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1.
目的 探讨中枢硫化氢(H2S)对正常大鼠平均动脉血压的调节及其机制.方法 将微量H2S饱和盐溶液一次性和连续注射入麻醉大鼠侧脑室(ICV),观察注药后血压、心率和呼吸的变化.结果 ICV一次性注射不同剂量的H2S饱和盐溶液后可引起血压先急剧降低而后迅速升高,心率减慢,呼吸幅度增加和呼吸频率减慢,并存在显著的剂量和时间依赖关系.ICV连续注射H2S可显著升高血压,但对心率和呼吸没有影响.ICV注射一次性注射K+-ATP通道开放剂Pinacidil可显著的降低血压,但心率和呼吸没有显著变化;ICV一次性注射K+-ATP通道阻断剂glibenclamide对血压、心率和呼吸没有显著的影响;但预先ICV注射glibenclamide可阻断H2S的降低血压和减慢心率的作用,对呼吸没有影响.预先静脉注射酚妥拉明对血压没有明显的影响,却显著抑制ICV给予H2S产生的升高血压减慢心率效应.结论 本工作提示H2S是调节心血管活动的一个重要的中枢活性因子,其降低血压的效应是通过K+-ATP通道和影响呼吸有关系,而升压效应是通过激活交感神经的活性.  相似文献   

2.
目的:了解心率变异性(heart rate variability,HRV)在不稳定型心绞痛(unstable angina pectoris,UAP)发病中的作用及其用于病情严重程度判断的价值;了解美托洛尔对UAP患者HRV的影响。方法:选择年龄、性别相匹配的UAP患者、SAP患者和健康人各60例做动态心电图检查,经Holter软件分析进行HRV时域指标的比较。UAP组动态心电图检查后加用美托洛尔25-50 mg/d(分两次口服),20天后重复动态心电图检查。结果:1UAP组与正常组比较各项指标均降低(P0.01)。2正常人HRV具有昼夜节律变化的特点,UAP组HRV昼夜节律变化性降低。3UAP病人服用美托洛尔后,心肌缺血、心律失常得到改善。结论:1.UAP患者心脏自主神经活性主要是副交感神经活性受损,交感神经活性相对占优势。2.无合并症的UAP病人HRV呈昼夜节律性降低。3.美托洛尔可改善UAP患者HRV。  相似文献   

3.
The aim of this study was to investigate the natural history of the circadian rhythm of blood pressure (BP) and heart rate (HR) in 10 patients with heart failure (class IV of the New York Heart Association), who underwent heart transplantation because of primary congestive cardiomyopathy. The control group was 10 age-matched clinically healthy subjects. The BP and HR monitor-ings were performed before and after transplantation. Preoperatively, analysis of variance and cosinor methods validated the occurrence of a statistically significant BP and HR circadian rhythm in cardiopathic patients. Over the 4 days after surgery, both the cosinor method and serial section analysis were unable to validate a 24-h periodicity for BP and HR in patients with heart transplants. Six months after surgery, the BP and HR circadian rhythm was not detected as well. One year after transplantation. the BP and HR circadian rhythm was statistically validated. The recovery of the BP and HR circadian rhythm 1 year after heart transplantation can be regarded as a clinical sign of a reacquired susceptibility to neurovegetative chronoregulation.  相似文献   

4.
目的:探讨2型糖尿病(T2DM)患者心率变异性(HRV)与心率减速力(DC)的相关性及其对自主神经功能的评估价值。方法:选取2018年1月~2019年12月期间合肥市第一人民医院收治的120例T2DM患者为研究对象,纳入实验组,其中单纯T2DM患者69例(单纯T2DM组),T2DM伴周围神经病变(DPN)患者51例(DPN组),另选同期在我院进行心功能检查的健康志愿者120例作为对照组。所有受试者均进行24h动态心电图检查,根据检查结果计算HRV值[总标准差(SDNN)、两个相邻RR间期互差(PNN50)、差值均方根(RMSSD)]和DC值,根据各组受试者的DC值,统计对比各组的猝死风险,并分析T2DM患者DC值与HRV各项指标的相关性。结果:对照组、单纯T2DM组、DPN组的SDNN、PNN50、RMSSD、DC值依次降低(均P0.05)。对照组、单纯T2DM组、DPN组各猝死风险等级分布整体比较差异有统计学意义(P0.05),单纯T2DM组、DPN组猝死高危比例显著高于对照组,且DPN组猝死高危比例高于单纯T2DM组(均P0.05)。经Pearson相关分析,T2DM患者的DC值与SDNN、PNN50、RMSSD呈明显的正相关(P0.05)。结论:T2DM患者的DC值、HRV指标均低于正常人群,合并DPN的T2DM患者猝死风险明显提高,DC值与HRV指标间存在明显的正相关,可作为T2DM患者自主神经功能状态评估的重要指标。  相似文献   

5.
森林群落呼吸量的研究方法及其应用的探讨   总被引:13,自引:0,他引:13  
依据树木的形态特征和森林的结构特点,论述了森林群落呼吸量的研究方法和原理,利用北京山地3种典型森林群落,即:油松(PrinustabulaeformisCarr.)、白桦(BetulaplatyphyllaSuk.)和辽乐栎(QuercusliaotungensisKoidz.)的实测结果,说明了它的应用,并讨论了这3种典型群落呼吸量的差异。按以下4个步骤估算森林群呼吸量:(1)建立非同化器官的直  相似文献   

6.
Long-term heart rate fluctuations in postoperative and brain-dead patients were investigated. Heart rates were monitored continuously, and the data were stored, edited, and interpolated to allow for data lost during calibration and disconnection of the sensors for various treatments. Heart rate power spectra were calculated using the fast Fourier transform method. The power spectra of the patients who recovered showed that the heart rate fluctuated and produced a 1/f relationship, termed 1/f fluctuations, whereas those of patients who died in the intensive care unit (ICU) consisted of white-noise-like signals. The power spectra in brain-dead patients showed a 1/f relationship under steady-state conditions, while the power density and variation of the frequency distribution were lower than those in a normal subject. Therefore, 1/f fluctuations appear to be universal and occur independent of the central nervous system. (Chronobiology International, 15(6), 633-646, 1998)  相似文献   

7.
As heart-rate variability (HRV) is under evaluation in clinical applications, the authors sought to better define the interdependent impact of age, maximal exercise, and diurnal variation under physiologic conditions. The authors evaluated the diurnal changes in HRV 24-h pre- and post-maximal aerobic exercise testing to exhaustion in young (19–25 yrs, n?=?12) and middle-aged (40–55 yrs, n?=?12) adults. Subjects wore a portable 5-lead electrocardiogram holter for 48?h (24?h prior to and following a maximal aerobic capacity test). Time-, frequency-, time-frequency-, and scale-invariant-domain measures of HRV were computed from RR-interval data analyzed using a 5-min window size and a 2.5-min step size, resulting in a different set of outputs every 2.5?min. Results were averaged (mean?±?SE) over four prespecified time periods during the morning, afternoon, evening, and night on Day 1 and Day 2. Diurnal changes in HRV in young and middle-aged adults were compared using a two-way, repeated-measures analysis of variance (ANOVA). Young adults demonstrated higher HRV compared to middle-aged adults during periods of wakefulness and sleep prior to maximal exercise stress testing (i.e., high-frequency power during Day 1: young adults: morning 1862?±?496?ms2, afternoon 1797?±?384?ms2, evening 1908?±?431?ms2, and night 3202?±?728?ms2; middle-aged adults: morning 341?±?53?ms2, afternoon 405?±?68?ms2, evening 469?±?80?ms2, and night 836?±?136?ms2) (p < .05). Exercise resulted in reductions in HRV such that multiple measures of HRV were not significantly different between age groups during the afternoon and evening periods. All measures of HRV demonstrated between-group differences overnight on Day 2 (p < .05). Young adults are associated with higher baseline HRV during the daytime. Sleep increases variability equally and proportionally to daytime variability. Given the higher baseline awake HRV and equal rise in HRV during sleep, the change in HRV from sleep to morning with exercise is greater in younger subjects. These physiologic results have clinical significance in understanding the pathophysiology of altered variability in ill patients. (Author correspondence: )  相似文献   

8.
胡勇军  王长录  邹琼超  沈向前  王海昌 《生物磁学》2013,(30):5878-5880,5891
目的:研究冠心病合并脑梗死患者的心率变异性情况,和心律失常的发生率,分析它们的变化规律,为患者疾病的治疗及预后提供更好的治疗指导。方法:研究对象为2012年2月~2012年12月我院心内科及神经内科的患者,其中Ⅰ组:冠心病合并脑梗死患者40例、Ⅱ组:单纯冠心病患者40例、Ⅲ组:单纯脑梗死患者40例、以及Ⅳ组:健康成人50例,统计全部患24 h心率变异性及心律失常发生情况,并进行对比分析。结果:Ⅰ组患者的心率变异性和心律失常发生明显高于其它组患者,差异均具有统计学意义(P〈0.05)。且心率变异性时域参数下降,心律失常发生率升高。结论:冠心病合并脑梗死患者的心率变异性和心律失常发生率增高,为避免冠心病合并脑梗死的患者突然心律失常及猝死,应积极改变治疗措施。  相似文献   

9.
Resting heart rate variability can be an index of sympathetic or parasympathetic dominance, according to the frequency of the variability studied. Sympathetic dominance of this system has been linked to increased risk of cardiovascular disease (CVD). Similarly, rapid and dramatic increases in heart rate reactivity to a stressor task have also been suggested as indicating increased risk of CVD via atherogenesis. Although both of these variables have been related to the development of cardiovascular disease, and both may be related to increased sympathetic activity or parasympathetic withdrawal, most research studies have tended to focus on either variable independently of the other. In order to investigate whether these two indices of stressor reactivity were related in relatively young and healthy subjects, resting heart rate variability data were collected from 80 volunteers for 20 minutes. In addition, heart rate reactivity data were collected during a 2-minute mental arithmetic stressor, which has been previously shown to induce significant increases in heart rate. After classifying subjects according to whether their heart rate variability data were above or below the mean for their gender, heart rate reactivity data were examined via MANOVA to detect significant differences between subject groups. Females showed significant effects, and males showed nonsignificant trends, but these two sets of data were in different directions, suggesting that gender may be a confounding factor in the relationship between heart rate reactivity and heart rate variability.  相似文献   

10.
Recent studies have found a significant association between PTSD and low heart rate variability (HRV), a biomarker of autonomic dysregulation. Research indicates that respiratory sinus arrhythmia (RSA) biofeedback increases HRV while reducing related pathological symptoms. This controlled pilot study compared RSA biofeedback to progressive muscle relaxation (PMR) as adjunctive interventions for 38 persons with PTSD symptoms in a residential treatment facility for a substance use disorder. Both groups were assessed at pre-intervention and 4-week post-intervention. Group × time interactions revealed significantly greater reductions in depressive symptoms and increases in HRV indices for the RSA group. Both groups significantly reduced PTSD and insomnia symptoms and a statistical trend was observed for reduced substance craving for the RSA group. Increases in HRV were significantly associated with PTSD symptom reduction. Overall, these results provide preliminary support for the efficacy of RSA biofeedback in improving physiological and psychological health for individuals with PTSD.  相似文献   

11.
目的:研究互信息和自相关函数在睡眠各阶段心率变异性(heart rate variability,HRV)分析中的应用。方法:采用网络公开数据库SleepHeart Rateand Stroke VolumeDataBarhk,将RR序列分为30S一段,并以每30S数据为中心截取5minRR序列作为待分析对象。提取5minRR序列的互信息特征BDM、PDM和自相关函数特征BDC、PDC,然后用统计方法分析各特征在觉醒瓜EM/浅睡/深睡四种睡眠状态下的差异。结果:浅睡和深睡期间,BDM、PDM显著高于觉醒和REM睡眠(P〈0.001)。而BDC显著低于觉醒和REM睡眠(P〈0.001),PDC无显著差异(P〉0.05)。结论:①BDM、PDM和BDC从不同角度反映了不同睡眠阶段下RR序列的特征,它们或许与HRV不同的调节机制有关。@BDM、PDM和BDC可作为辅助HRV睡眠分期的新指标。  相似文献   

12.
目的:探讨急性心力衰竭(AHF)患者就诊时血压心率及血浆脑钠肽(BNP)水平与心功能的关系。方法:选取2013年4月-2014年12月于本院治疗的AHF患者134例,于就诊时测量患者血压、心率、BNP及心脏超声相关指标,分析血压心率及血浆BNP水平与心功能的关系。结果:就诊时SBP水平与左心室舒张末期直径及每搏输出量呈现正相关性(r=0.134、0.238,均P0.05);心率与每搏输出量、左室缩短率以及射血分数呈现负相关性(r=-0.177,-0.231,-0.197,均P0.05);BNP水平与左心室舒张末直径成正相关性,与左室缩短率以及射血分数呈负相关性(r=0.150、-0.247、-0.271,均P0.05)。结论:血压、心率以及BNP是临床诊断、评估AHF的重要指标。  相似文献   

13.
14.
The respiration rate of third stage larvae of Caenorhabditis sp. exposed to 0.53 × 10⁻² M EDB was 120% greater than in untreated checks and was highest shortly after the exposure began. Similarly-treated third- and fourth-stage Aphelenchus avenae exhibited no marked respiratory response. Different responses of these animals to EDB probably reflect basic physiological differences between the nematodes.  相似文献   

15.
目的:研究川崎病患儿的心率变异性指标与血清氨基末端脑钠肽前体(NT-pro BNP)及肌钙蛋白I(cTnI)水平的相关性,为临床诊疗提供依据。方法:选取2013年7月到2015年7月我院收治的川崎病患儿120例为研究组,根据患者是否存在冠状动脉损害分为A组(有冠状动脉损害)60例和B组(无冠状动脉损害)60例,同时选取同期健康体检儿童60例为对照组,比较各组窦性N-N间期标准差(SDNN)、5min N-N间期平均值标准差(SDANN)、极低频功率(VLF)、低频功率(LF)、高频功率(HF)、NT-proBNP水平以及cTnI水平。结果:研究组SDNN、SDANN、VLF、LF以及HF显著低于对照组,且A组显著低于B组,差异具有统计学意义(P0.05);研究组NT-proBNP水平和cTnI水平显著高于对照组,且A组显著高于B组,差异具有统计学意义(P0.05);研究组NT-proBNP与SDNN和HF呈负相关关系(P0.05),cTnI与SDNN和HF呈负相关关系(P0.05)。结论:心率变异性指标与川崎病患儿冠状动脉损害有关,与NT-proBNP、cTnI呈负相关关系。  相似文献   

16.
心率与血压的变异性:分析方法,生理意义及其应用   总被引:19,自引:0,他引:19  
本文回顾了关心回顾变异性及血压变异性的最新进展。在分析方法方面介绍了单一生理变量多变量系统的线性分析技术及其主要结果。对HRV/BPV谱的生理意义及其应用问题,也进行了回顾了评述。  相似文献   

17.
目的:探讨冠心病患者心率变异性(HRV)与冠状动脉病变狭窄范围及严重程度的关系。方法:选取上海市第十人民医院2015年1月至2018年7月期间收治的冠心病患者220例,所有患者均行冠脉造影及24 h动态心电图检查。按狭窄范围分为单支狭窄组(n=68)、双支狭窄组(n=82)、三支狭窄组(n=70),按狭窄严重程度分为轻度组(狭窄≤50%,n=62),中度组(50%狭窄70%,n=66),重度组(狭窄≥70%,n=92),另选取51例同期于我院体检的健康志愿者作为对照组。记录冠心病患者与对照组HRV各项指标,比较不同冠脉病变狭窄范围患者、不同狭窄严重程度患者正常平均N-N间期(SDNN)、正常相邻每5minR-R间期均数标准差(SDANN)、正常相邻正常N-N间期的均方根(RMSSD)、正常相邻间期差值高于50 ms心搏数占总心搏数的百分比(pNN50)、低频(LF)、高频(HF)及低频/高频比值(LF/HF)。结果:冠心病患者与对照组RMSSD、pNN50、LF、HF比较差异无统计学意义(P0.05),冠心病患者SDNN、SDANN低于对照组,LF/HF值高于对照组(P0.05)。不同冠脉狭窄范围、不同冠脉病变狭窄严重程度患者pNN50、LF、HF整体比较无统计学差异(P0.05),随着冠脉狭窄范围的增加或狭窄病变严重程度的加重SDDN、SDANN、RMSSD逐渐降低,LF/HF值逐渐升高(P0.05)。结论:HRV是评估心脏自主功能的良好指标,该指标中SDDN、SDANN、RMSSD、LF/HF值可作为评估冠心病患者冠状动脉的狭窄程度和狭窄范围的良好指标,具有重要的临床指导意义。  相似文献   

18.
Decreased vagal activity and increased sympathetic arousal have been proposed as major contributors to the increased risk of cardiovascular mortality in patients with depression. It was aim of the present study to assess the feasibility of using heart rate variability (HRV) biofeedback to treat moderate to severe depression. This was an open-label study in which 14 patients with different degrees of depression (13 f, 1 m) aged 30 years (18–47; median; range) and 12 healthy volunteers attended 6 sessions of HRV biofeedback over two weeks. Another 12 healthy subjects were observed under an active control condition. At follow up BDI was found significantly decreased (BDI 6; 2–20; median 25%–75% quartile) as compared to baseline conditions (BDI 22;15–29) in patients with depression. In addition, depressed patients had reduced anxiety, decreased heart rate and increased HRV after conduction of biofeedback (p < 0.05). By contrast, no changes were noted in healthy subjects receiving biofeedback nor in normal controls. In conclusion, HRV biofeedback appears to be a useful adjunct for the treatment of depression, associated with increases in HRV.  相似文献   

19.
目的:探讨原发性高血压患者心率变异性(HRV)及血压变异性(BPV)与血管损害的相关性。方法:选取2014年12月到2017年12月期间在我院接受治疗的原发性高血压患者94例,根据脉搏波传导速度(PWV)的不同分为对照组(60例)和血管受损组(34例)。比较两组患者的HRV、BPV指标,并分析PWV与HRV、BPV指标的相关性。结果:血管受损组的5 min心搏R-R间期平均值的标准差(SDANN)低于对照组,低频(LF)、高频(HF)、低高频之比(LF/HF)高于对照组,差异均有统计学意义(P0.05);血管受损组的24h平均收缩压(24h SBP)、24h平均脉压(24h PP)、白天平均收缩压(dSBP)、白天平均脉压(dPP)、夜间平均收缩压(nSBP)、夜间平均脉压(nPP)高于对照组,差异均有统计学意义(P0.05);PWV与LF、HF、LF/HF、24h SBP、24h PP、dSBP、dPP、nSBP、nPP均呈正相关(P0.05)。结论:原发性高血压患者部分HRV、BPV指标与PWV呈明显的相关性,说明HRV和BPV与患者的血管损害密切相关。  相似文献   

20.
Fourteen diurnally active (07: 00–22: 39 h) normotensive healthy control subjects and 14 kidney transplant patients were studied by ambulatory blood pressure monitoring and wrist actigraphy simultaneously during one 24-h period. In the control group, circadian rhythms in systolic (SBP), diastolic (DBP), and mean arterial (MAP) blood pressure, heart rate (HR), and wrist activity were documented by cosinor analysis with comparable afternoon peak times. In contrast, circadian rhythms with afternoon acrophases were detected only in HR and wrist activity in the patient group. The correlation of wrist activity with HR in controls and patients was comparable. Wrist activity and blood pressure were associated (r = 0.65 DBP and 0.54 SBP; p < 0.05) in controls, while in patients the relationship was weak or absent (r ranging from 0.02 SBP to 0.22 DBP). In 6 of 14 patients, BP and wrist activity were negatively correlated, reflecting the existence of nocturnal hypertension. In eight others, the correlation was small but positive. The 24-h pattern in BP and wrist activity in controls was comparably phased; however, this was not the case for the transplant patients, indicating the day-night pattern in blood pressure in this group is strongly dependent on pathologic phenomena rather than activity level and pattern.  相似文献   

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