Autonomic Regulation Of Cardiac Rhythm Research Articles

The influence of combined effects of hyperbaria and hyperoxia on human heart rate variability during exercise strain

With the participation of 8 male volunteers, the dynamics of values of heart rate autonomic regulation were studied at response to physical load on a bicycle ergometer twice: both respirating by the room air under normobaric environment and simulating effects of the altered hyperoxic respiratory gas mixture (HRGM) by the rebreathe respiration methods from a rebreather at the high-pressure chamber (at «depth» 7 m). The devices and methods of Holter electrocardiogram monitoring were used under 24 hours research. The specialized software to analyze the data was used. The electrocardiogram (ECG) and calculated time series of cardiac intervals data obtained were subjected to mathematical processing to calculate statistical and spectral values of heart rate variability (HRV). Additionally, the geometric and nonlinear analysis methods of HRV were investigated. It has been established that influencing factors (compound and pressure of the HRGM) affect the autonomic regulation of heartbeats both at rest and during physical load. Clinical practitioners the HRV values are studied at rest and during strictly regulated tests, i.e. in stationary conditions. The analysis of non-stationary processes, for example, when it is necessary to continuously analyze data, the so-called transient processes under increasing psychological stress, to assess changes in the autonomic regulation of the heart during breathing of gas mixtures with different compositions (hypoxic therapy, hyperbaric oxygenation, etc.), and, especially during physically upload are used the methods of nonlinear and geometric analysis of HRV that are independent of the degree of nonstationary processes and, to some extent, of artifactual cardiac intervals. During the breathing the respiratory gas mixtures with an increased substance of O2 under conditions of high pressure, the activity of the parasympathetic branches of the autonomic nervous system (ANS) significantly increases. The nonlinear dynamics indexes reflect significant differences in the activity of autonomic components under experimental conditions in the direction of strengthening the parasympathetic links of the ANS. The use of nonlinear analysis values is more acceptable when evaluating obtained of non-stationary processes. In general, the study confirms that the regulatory response to the effects of hyperbaria and hyperoxia when performing a bicycle ergometer test with stepwise increase exercise strain is manifested by the prevalence of the activity of the parasympathetic part of the ANS autonomic regulation of cardiac rhythm compared to regular room air and barometric pressure.

Response of the cardiovascular system to heart rate variability biofeedback intervention in adolescents with different autonomic nervous tone living in northern and southern regions

BACKGROUND: The cardiovascular responses of adolescents during self-regulation are contingent upon their initial autonomic tone and place of residence.
 AIM: To investigate the dynamics of cardiovascular system indices during heart rate variability biofeedback (HRV BF) training in adolescents with different initial autonomic regulation of heart rhythm, taking into account their residence in the northern and southern regions.
 MATERIAL AND METHODS: Schoolchildren aged 1617 years, residents of the northwestern (n=55), northeastern (n=55) and southern (n=55) regions of the Russian Federation were examined. Heart rate variability (HRV) and blood pressure (BP) were recorded. Participants were divided into the following groups according to their baseline autonomic regulation of cardiac rhythm: vagotonics, normotonics and sympathotonics. Normotonics and sympathotonics additionally had a one-time HRV BF session to increase parasympathetic influences on heart rhythm.
 RESULTS: The northwestern/northeastern/southern samples revealed 29/7/16% vagotonics; 42/47/49% normotonics; and 29/46/35% sympathotonics. BP was significantly greater in sympathotonics compared to vagotonics and normotonics in in the northeastern region and sympathotonics in the northwestern and southern regions. HRV BF training was successful in all participants: HRV parameters responded to a greater extent in sympathotonics living in the northwestern region while their BP and baroreflex levels were relatively stable. Sympathotonics of the northeastern and southern regions were characterized by preservation of elevated HR after HRV BF accompanied by a significant decrease in BP and a pronounced baroreflex response.
 CONCLUSION: In the northwestern region, adolescents who are mainly decendants of migrants from the southern regions typically have sympathicotonia and increased vascular response to HRV BF. The descendants of natives of the northwestern region apparently inherited more advanced mechanisms of cardiovascular regulations in the conditions of the Arctic.

Changes in Heart Rate and Heart Rate Variability During Surgical Stages to Completed Fontan Circulation

Arrhythmia is related to heart rate variability (HRV), which reflects the autonomic nervous regulation of the heart. We hypothesized that autonomic nervous ganglia, located at the junction of the superior vena cava’s entrance to the heart, may be affected during the bidirectional Glenn procedure (BDG), resulting in reduced HRV. We aimed to investigate changes in heart rate and HRV in a cohort of children with univentricular heart defects, undergoing stepwise surgery towards total cavopulmonary connection (TCPC), and compare these results with healthy controls. Twenty four hours Holter-ECG recordings were obtained before BDG (n = 47), after BDG (n = 47), and after total cavopulmonary connection (TCPC) (n = 45) in patients and in 38 healthy controls. HRV was analyzed by spectral and Poincaré methods. Age-related z scores were calculated and compared using linear mixed effects modeling. Total HRV was significantly lower in patients before BDG when compared to healthy controls. The mean heart rate was significantly reduced in patients after BDG compared to before BDG. Compared to healthy controls, patients operated with BDG had significantly reduced heart rate and reduced total HRV. Patients with TCPC showed reduced heart rate and HRV compared with healthy controls. In patients after TCPC, total HRV was decreased compared to before TCPC. Heart rate was reduced after BDG procedure, and further reductions of HRV were seen post-TCPC. Our results indicate that autonomic regulation of cardiac rhythm is affected both after BDG and again after TCPC. This may be reflected as, and contribute to, postoperative arrhythmic events.

Variability and Pattern of Spontaneous Respiration in Different Types of Cardiac Rhythm Regulation of Highly Trained Athletes

Using spiroarteriocardiorhythmography, 202 highly qualified male athletes aged 22.6 ± 2.8 years, who are representatives of acyclic sports were examined. According to HRV (hearth rate variability), the types of the athletes' cardiac rhythm regulation were determined. There are 4 types of autonomic regulation of cardiac rhythm: Type I – indicates moderate stress, Type II – indicates a decrease in the functional state of regulatory systems, the development of fatigue, Type III – indicates the optimal state of regulation, Type IV – indicates overstrain of autonomic regulation or high fitness. The athletes with a predominance of central (types I and II) and autonomous (types III and IV) effects on the cardiac rhythm regulation are differentiated by indicators of total respiration power (TPR, (l/min)2) and power in the high frequency range (HFR), (l/min)2). Athletes with the type IV cardiac rhythm regulation had a more significant contribution of the low-frequency component (LFRn, n.u.) in the regulation of spontaneous respiration than athletes with type I and II cardiac rhythm regulation. In the type II regulation of cardiac rhythm there is a significant decrease in expiratory duration (s), which is also manifested by a significant increase in the ratio of inspiratory and expiratory phases, which may characterize expiratory insufficiency for this type.

Non-contact capacitive sensing for ECG recording in small animals

Rat electrocardiography (ECG) is frequently used in biomedical research as a model for exploring heart function in a wide variety of experimental conditions. Subcutaneous ECG is a common approach to record rat heart rhythm using implanted needle electrodes to sense the rat ECG signals with the animal under deep anesthesia. However, such an invasive measurement could cause inconvenience due to cumbersome animal preparation, and the anesthetics are likely to interfere with the autonomic regulation of cardiac rhythm. Most studies used the galvanic contact between animal limb and electrode sensing surface to record cardiac signals from small animals. However, the non-contact approach of capacitive ECG sensing for small laboratory animals has not been extensively investigated. This study aims to develop a non-contact ECG system to promote the ECG measurement of laboratory animals for biomedical research. The method utilizes the capacitive coupling technique to detect cardiac signals in awake rats (R-wave amplitude of only 0.2 mV) through a non-conductive layer. The proposed system generates non-contact ECG signals with distinguishable R-peaks at a limb-electrode capacitance above 8.5 pF and maximum through-thickness of the non-conductive layer of 0.4 mm for heart rate assessment. In conclusion, this study provides non-contact ECG monitoring based on capacitive electrodes to improve the throughput of ECG measurement procedures for biomedical research and establish a lower bound of coupling capacitance for non-contact application to heart rate. The new method is ideally suited for the rapid evaluation of autonomic regulation of heart rhythm in awake laboratory small animals.

Modulation of TRPV-1 by prostaglandin-E2 and bradykinin changes cough sensitivity and autonomic regulation of cardiac rhythm in healthy subjects

A neurogenic pathway, involving airway TRPV-1, has been implicated in acute cardiovascular events occurring after peaks of air pollution. We tested whether inhaled prostaglandin-E2 (PGE2) and bradykinin (BK) regulate TRPV-1 activity in vivo by changing cough response to capsaicin (CPS) and affecting heart rate variability (HRV), while also taking into account the influence of TRPV-1 polymorphisms (SNPs). Moreover, we assessed the molecular mechanism of TRPV-1 modulation in vitro. Seventeen healthy volunteers inhaled 100 μg PGE2, 200 μg BK or diluent in a randomized double-blind fashion. Subsequently, the response to CPS was assessed by cough challenge and the sympathetic activity by HRV, expressed by low (nLF) and high (nHF) normalized frequency components, as well as nLF/nHF ratio. Intracellular [Ca2+] was measured in HeLa cells, transfected with wild-type TRPV-1, pre-treated with increasing doses of PGE2, BK or diesel exhaust particulate (DEP), after CPS stimulation. Six functional TRPV-1 SNPs were characterized in DNA from each subject. Inhalation of PGE2 and BK was associated with significant increases in cough response induced by 30 μM of CPS (cough number after PGE2 = 4.20 ± 0.42; p < 0.001, and after BK = 3.64 ± 0.37; p < 0.01), compared to diluent (2.77 ± 0.29) and in sympathetic activity (nLF/nHF ratio after PGE2 = 6.1; p < 0.01, and after BK = 4.2; p < 0.05), compared to diluent (2.5–3.3). No influence of SNPs was observed on autonomic regulation and cough sensitivity. Unlike PGE2 and BK, DEP directly activated TRPV-1. Inhalation of PGE2 and BK sensitizes TRPV-1 and is associated with autonomic dysregulation of cardiac rhythm in healthy subjects.

Treatment-Related Changes in Heart Rate Variability in Children with Sleep Apnea.

Heart rate variability (HRV), a noninvasive indicator of autonomic regulation of cardiac rhythm, may represent the physiologic burden of obstructive sleep apnea (OSA). We hypothesized that the treatment-related effects of OSA on HRV in children are causally attributable to the improvement in OSA severity. Secondary analysis of outcomes from the Childhood Adenotonsillectomy Trial (CHAT). Analysis of database. Time- and frequency-domain HRV parameters along with polysomnographic (PSG) and demographic variables were obtained from the CHAT study, which compared early adenotonsillectomy (eAT) to watchful waiting (WW) in children with OSA. The relative contributions of PSG variables and covariates to each HRV parameter were quantified. The proportion of changes in HRV parameters causally attributable to changes in OSA severity, measured by the apnea-hypopnea index (AHI) and oxygen desaturation index (ODI), was estimated. In total, 404 children aged 5 to 10 years were included. The median (interquartile range) age was 6 (3-9) years. The median body mass index percentile was 82 (53), 195 (48%) children were male, and 147 (36%) were African American. The average heart rate during PSG was the strongest independent predictor of each HRV parameter (P < .001). Although eAT resulted in statistically significant changes in the majority of HRV parameters, these effects were not causally attributable to treatment-related changes in AHI or ODI. The average heart rate strongly modulates HRV in children with OSA. Although eAT results in discernible changes in HRV, it appears to not be causally attributable to specific treatment-related changes in AHI or ODI.

The impact of obesity on the parameters of cardiovascular remodeling, cerebral blood flow and autonomic regulation of cardiac rhythm in hypertensive patients

Objective. The aim of this study was to assess autonomic regulation disturbances, disorders of systemic, brain and intra-cardiac hemodynamics and to find out the features of vascular and cardiac remodeling in patients with arterial hypertension associated with obesity. Materials and Methods. The study involved 82 patients with stage II hypertension combined with obesity (39 men and 43 women) and 18 (12 men and 6 women) patients with essential hypertension with normal body weight. All the patients underwent general clinical examination, ECG Holter monitoring with heart rate variability analysis, 24h ABPM, duplex echocardiography and pulsed-wave Doppler of extracranial vessels. Results. Patients with essential hypertension associated with obesity have significantly higher average daily SBP by 9.4 % (p = 0.036), average DBP by 12.1 % (p = 0.027) and hypertension time index by 83.3 % (p = 0.012), diastolic size of LA by 11.1 % (p = 0.007), IVSTd by 23.7 % (p = 0.001), LVMI by 14.3 % (p = 0.022) and reduced volume-mass index of LV by 18.8 % (p = 0.013). In patients with essential hypertension with obesity we observed a significant decrease in Vmax in the left CCA by 16.5 % (p = 0.003) and in the right CCA by 12.6 % (p = 0.046), Vmean in the left CCA by 16.8 % (p = 0.001) and in the right CCA by 14.4 % (p = 0.009), reduced Vmax by 19.1 % (p = 0.002) and Vmean by 21.9% (p = 0.002) in the right ICA. Levels of Vmax and Vmean in the left MCA in hypertensive patients with obesity were lower by 10.2% (p = 0.043) and 12.5 % (p = 0.044), while the index of vascular reactivity sensitive to hypercapnia in the left MCA was lower by 14.6 % (p = 0.015). In overweighed patients with hypertension the linear Vmax in the left VA was lower by 13.9 % (p = 0.015) and Vmean 14.5 % (p = 0.013), in the right VA Vmax and Vmean were lower by 17.7 % (p = 0.011) and 25.8 % (p = 0.003). In group with hypertension and obesity Vmean in BA showed a reduction by 17.3 % (p = 0.021), and index of reactivity sensitive to hypercapnia by 23.1 % (p = 0.002). Hypertensive patients with obesity and with normal body weight did not differ by temporal and spectral parameters of HRV. Index LF/HF in both groups exceeded 2 cu. Conclusions. The presence of obesity in patients with essential hypertension is accompanied by significantly higher average SBP and DBP, daily hypertension time index according to 24h ABPM, a significant increase in diastolic LA size, IVSTd, LVMI and decrease of LV volume-mass index, decreased blood flow in CCA, right ICA, left MCA, both VA and BA, index of vascular reactivity sensitive to hypercapnia in the left MCA and BA. In patients with essential hypertension regardless of whether obese or of normal body weight sympathetic part of the autonomic nervous system prevails.

The Insufficiency Type of Metabolic Balance and Nutritional Status in Patient With Heart Failure

A lot of data has been accumulated at present on the metabolic and nutritional insufficiency in patients with chronic heart failure (CHF). Researchers have noted an actuality of the study of nutritional and metabolic insufficiency in CHF patients as independent factors affecting the course of CHF and because of its relationship with triggers of inflammation, sympathetic-adrenal system, and markers of functional state of the cardiovascular system (CVS). In some works attention has been given to relationship of nutritional and metabolic insufficiency with autonomic regulation of cardiac rhythm. Attempts have been made to systematize obtained data, create contemporary pathophysiological portrait of CHF development and highlight prevailing mechanisms of progression of the disease. This review summarizes accumulated data on nutritional insufficiency in patients with CHF and systematizes metabolic changes according to types of metabolism and CHF functional class. We have also made an attempt of creating figurative representation of pathophysiological mechanism of development of nutritional insufficiency in CHF. We have emphasized the problem of inadequate knowledge on contribution of inflammatory markers in development of nutritional insufficiency especially in patients with I-II functional classes of CHF. We also present suggestions concerning strategy of studying nutritional insufficiency in CHF, its classification according to CHF functional class, stratification of risk factors of its development, and the methods of its prevention and correction.

P184. Heart rate variability and its modulation by auricular branch of vagus nerve stimulation in Parkinson’s disease

Objective Brainstem nuclei, especially the efferent dorsal motor nucleus of the vagal nerve may degenerate early in the course of Parkinson’s disease (PD). The vagus nerve includes axons which emerge from or converge onto different efferent and afferent brainstem nuclei, all functionally and anatomically interconnected. The auricular branch of the vagus nerve (ABVN) is known to be connected to autonomic regulation of cardiac rhythm. In the present prospective, cross-sectional observational study we tested heart rate variability (HRV) at rest and the influence ABVN stimulation. Methods Fifty patients with PD (age 64 ± 9 years, 21 females Hoehn & Yahr stage 2.3 ± 0.7, UPDRS III 20.9 ± 7.2, disease duration 6.4 ± 4.5 y) and 50 controls (age 64 ± 11 y, 21 females) were investigated. RR intervals were measured on electrocardiograms at normal breathing for 3 min under resting condition and for around 317 min during left or right transcutaneous ABVN stimulation. Several indices of the heart rate variability (HRV) were automatically computed (time and frequency domain): standard deviation of NN intervals (SDNN), RR-intervals/maximal frequency (HFV index), power spectral analysis in the low (ln(LF), 0.05–0.15 Hz) and in the high frequency spectrum (ln(HF), 0.15–0.5 Hz) and the low frequency/high frequency ratio (ln(LF/HF) ratio). Results Most HRV parameters were lower in PD patients compared to controls: SDNN ( p = 0.027), TINN ( p = 0.013), HRV index ( p = 0.003), LF ( p = 0.014) and HF (p = 0.039). The ln(LF/HF) ratio, that is believed to mirror sympathovagal balance did not differ between both groups ( p = 0.137). However, a significant decrease of ln(LF/HF) ratio during right ABVN stimulation in comparison to the resting condition across all subjects was found ( p = 0.002), but not following left ABVN stimulation ( p = 0.238). Other parameters were not significantly influenced by right or left ABVN stimulation. UPDRS III correlated negatively with ln(LF) ( r = −0.369, p = 0.014) and ln(HF) ( r = −0.291, p = 0.050) indicating a (weak) association between impairment in cardiac autonomic modulations and motor deficit. Conclusions Heart rate variability is considerably impaired in PD. Parasympathetic activity seems to be relatively enhanced over sympathetic activity by ABVN stimulation. However, our findings do not point to prominent dysfunction of processing afferent information from ABVN and its connected parasympathetic efferent pathway in PD.

Poststroke atrial fibrillation: Cause or consequence?

Poststroke atrial fibrillation (AF) represents up to 1 of 4 overall AF cases in acute ischemic stroke. Current guidelines recommend oral anticoagulation for every ischemic stroke patient in whom AF is diagnosed. However, in some cases, AF detected after acute ischemic stroke may be short-lasting and perhaps a nonrecurrent autonomic and inflammatory epiphenomena of stroke. The autonomic regulation of cardiac rhythm constitutes an integrated relay system. The highest level of control is exerted by the cerebral cortex, particularly the insula. The onset of AF may be associated with an imbalance of sympathetic and parasympathetic activity, a common consequence of insular infarctions. This autonomic imbalance and an interruption in the cerebral regulation of the intrinsic cardiac autonomic system constitute the most likely mechanisms responsible for the autonomic pathway. The role of inflammation in the genesis of AF within the first few days after ischemic stroke may occur through inflammatory mediators stimulating the intrinsic autonomic system and by direct damage to atrial myocardium. To what extent poststroke AF is the cause or a consequence remains uncertain.

Use of a physiological monitoring model for comprehensive evaluation of adaptive capacities in schoolchildren during learning activity. Part I. Influence of various motor activity regimens on cardiac rhythm induces in junior schoolchildren

The dynamics of changes in the indices of the autonomic regulation of cardiac rhythm was studied in junior schoolchildren during adaptation to physical exercise. An analysis of variation pulsometry parameters throughout the school year showed the role of the sympathetic and parasympathetic parts of the autonomic nervous system in the formation of body adaptive reactions to various motor activity regimens.

Autonomic Regulation of Cardiac Rhythm in 7- to 16-Year-Old Children Survivors of Oncological Disease

Autonomic Regulation of Cardiac Rhythm in 7- to 16-Year-Old Children Survivors of Oncological Disease

Changes in the cardio-vascular function in healthy persons and in patients with ischemic heart disease during sleep

The purpose of this study was to investigate the autonomic regulation of the cardiovascular system during sleep in health and disease. The examination included 396 subjects: 29 healthy subjects and 367 patients with ischemic heart disease, of whom 149 had left-ventricular failure and 214 hypertension. Sleep quality and the presence of obstructive sleep apnea syndrome were evaluated by polysomnography; the character of autonomic regulation of cardiac rhythm and hemodynamics was determined by computerized testing during night sleep and an active orthostatic test immediately before and after sleep. The results permitted the authors to conclude that autonomic regulation may be restored to various degrees in health and disease, depending on the pathology level. The sleep quality influenced the restoration of hemodynamics more than that of the cardiac rhythm, mainly when obstructive sleep apnea syndrome was present.

ABSTRACT SESSION 12: AUTONOMIC REGULATION OF CARDIAC RHYTHM

Pacing and Clinical ElectrophysiologyVolume 16, Issue 4 p. 866-867 ABSTRACT SESSION 12: AUTONOMIC REGULATION OF CARDIAC RHYTHM First published: April 1993 https://doi.org/10.1111/j.1540-8159.1993.tb01680.xCitations: 5AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume16, Issue4April 1993Pages 866-867 RelatedInformation