糖尿病植物神经病变病人心率变异的非线性定量分析

目的：研究糖尿病人植物神经病变与心率变异的关系。对象：正常对照组和根据临床有无糖尿病神经病变（ＤＡＮ）分组的糖尿病病人,方法：应用２４小时动态心电图对正常和糖尿病人进行心率变异的线性,非线性散点图和非线性定量参数分析,结果：单纯糖尿病组ＳＤＮＮ,ＳＤＡＮＮ和ＰＮＮ５０低于正常组（Ｐ〈０．０５）;糖尿病＋ＤＡＮ组各项线性时域分析指标均低于正常和单纯糖尿病组（Ｐ〈０．０１－０．００１）,散点图分析结果     

血管紧张素Ⅱ对家兔心率变异的影响

目的:研究血管紧张Ⅱ(AngⅡ)对家兔心率变异(HRV)影响的机制。方法:分别给家兔静脉输注生理盐水,AngⅡ,溴化六烃季胺(HEXB),HEXB+AngⅡ检测安静状态下连续5 min的心电图并进行HRV的时域和频域分析。结果:血管紧张素Ⅱ组的时域指标SDNN和RMSSD较对照组明显降低,频域指标低频(LF)升高,而高频(HF)和总功率(TP)明显降低;HEXB+AngⅡ组与HEXB组相比无明显区别。结论:交感神经阻断剂HEXB不能影响AngⅡ的作用,AngⅡ主要通过抑制中枢自主神经的传出,降低迷走神经张力来降低HRV。     

Ingestion of coffee polyphenols suppresses deterioration of skin barrier function after barrier disruption,concomitant with the modulation of autonomic nervous system activity in healthy subjects

The aim of this study was to evaluate the effect of consumption of coffee polyphenols (CPPs) on the autonomic nervous system activity and decreased skin barrier function caused by sodium dodecyl sulfate (SDS) treatment. In this single-blind, placebo-controlled study, ten healthy male subjects consumed either a beverage containing CPPs or a placebo beverage for four weeks. CPPs significantly suppressed the deterioration in skin barrier function and skin moisture content induced by SDS treatment after the third week. Furthermore, in the heart rate variability analysis, CPPs significantly produced an increase in parasympathetic nervous activity, and a decrease in sympathetic nervous activity after the four weeks of beverage consumption. These results suggest that CPPs might influence the regulation of the autonomic nervous system and contribute to the suppressive effect on deterioration of skin barrier function.     

Nocturnal exposure to intermittent 60 Hz magnetic fields alters human cardiac rhythm

Heart rate variability (HRV) results from the action of neuronal and cardiovascular reflexes, including those involved in the control of temperature, blood pressure and respiration. Quantitative spectral analyses of alterations in HRV using the digital Fourier transform technique provide useful in vivo indicators of beat-to-beat variations in sympathetic and parasympathetic nerve activity. Recently, decreases in HRV have been shown to have clinical value in the prediction of cardiovascular morbidity and mortality. While previous studies have shown that exposure to power-frequency electric and magnetic fields alters mean heart rate, the studies reported here are the first to examine effects of exposure on HRV. This report describes three double-blind studies involving a total of 77 human volunteers. In the first two studies, nocturnal exposure to an intermittent, circularly polarized magnetic field at 200 mG significantly reduced HRV in the spectral band associated with temperature and blood pressure control mechanisms (P = 0.035 and P = 0.02), and increased variability in the spectral band associated with respiration (P = 0.06 and P = 0.008). In the third study the field was presented continuously rather than intermittently, and no significant effects on HRV were found. The changes seen as a function of intermittent magnetic field exposure are similar, but not identical, to those reported as predictive of cardiovascular morbidity and mortality. Furthermore, the changes resemble those reported during stage II sleep. Further research will be required to determine whether exposure to magnetic fields alters stage II sleep and to define further the anatomical structures where field-related interactions between magnetic fields and human physiology should be sought. Bioelectromagnetics 19: 98–106, 1998. © 1998 Wiley-Liss, Inc.     

Causal interactions between the cerebral cortex and the autonomic nervous system

Mental states such as stress and anxiety can cause heart disease.On the other hand,meditation can improve cardiac performance.In this study,the heart rate variability,directed transfer function and corrected conditional entropy were used to investigate the effects of mental tasks on cardiac performance,and the functional coupling between the cerebral cortex and the heart.When subjects tried to decrease their heart rate by volition,the sympathetic nervous system was inhibited and the heart rate decreased.When subjects tried to increase their heart rate by volition,the parasympathetic nervous system was inhibited and the sympathetic nervous system was stimulated,and the heart rate increased.When autonomic nervous system activity was regulated by mental tasks,the information flow from the post-central areas to the pre-central areas of the cerebral cortex increased,and there was greater coupling between the brain and the heart.Use of directed transfer function and corrected conditional entropy techniques enabled analysis of electroencephalographic recordings,and of the information flow causing functional coupling between the brain and the heart.     

Caloric restriction may reverse age-related autonomic decline in humans

Caloric restriction (CR) retards aging in laboratory rodents. No information is available on the effects of long-term CR on physiologic markers of aging and longevity in humans. Heart rate variability (HRV) is a marker for cardiac autonomic functioning. The progressive decline in HRV with aging and the association of higher HRV with better health outcomes are well established. Heart rate variability assessment is a reliable tool by which the effects of CR on autonomic function can be assessed. Time- and frequency-domain analyses compared 24-h HRV in 22 CR individuals aged 35-82 years and 20 age-matched controls eating Western diets (WD). The CR group was significantly leaner than the WD group. Heart rate was significantly lower, and virtually, all HRV values were significantly higher in the CR group than in the WD group (P < 0.002). Heart rate variability in the CR individuals was comparable with published norms for healthy individuals 20 years younger. In addition, when differences in heart rate (HR) and HRV between CR and WD were compared with previously published changes in HRV induced in healthy adults given atenolol, percent differences in each measure were generally similar in direction and magnitude and suggested declines in sympathetic and increases in parasympathetic modulation of HR and increased circadian variability associated with CR. These findings provide evidence that CR has direct systemic effects that counter the expected age-associated changes in autonomic function so that HRV indexes in CR individuals are similar to those of individuals 20 years younger eating WDs.     

Deterioration of autonomic neuronal receptor signaling and mechanisms intrinsic to heart pacemaker cells contribute to age‐associated alterations in heart rate variability in vivo

We aimed to determine how age‐associated changes in mechanisms extrinsic and intrinsic to pacemaker cells relate to basal beating interval variability (BIV) reduction in vivo. Beating intervals (BIs) were measured in aged (23–25 months) and adult (3–4 months) C57BL/6 male mice (i) via ECG in vivo during light anesthesia in the basal state, or in the presence of 0.5 mg mL^?1 atropine + 1 mg mL^?1 propranolol (in vivo intrinsic conditions), and (ii) via a surface electrogram, in intact isolated pacemaker tissue. BIV was quantified in both time and frequency domains using linear and nonlinear indices. Although the average basal BI did not significantly change with age under intrinsic conditions in vivo and in the intact isolated pacemaker tissue, the average BI was prolonged in advanced age. In vivo basal BIV indices were found to be reduced with age, but this reduction diminished in the intrinsic state. However, in pacemaker tissue BIV indices increased in advanced age vs. adults. In the isolated pacemaker tissue, the sensitivity of the average BI and BIV in response to autonomic receptor stimulation or activation of mechanisms intrinsic to pacemaker cells by broad‐spectrum phosphodiesterase inhibition declined in advanced age. Thus, changes in mechanisms intrinsic to pacemaker cells increase the average BIs and BIV in the mice of advanced age. Autonomic neural input to pacemaker tissue compensates for failure of molecular intrinsic mechanisms to preserve average BI. But this compensation reduces the BIV due to both the imbalance of autonomic neural input to the pacemaker cells and altered pacemaker cell responses to neural input.     

Biofeedback and Dance Performance: A Preliminary Investigation

Alpha-theta neurofeedback has been shown to produce professionally significant performance improvements in music students. The present study aimed to extend this work to a different performing art and compare alpha-theta neurofeedback with another form of biofeedback: heart rate variability (HRV) biofeedback. Twenty-four ballroom and Latin dancers were randomly allocated to three groups, one receiving neurofeedback, one HRV biofeedback and one no intervention. Dance was assessed before and after training. Performance improvements were found in the biofeedback groups but not in the control group. Neurofeedback and HRV biofeedback benefited performance in different ways. A replication with larger sample sizes is required.     

AUTONOMIC CONTROL OF HEART RATE AFTER EXERCISE IN TRAINED WRESTLERS

The objective of this study was to establish differences in vagal reactivation, through heart rate recovery and heart rate variability post exercise, in Brazilian jiu-jitsu wrestlers (BJJW). A total of 18 male athletes were evaluated, ten highly trained (HT) and eight moderately trained (MT), who performed a maximum incremental test. At the end of the exercise, the R-R intervals were recorded during the first minute of recovery. We calculated heart rate recovery (HRR_60s), and performed linear and non-linear (standard deviation of instantaneous beat-to-beat R-R interval variability – SD1) analysis of heart rate variability (HRV), using the tachogram of the first minute of recovery divided into four segments of 15 s each (0-15 s, 15-30 s, 30-45 s, 45-60 s). Between HT and MT individuals, there were statistically significant differences in HRR_60s (p <0.05) and in the non linear analysis of HRV from SD1_30-45s (p <0.05) and SD1_45-60s (p <0.05). The results of this research suggest that heart rate kinetics during the first minute after exercise are related to training level and can be used as an index for autonomic cardiovascular control in BJJW.     

电刺激迷走神经对蟾蜍心率和心率变异的影响

目的:观察不同频率迷走神经刺激对蟾蜍离体心脏的心率及心率变异的影响。方法:将蟾蜍心脏和右侧迷走交感干离体后,以不同频率电刺激神经,记录心电图曲线并作心率变异性(HRV)分析。结果:交感神经阻断后,电刺激迷走交感干,心率(HR)显著下降(P0.01),全部正常心动周期的标准差(SDNN)和相邻正常心动周期差值的均方根(RMSSD)显著升高(P0.01),不同频率刺激组之间没有明显差异;与对照组相比,各指标变化较大;给药组0.2Hz时高频(HF)显著升高(P0.01),低频/高频比值(LF/HF)明显降低(P0.05),0.8Hz时HF和LF/HF接近刺激前水平。结论:一定范围内增加刺激频率,迷走神经降低心率的作用增强;没有交感神经调节条件下的迷走神经对心率和心率变异的调节可能存在不同的机制。     

迷走神经和交感神经系统不同活动状态对心率变异性的影响

实验在氯醛糖加氨基甲酸乙酯麻醉的新西兰兔上进行。记录血压、心率、心电图并对心电Ｒ－Ｒ间期（ＲＲＩ）作功率谱密度（ＰＳＤ）分析。以单调性电刺激和低频率的波动性电刺激分别刺激减压神经、疑核和右侧迷走神经外周端,观察到低频率的波动性刺激对增加ＰＳＤ中低频成分（ＬＦ）的作用比单调性电刺激更大（Ｐ〈０．０５）。注射新福林仅在头一个２５６个心动周期时间内引起总变异性（ＴＶ）、ＬＦ、ＰＳＤ中高频成分（ＨＦ）。Ｌ     

The circadian rhythm of heart rate variability

Purpose: In recent years, the measurement of heart rate variability (HRV) has gained ground even outside research settings in everyday clinical and outpatient practice and in health promotion. Methods: Using the search terms “heart rate variability”, “hrv” and “circadian”, a systematic review was carried out in the PubMed database to find original work that analysed the course of HRV parameters over a 24-h period. Results: A total of 26 original studies were found. Almost all the studies detected a circadian rhythm for the HRV parameters analysed. HRV increased during the night in particular and a nighttime peak during the second half of the night was identified. Conclusions: HRV follows a circadian rhythm. But until today, there isn′t any possibility to make quantitative statements about changes over the course of the day for planning short-term measurements. More qualitative studies must be carried in order to close this knowledge gaps.     

Sleep patterns and nocturnal cardiac autonomic activity in female athletes are affected by the timing of exercise and match location

The aim of the current study was to analyze the influence of the timing of training and matches, and match location, on sleep pattern and nocturnal cardiac autonomic activity in female soccer players. A total of 17 female soccer players (age: 21.6 ± 2.3 years; mean ± SD) wore wrist actigraph units and heart rate (HR) monitors during night-sleep throughout 18 night-training days (NTD), 18 resting days (RD), and 6 match-days (MD; 3 away-matches [AM] and 3 home-matches [HM]) of the competitive period. Training load was quantified by session rating of perceived exertion (sRPE), heart rate (HR), training impulse (TRIMP), and subjective well-being. In NTD, sleep onset time and total sleep time were significantly impaired compared to MD (+ 1:47 [0:48; 1:55] hours and ?1:35 [?1:42; ?0:57] hours, respectively; p< 0.001; mean difference ± 95% confidence interval [CI]) and RD (+ 1:31 [0:52; 1:49] hours and ?1:26 [?1:28; ?0:55] hours, respectively; p< 0.001). In AM, sleep onset time was delayed compared to HM (+ 0:36 [0:12; 0:44] hours; p< 0.001). Sleep latency was higher in NTD compared to RD (+ 4 [2; 5] min; p< 0.001), as well as after AM compared to HM (+ 5 [1; 7] min; p< 0.001). HR during sleep was significantly increased after NTD and MD compared to RD (+ 4 [1; 5] b.p.m and + 3 [1; 4] b.p.m, respectively; p< 0.001). Furthermore, HR variability decreased after NTD and MD compared to RD (e.g., lnRMSSD, ?0.09 [?0.18; ?0.08] ln[ms] and ?0.17 [?0.27; ?0.11] ln[ms], respectively; p< 0.001). Overall, the time of day for soccer practice (i.e., training at night) and match location (i.e., away matches) may cause disruption in sleep patterns and/or in autonomic cardiac activity in female soccer players. Additionally, playing official matches during the day and training at night may affect nocturnal cardiac autonomic activity by decreasing vagal-related modulation and increasing HR during sleep.     

Basal metabolic rate and autonomic nervous system dysfunction in men with spinal cord injury

Objectives: The purpose of this study was to determine the relationship between autonomic nervous system dysfunction and basal metabolic rate (BMR), and the effect of spasticity on basal metabolic rate. Research Method and Procedures: Twenty men (11 paraplegic and 9 tetraplegic) with American Spinal Injury Association (ASIA)‐A and ‐B grade chronic spinal cord injury (SCI) participated in this study. Total body fat mass and lean tissue mass were measured in all participants using DXA by standard methods. Patients were allocated into 2 groups to determine the effect of autonomic nervous system dysfunction on BMR: Group I (T6 and upper‐level injuries with history of autonomic dysreflexia) and Group II (T7 and lower‐level injuries without history of autonomic dysreflexia). Measurements of BMR were determined by indirect calorimetry under standardized conditions. Results: There were 13 patients in Group I and 7 patients in Group II and the difference between these two in terms of time since injury, BMI, age, weight, lean tissue mass, BMR, and BMR/kg were not significant. Conclusion: We concluded that autonomic nervous system dysfunction does not affect BMR, and it might be ignored in considering energy needs in spinal cord injury.     

Central nervous system involvement in the autonomic responses to psychological distress

Psychological distress can trigger acute coronary syndromes and sudden cardiac death in vulnerable patients. The primary pathophysiological mechanism that plays a role in stress-induced cardiac events involves the autonomic nervous system, particularly disproportional sympathetic activation and parasympathetic withdrawal. This article describes the relation between psychological distress and autonomic nervous system function, with a focus on subsequent adverse cardiovascular outcomes. The role of the central nervous system in these associations is addressed, and a systematic review is presented of studies examining the association between stress-induced central nervous system responses measured by neuroimaging techniques and autonomic nervous system activation. Results of the systematic review indicate that the primary brain areas involved in the autonomic component of the brain-heart association are the insula, medial prefrontal cortex, and cerebellum (based on 121 participants across three studies that fitted the inclusion criteria). Other areas involved in stress-induced autonomic modulation are the (anterior) cingulate cortex, parietal cortex, somatomotor cortex/precentral gyrus, and temporal cortex. The interaction between central and autonomic nervous system responses may have implications for further investigations of the brain-heart associations and mechanisms by which acute and chronic psychological distress increase the risk of myocardial infarction, cardiac arrhythmias, and sudden cardiac death.     

Step behaviour and autonomic nervous system activity in multiparous dairy cows during milking in a herringbone milking system

Behavioural and cardiac responses of multiparous dairy cows (n=24) during milking in a 2×4 stall herringbone milking system were evaluated in this study. Heart rate (HR), parasympathetic tone index (high frequency component, HF) of heart rate variability and sympathovagal balance indicator LF/HF ratio (the ratio of the low frequency (LF) and the HF component) were analysed. Measurement periods were established as follows: (1) standing calm (baseline), (2) udder preparation, (3) milking, (4) waiting after milking in the milking stall and (5) in the night (2 h after milking). Step behaviour was recorded and calculated per minute for the three phases of the milking process (udder preparation, milking and waiting after milking). HR was higher during udder preparation and milking compared with baseline (P=0.03, 0.027, respectively). HF was significantly lower than baseline levels during waiting in the milking stall after milking (P=0.009), however, during udder preparation, milking and 2 h after milking did not differ from baseline (P>0.05, in either case). LF/HF during the three phases of the milking process differed neither from baseline levels nor from each other. Steps occurred more often during waiting after milking than during udder preparation (P=0.042) or during milking (23; P=0.017). Our results suggest that the milking procedure itself was not stressful for these animals. After milking (following the removal of the last teat cup and before leaving the milking stall), both decreased parasympathetic tone (lower HF) and increased stepping rate indicated a sensitive period for animals during this phase.     

不同年龄健康被试者心率变异性的谱分析研究

对不同年龄健康男性被试者卧、立位条件下,心率变异性（ｈｅａｒｔ ｒａｔｅ ｖａｒｉａｂｉｌｉｔｙ,ＨＲＶ）谱高、低频成分随年龄变化的规律进行研究。结果表明：虽然各年龄组间卧、立位时的静息平均心率并无显著差别,但ＨＲＶ却随年龄的增长而明显降低,青年组ＨＲＶ谱高、低频谱峰功率的显著高于中年组、中老年组及老年组（Ｐ〈０．０５或Ｐ〈０．０１）;ＨＲＶ谱低频谱功率、高频谱功率及总功率均随年龄增长呈指数衰减规     

The influence of short-term sedentary behavior on circadian rhythm of heart rate and heart rate variability

The notion that sedentary behavior is harmful to human health is widespread. Little is known about the short term influence of sedentary behavior on heart rate (HR) and heart rate variability (HRV) circadian rhythms. Therefore the purpose of the present study was to examine the influence of short term sedentary behavior on the circadian rhythms of HR and HRV using cosine periodic regression analysis. Sixteen healthy young students were included in a randomized crossover study. All subjects underwent 24-h ECG Holter monitoring in two different states of physical activity, an active condition (more than 15,000 steps per day) and a sedentary condition (less than 1,000 steps per day). Hourly mean values were calculated for HR and HRV, and then were evaluated using cosine periodic regression analysis. The circadian rhythm parameters, amplitude, mesor, and acrophase for HR and HRV variables were obtained. As a result, the significance of the circadian rhythm was confirmed for all variables in each condition. The measure of fit R2 value was decreased in sedentary condition. The amplitude of the sedentary condition was significantly smaller than that of the active condition with respect to HR (7.94 ± 1.91 bpm vs. 15.4 ± 3.93 bpm, p < 0.001), natural log of the high frequency measurement (lnHF) (0.38 ± 0.21 ms2 vs. 0.80 ± 0.28 ms2, p < 0.001), and low frequency/high frequency ratio (LF/HF) (0.75 ± 0.54 vs. 1.24 ± 0.69, p = 0.008). We found that sedentary behavior not only significantly lowered the amplitude of HR and HRV variables, but also might have led to weakness of the circadian rhythm of the HR and HRV variables.     

The effect of wai tan kung on autonomic nervous modulation in the elderly

The decline in physical capacity in the elderly can be ameliorated by low-velocity, low-impact exercises. Wai tan kung (WTK), a traditional Taiwanese conditioning exercise, is suitable for older people. This study evaluated the effect of WTK on autonomic nervous modulation in the elderly. Twenty WTK practitioners and 20 normal controls were recruited in this study. The stationary state spectral heart rate variability (HRV) measures, hemodynamics, and spirometry between the WTK group and normal controls and sequential changes in HRV measures and hemodynamics after WTK were compared. We found that the standard deviation and coefficient of variation of RR intervals, total power, low frequency power (LFP), and normalized LFP (nLFP) in WTK practitioners before WTK were all significantly higher than those of normal controls. After WTK, the normalized high-frequency power increased (nHFP) significantly from 27.7±13.2 normalized units (nu) before WTK to 37.6±16.0 nu 30 min after WTK, and to 39.8±20.1 nu 60 min after WTK. In contrast, LFP/HFP decreased significantly from 1.3±1.0 before WTK to 1.0±0.9 30 min after WTK and to 0.8±0.6 60 min after WTK. We concluded that in the short term, WTK enhances vagal modulation and suppresses sympathetic modulation, whereas in the long term, WTK enhances sympathetic modulation without compromising vagal modulation of the elderly. Thus WTK is good health-promoting calisthenics that can be recommended to the elderly.     

学龄前儿童不同距离往返跑后HR和HRV改变的比较*

目的: 筛选一种适用于评估学前儿童速度和心功能的测试方法。方法: 选取某幼儿园30名健康儿童作为实验对象,分别建立“10 m、20 m和30 m往返跑”的运动模型,通过佩戴人体能耗检测仪的方式,监测其运动前后心率和心率变异性(HRV)指标的变化特征,进而通过计算其运动负荷和生理负荷指数,通过HRV时域、频域和庞莱恩散点图参数的变化,判断学前儿童在不同距离往返跑后心脏交感神经和迷走神经的活性与支配功能状态。结果: 儿童10 m、20 m和30 m往返跑依次为中、大和超大强度的范围;HRV指标测试结果显示:与运动前基线值相比较,三种往返跑后的R-R间期标准差(SDNN)均呈现显著性的降低;儿童30 m往返跑后,除了低频与高频的比值(LF/HF)显著升高(P<0.01),其余频域指标以及庞莱恩散点图参数较基线值均有不同程度的降低(P<0.05,0.01);此外,与10 m往返跑后相比较,儿童20 m往返跑后LF呈现显著性的增加(P<0.01),其余HRV指标均无显著性变化,但30 m往返跑后的HRV频域指标和庞莱恩散点图参数均不同程度呈现显著降低(P<0.05,0.01),且LF/HF值超出正常参考值范围。结论: 20 m往返跑后儿童的心交感神经活性和迷走神经活性变化不显著、综合调节能力未下降,心功能安全性较好。