血压降比例与年龄的联系

从上海112，419[1]人血压的分析中得出，人的收缩与舒张血压降的比例总是接近黄金数，血压降偏离黄金数的程度跟年龄和性别有关。人的一生，可分为收缩与舒张血压降比例不同的，三个年龄阶段，人到一定年龄，血压降和黄金数的偏差急速增大。     

心率与血压变异性

心率与血压变异性郑达安综述　蒋有铭　审校（上海医科大学生物医学工程教研室）早在十八世纪中叶，人们已开始注意到许多血流动力学参数如动脉血压、射血分数、心率等都呈现一定的周期性，它们在每一个心动周期中以一定的周期重复着，但并不是一个绝对的常数，它们在拍－...     

心率变异性研究进展

心率变异性指窦性心率的波动变化程度.其发生的主要机制是心脏节律直接受心交感和心述走神经的双重调节并相互制约.传统的心率变异性分析包括时域方法和频城方法,二类指标密切相关,非线性分析方法属近年来兴起的"新方法",目的在于描述RR间期的动态变化特征.心率变异性可用来预测心脏性猝死、评价心脏自主神经的活动性、均衡性有关的病理状态,因而具有重要临床价值.必须建立一种标准的测量分析方法,才能使心率变异性成为临床常规监测项目.     

阿托品对心率及心率变异性复杂度的影响

阿托品对人体中枢神经系统的影响可反映在心率和心率变异性的变化上,因此心率和心率变异性的特征参数变化与阿托品的作用过程之间存在必然的联系.实验采集了10个健康的志愿者在阿托品药物注射前后的心电信号,并有效地从心电信号中提取出了可供实验的心率变异信号,以心率和三阶复杂性测度为指标,对比药物注射前后指标的变化规律.结果表明,在阿托品药物注射后,样本的心率会上升到一个较高的水平,而心率变异信号的复杂度则会下降到一个很低的水平,然后缓慢恢复,大约在药物注射150 min后,指标恢复到药物注射前的水平,其变化规律在临床上可以用于对阿托品药物作用过程的监测.     

心率变异性的检测与分析

心率变异性(HRV)是逐次心跳R-R间期之间存在的微小差异,其蕴涵着心血管神经及体液调节的大量信息,心率变异性的检测与分析是近年来心电信号处理领域的研究热点,其对于心血管系统疾病的无创检测具有重要的临床意义。本文介绍了心率变异性的原理、研究现状与临床意义,描述了用于计算心率变异性的各种QRS复合波检测方法,综述了心率变异性的时域分析、频域分析、时频分析和非线性动力学分析方法,并总结展望了今后的研究方向。     

睡眠中的心率变异性

睡眠中的心率变异性杨军俞梦孙苏琳陈蓓北京新兴生物医学工程研究发展中心（１０００３７）睡眠医学与研究觉醒和睡眠好像一个钟摆，是生命活动必需的两个互相转化的过程。对睡眠过程的研究无疑对我们了解人体生理机制有重要意义，还可以发现某些疾病的隐患或者致病因素，...     

低氧与心率变异性研究进展

高原或运动等生理性低氧或/和临床心血管、呼吸及代谢等疾病病理性缺氧均可改变机体自主神经调节功能,从而导致心率变异性(HRV)变化。HRV对机体功能状态评定、多种疾病的诊断、预后及疗效评价具有重要价值。本综述简要介绍近年来有关低氧与HRV的研究进展。     

心率变异性分析方法的现状与展望

心率变异(HRV)蕴涵着心血管神经及体液调节的大量信息，心率变异性分析是近年来心电信号处理领域的研究热点，它对于相关疾病的无创检测具有重要的临床意义。本文系统阐述了HRV经典分析方法及其最新研究进展，并提出了今后的研究方向。     

心率变异性与抑郁关系的研究新进展

心率变异性（heart rate variability,HRV）是记录并分析连续心跳间期的变化,多与自主神经系统活动密切相关。近年来,心率变异性相关指标被应用于个体抑郁的检测和评估中。研究发现,抑郁患者的HRV时域和频域相关指标显著降低。HRV指标对于个体不同抑郁程度、抑郁类型和抑郁症状也具有一定的敏感性。HRV的降低也能够在一定程度预测其抑郁风险。心率变异性与抑郁的关联可能基于大脑-神经内分泌系统-植物神经功能的生理机制。下丘脑-垂体-肾上腺轴功能障碍和肾素-血管紧张素-醛固酮系统过度激活使抑郁患者交感神经活动过强。抑郁患者交感神经活动增强、副交感神经活动减弱,从而影响对心脏节律性的调节。抑郁还会减弱大脑中枢神经网络的整合功能,引起一系列HRV指标变化。这些指标在抑郁风险预测及抑郁干预效果评估中具有广泛的应用前景。     

静息心率与脑卒中关系的研究

静息心率与脑卒中相关危险因素,包括高血压、脂代谢异常、糖尿病、颈动脉粥样硬化性疾病等各方面均密切相关。机制在于交感神经过度激活,改变血压的昼夜节律、血流剪切力升高长期作用、颈动脉内-中膜的增厚相关、血管的内皮功能受损、各种炎症标志物、血管内斑块的形成等。治疗上,各大指南共识在原发疾病的基础上均确定了目标心率。β受体阻滞剂在降压治疗的同时可减慢心率,但要注意应个体化处理。静息心率是高血压患者预后的独立预测因子,降低静息心率可减少脑卒中的发生率及远期预后。     

EFFECTS OF DEPTH AND RATE OF BREATHING ON HEART RATE AND HEART RATE VARIABILITY

Effects of depth and rate of breathing on heart rate (HR) and HR variability were observed in two experiments. Respiration rate (RR) affected only cardiac stability, faster breathing producing more stable cardiac rate. Respiration depth (RD) affected both HR level and variability. Deep breathing produced faster, more variable HR, while shallow breathing had the opposite effects. A third experiment, in which Ss were trained to control HR using respiration, further illustrated the dramatic effects of respiration on cardiac rate. Implications of these results for experiments utilizing HR as a dependent variable and studies of autonomic control were discussed.     

HEART RATE ELUCTUATIONS AND FIXED FOREPERIOD REACTION TIME

Visual reaction times were recorded in a fixed foreperiod situation, to study the relation between sensorimotor performance and heart rate measures. With 42 male college students as Ss, both resting and performance levels of heart rate and heart rate fluctuations were obtained. Reaction time data were collected from blocks of trials at given foreperiods which ranged from 1 to 9 sec. Three groups of subjects, formed on the basis of high, medium, and low levels of peak-trough differences in heart rate during the reaction-time trials, showed different foreperiod functions. The hypothesis that fluctuations in heart rate are related to fixed foreperiod reaction time performance was supported.     

PACED RESPIRATION AND HEART RATE CONTROL

Five human subjects were presented with a high frequency tone on each short inter-heartbeat interval (IBI) and a low frequency tone on each long IBI. They were instructed to produce high tones in the presence of one visual stimulus and low tones in the presence of another under conditions of paced and unpaced respiration. The results indicated that control of heart rate is not dependent upon respiratory mediation.     

EFFECT OF INCREASES AND DECREASES IN BREATHING RATE ON HEART RATE AND FINGER PULSE VOLUME

Twenty per cent changes in breathing rate (increases and decreases), sustained for 10 min, do not change average heart rate; however, increases in breathing rate tend to decrease the standard deviation of heart rate and decreases in breathing rate tend to increase the standard deviation of heart rate. Neither increases nor decreases in breathing rate abolish sinus arrhythmia. Finger pulse volume is decreased by both increases and decreases in breathing rate. The standard deviation of finger pulse volume is decreased during slow-paced breathing and unchanged during fast-paced breathing. The decrease in finger pulse volume occurs within the first minute during slow-paced breathing; however, during fast-paced breathing the decrease does not occur until about 4 min after the onset of paced breathing.     

HEART RATE RESPONSE TO SOUND AND LIGHT

The heart rate (HR) response to five intensities of sound was examined in 18 subjects and to five intensities of light in 12 subjects. Each subject was tested on four occasions at monthly intervals. After covariance adjustment, significant acceleration to sound was found within the first 5 beats after stimulus onset but no significant deceleration occurred. There were no differences between testings. Individuals’ HR acceleration was reliable over testings and differing experimental contexts. No habituation occurred and no consistent relationship between HR response and ego strength was found. There was no significant HR response to light stimulation. The results were discussed in relation to Graham and Clifton's (1966) hypotheses concerning the relationship of the HR response to the orienting reflex (OR).     

STIMULUS DETECTION DURING PERIODS OF HIGH AND LOW HEART RATE

The study was designed to test Lacey's suggestion that elevated heart rate and blood pressure could lead to decreased sensory sensitivity and that a reduction in heart rate and blood pressure may facilitate sensory sensitivity. A tone of five intensities encompassing the subject's intensity threshold was presented randomly 25 times under high and 25 times under low transient heart rate. The results indicated no differences in the number of correct detections under high and low heart rate and no interaction between heart rate level and tone intensity. It was concluded that low heart rate may well be a necessary condition for increased sensory sensitivity, but that it is not a sufficient condition. Discussion was directed to the range of possible HR changes and the possible requirements of the sensitivity mechanism.     

OPERANT CONDITIONING OF HEART RATE SLOWING

The purpose of this study was to see if heart rate (HR) slowing could be operantly conditioned. Ten experimental Ss and five yoked-control Ss were studied. Experimental Ss were positively reinforced for slowing their HR on a beat-by-beat basis, whereas yoked-control Ss were reinforced in a pattern based on the performance of paired experimental Ss. The data showed that: some Ss can be taught to slow their HR by means of an operant conditioning procedure; Ss appear to learn better when they do not infer correctly what the response is that they are controlling; the conditioned HR response is apparently not mediated by changes in breathing; and reinforcement, per se, is not adequate to lower HR.     

一种适用于心率变异分析的R波检测与定位算法

在心率变异分析中,不仅要可靠地检测出 R 波,而且要对 R 波的峰值点进行准确定位。本文提出一种简单有效的 R 波检测方法,它不仅能够有效地抑制心率变异分析中的基线漂移、工频噪声、肌电、运动伪迹等干扰,提高实时检测 R 波准确率,并且能够对 R 波的峰值点准确定位。由于算法简单,适用于便携式心率变异分析仪。     

CEPHALIC VASOMOTOR AND HEART RATE MEASURES OE ORIENTING AND DEEENSIVE REELEXES

The problem of differentiating orienting (OR) and defensive reflexes (DR) was investigated by measurements of forehead-skin pulse amplitude (PA), forehead-skin blood content (BC), and heart rate (HR). Thirty male college students received 30 stimulations of .5 sec white noise at either 80 db or 120 db. Beat-by-beat analyses of the physiological measures indicated that both intensities of stimulation produced decreases in PA. Forehead BC showed larger increases to 120 db than to 80 db, and successive stimulations produced a change to overall decreases in BC at both intensities. HR acceleration occurred to both stimuli, and a short-latency deceleration occurred to 80 db. The results were interpreted as showing that cephalic vasoconstriction is the dominant response to auditory stimulation, and cephalic vasomotor responses do not differentiate between ORs and DRs. The short-latency HR deceleration and smaller HR acceleration differentiated the OR from the DR.