arrhythmic components and the 30 corresponding protein targets obtained, an integrative anti-arrhythmic molecular mechanism of WK was proposed. Emerging drug/target networks suggested ion channel and intracellular calcium and autonomic nervous and hormonal regulation had critical roles in WK-mediated anti-arrhythmic activity. A validation of the proposed mechanisms was achieved by demonstrating that calaxin, one of the WK components from Gansong, dose-dependently blocked its predicted target CaV1.2 channel in an electrophysiological assay.

Age and Gender-Related Differences in Hypotensive and Hypertensive Responses to Stellate Ganglion Block

Purpose: The aim of the current study was to investigate: 1) Whether there is an association between age and changes in systolic blood pressure (SBP) after stellate ganglion block (SGB), and 2) Whether gender plays a role in hypotensive and hypertensive responses to SGB. Methods: We retrospectively reviewed SBP changes (ΔSBP) due to SGB, which were performed on 1641 subjects. SBP 30 min after SGB was compared to the baseline values. For the age study, average age of both sexes was calculated for six ranges of ΔSBP. For the gender study, the numbers of subjects (%) in various ranges of positive and negative values of ΔSBP were compared between men and women. Results: There was a significant association between age and both increasing (p < 0.05) and decreasing (p < 0.01) ΔSBP. Higher occurrence rates of negative ΔSBP were found in men as compared to women. On the other hand, higher occurrence rates of positive ΔSBP were found in women as compared to men. In addition, both men and women were found to have increasing ages as ΔSBP values get more positive or more negative. Conclusions: There was an association between age and blood pressure changes after SGB and the association is most likely due to age-related alteration of cardiovascular functions. The different changes of SBP between men and women after SGB may well be attributable to gender differences of autonomic nervous regulation; sympathetic dominant man versus, parasympathetic dominant women.

QRS COMPLEX FRAGMENTATION — AN IMPORTANT MARKER OF ABNORMAL DEPOLARIZATION

Aim . To investigate on the QRS complex fragmentation (fQRS) in patients with idiopathic ventricular arrhythmias (VA) . Material and methods. Totally, 125 patients, selected into 2 groups: 1st group — 100 patients (mean age 46,4±14,1 y., 69 females) with idiopathic VRD. Patients had predominating daytime arrhythmia (63%), more oftenly — monomorphic ventricular exstrasystolic complexes (VE) (59%), in 39% patients — paroxysms of nonsustained ventricular tachicardia. Structural pathology of myocardium was ruled out based on electrocardiography data, echocardiography, in some cases — magnetic resonance. Second, control group — 25 pts. (69,0±11 y. o., 12 females) with VRD of ischemic origin (coronary heart disease, myocardial infarction in anamnesis). In this group, polymorphic (84%) daytime (68%) VE predominated, and in 25% — nonsustained ventricular tachicardia. Analysis was done with Holter ECG in 12 leads (“KTResult 2”, “Inkart” JSC). Results. In the 1st group, fQRS of sinus complexes was registered in 2 patients (2%) and was transient. Relations in 24-hour dynamics of fQRS were not found. FQRS in VE was registered in 25 patients (25%). One patient had fQRS of sinus complexes as well as fQRS in VE. In 17 patients (68%) fQRS was found in VE. In controls, fQRS of sinus complexes was found in 6 patients (24%), fQRS of VE — in 23 (92%) and was permanent. Conclusion. The phenomenon of fQRS can be found during routine instrumental investigation (standard ECG or Holter ECG), and is more common for CHD patients, being significant criteria for repolarization processes evaluation. Looking for fQRS in patients with idiopathic VRD, probably, is related to dysbalance of autonomous nervous regulation that leads to electrical instability of myocardium. It cannot be ruled out that fQRS might be an early marker of cardiomyopathies. It is necessary to investigate on this phenomenon further and to find its place in risk stratification of sudden cardiac death of patients with no structural heart pathology.

A model-based method to measure baroreflex sensitivity.

This paper proposes a model-based method to quantitatively measure baroreflex sensitivity in autonomic nervous regulation of cardiovascular system. The method measures the continuous blood pressure and heart rate in orthostatic scenario, models dynamics of the baroreflex firing rate, solves parameters by optimization of measured blood pressure and heart rate variations. With this model, we can get the baroreflx sensitivity (BRS) inner indicators to evaluate the status of the autonomic nervous regulation system. Experimental results have shown the validation of the quantitative measures and the effectiveness of the method.

Deceleration and acceleration capacities of heart rate associated with heart failure with high discriminating performance.

Accurate measurements of autonomic nerve regulation in heart failure (HF) were unresolved. The discriminating performance of deceleration and acceleration capacities of heart rate in HF was evaluated in 130 HF patients and 212 controls. Acceleration capacity and deceleration capacity were independent risk factors for HF in males, evaluated by multiple logistic regression analysis, with odds ratios (ORs) of 5.94 and 0.13, respectively. Acceleration capacity was also an independent risk factor for HF in females, with an OR of 8.58. Deceleration capacity was the best cardiac electrophysiological index to classify HF in males, with an area under the receiver operating characteristic curve (AUC) of 0.88. Deceleration capacity was the best classification factor of HF in females with an AUC of 0.97, significantly higher than even left ventricular ejection fraction (LVEF). Acceleration capacity also showed high performance in classifying HF in males (0.84) and females (0.92). The cut-off values of deceleration capacity for HF classification in males and females were 4.55 ms and 4.85 ms, respectively. The cut-off values of acceleration capacity for HF classification in males and females were −6.15 ms and −5.75 ms, respectively. Our study illustrates the role of acceleration and deceleration capacity measurements in the neuro-pathophysiology of HF.

Orthostatic stress causes immediately increased blood pressure variability in women with vasovagal syncope

The cardiovascular and respiratory autonomic nervous regulation has been studied mainly by hemodynamic responses during different physical stressors. In this study, dynamics of autonomic response to an orthostatic challenge was investigated by hemodynamic variables and by diverse linear and nonlinear indices calculated from time series of beat-to-beat intervals (BBI), respiratory cycle duration (RESP), systolic (SYS) and diastolic (DIA) blood pressure. This study included 16 young female patients (SYN) with vasovagal syncope and 12 age-matched female controls (CON). The subjects were enrolled in a head-up tilt (HUT) test, breathing normally, including 5min of baseline (BL, supine position) and 18min of 70° orthostatic phase (OP). To increase the time resolution of the analysis the time series were segmented in five-minute overlapping windows with a shift of 1min. Hemodynamic parameters did not show any statistical differences between SYN and CON. Time domain linear analysis revealed increased respiratory frequency and increased blood pressure variability (BPV) in patients during OP meaning increased sympathetic activity and vagal withdrawal. Frequency domain analysis confirmed a predominance of sympathetic tone by steadily increased values of low over high frequency power in BBI and of low frequency power in SYS and DIA in patients during OP. The nonlinear analysis by symbolic dynamics seemed to be highly suitable for differentiation of SYN and CON in the early beginning of OP, i.e., 5min after tilt-up. In particular the index SYS_plvar3 showed less patterns of low variability in patients reflecting a steadily increase in both BPV and sympathetic activity. The proposed dynamical analysis could lead to a better understanding of the temporal underlying mechanisms in healthy subjects and patients under orthostatic stress.

Ocular autonomic dysfunction in glaucoma

SummaryThe retina relies primarily upon autoregulation of the retinal vasculature in cases of increased metabolic demand or reduced ocular perfusion pressure. The choroidal blood vessels are highly innervated by the autonomic nervous system, but are separated too far from the retina to respond to the local accumulation of vaso‐active metabolites. It could therefore be hypothesized that conditions interfering with either the autoregulation or the autonomic nervous regulation could render the retina at a higher risk of ischemic damage. Glaucoma has been associated with disturbances in both types of regulation. Retinal oximetry is capable of providing reproducible in vivo, non‐invasive measurements of the retinal vessel oxygen saturation and with the advent of enhanced depth imaging optical coherence tomography (EDI‐OCT), allowing a detailed non‐invasive evaluation of the choroid in‐vivo, renewed interest in the role of the choroid in the pathogenesis of glaucoma has grown.

AGE FEATURES OF CARDIOVASCULAR SYSTEM FUNCTIONAL PARAMETERS IN ADOLESCENTS LIVING IN DIFFERENT ARCTIC AREAS

Age features of autonomic nervous regulation of cardiac activity in 426 healthy adolescents aged 14-17 years living in areas of different latitudes, climatic and ecological conditions of the European North - in the Subpolar (64°30' N) and Polar (67°40' N) areas have been detected. Assessment of the cardiovascular system status was carried out with the use of the heart rate variability (HRV) and blood pressure (BP) parameters. The share of persons with borderline hypertension (BP level exceeded the limit of 90 percentile) also increased with age and reached 63% by the age of 17 years. Among the adolescents living in the Polar region according to the HRV and blood pressure indices, there was registered a significant increase in the proportion of persons with a predominance of sympathetic influences on the heart activity. The greatest adrenergic effects on the cardiovascular system were found in the 15-year-old adolescents of the Polar region, they had higher indices of systolic blood pressure, the heart rate and the regulatory systems stress index, as well as lower total HRV spectrum power in comparison with the 15-year-olds adolescents living in the Subpolar region.

Autonomic Nerve Regulation After Arm- or Leg Ergometer Exercising Eliciting the same heart rate level

Autonomic Nerve Regulation After Arm- or Leg Ergometer Exercising Eliciting the same heart rate level