右冠状动脉阻塞时交感神经对房室传导调节功能的实验研究

目的 研究右冠状动脉阻塞时交感神经对房室传导调节功能的影响. 方法 在去自主传出神经的动物上,结扎右冠状动脉造成急性下壁心肌梗死(AIMI)的动物模型,通过模板匹配的方法检测His束的A、H、V波,自动检测两心房波(AA)间期,心房波与His渡(AH)间期,并刺激双侧交感神经. 结果 正常动物刺激交感神经使得AH问期在未起搏与起搏时减少(14±5)%和(23±7)%;而心肌梗死时,刺激交感神经使AH间期在未起搏与起搏时减少(7±5)%和(12±2)%.后者只有前者减少幅度的50%和48%(P<0.05). 结论 在AIMI时,交感神经对心脏传导调节功能减弱,这种减弱可能参与AIMI伴房室传导阻滞发生的机制.     

交感神经系统在心力衰竭中的作用

<正>对于充血性心力衰竭(CHF)的研究随着病理生理学、分子生物学技术的开发及应用,已逐步从器官水平深入到细胞水平甚至基因水平,并确立了神经内分泌系统的主导作用,其中交感神经系统的作用举足轻重,大量研究证实其与CH病死率密切相关。长期应用β-受体阻滞剂不但可减轻心力衰竭症状,更重要的是可改善心衰患者的临床预后,降低病死率、再住院率。本文从生理、病理生理等方面对交感神经系统在心力衰竭(简     

交感神经活性对血液透析患者高血压的作用

目的研究以血浆肾上腺素和去甲肾上腺素为代表的交感神经系统在血液透析患者高血压发病中的作用.方法选取12例血液透析高血压患者,6例男性、6例女性,年龄30～60岁,作为高血压组.12例血压正常的血液透析患者,作为对照组.每例患者分别于透析前后采集血液标本检测血浆肾上腺素和去甲肾上腺素含量.同时记录每例患者透析前后平均动脉压(MAP).结果高血压组的平均动脉压透析前后无改变.高血压组的血浆去甲肾上腺素水平高于对照组,血液透析后无明显变化.血浆肾上腺素-去甲肾上腺素水平与MAP或透析间期体重增加无相关关系.结论以儿茶酚胺含量变化表示的交感神经活性参于血液透析患者的高血压的发生.     

化学性腰交感神经节切除的应用解剖研究

在４９具成人尸体标本中，解剖了腰交感神经节及其周边解剖结构，在腰２￣３椎体范围内内，应用“神经节记分”方法，测定了神经节大小、数量和分布情况。结果显示，双侧的第二腰交感神经节多在腰２椎体的１／３跨过椎间盘至腰２椎体上的１／３。同时还测量了腰动脉与交感链的相交点，腰交感链与主动脉、下腔静脉的距离等。该组资料为施行化学性腰交感神经节切除的临床应用提供了解剖理论依据。     

抑郁症患者交感神经皮肤反应的研究

目的研究抑郁症首次发病患者交感神经皮肤反应（SSR）的变化特点及其对抗抑郁治疗效果的评估作用。 方法选择50例符合国际疾病分类第10版（ICD-10）诊断标准的初诊抑郁症患者，作为抑郁症组，接受6周抗抑郁药物治疗。同时选择50例健康检查者作为对照组。治疗前、后检测SSR的潜伏期和波幅；根据正负相波波幅的高低将SSR波形分为P、N、M三型。 结果①50例抑郁症患者中，5例未引出SSR波形，45例引出SSR波形，其中P型7例（15.56%）、N型21例（46.67%）、M型17例（37.78%）。②抑郁症组与对照组比较，SSR潜伏期延长，波幅减低（P<0.01）；N型较P型潜伏期长、波幅低。抑郁症患者SSR波形分布与年龄、病程、汉密尔顿抑郁量表(HAMD)评分无明显相关性。③抗抑郁药物治疗有效的15例患者治疗后SSR潜伏期明显缩短、波幅增高，但与对照组相比，SSR潜伏期仍然明显延长。 结论抑郁症患者皮肤交感神经兴奋性减低，SSR波形中N型最为常见，N型较P型潜伏期长、波幅低。SSR可作为评估抗抑郁治疗效果的一项敏感、易行的神经电生理学检查指标。     

颈交感神经阻断后脑瘫大鼠上肢肌电图的研究

为在肌电图上观察交感神经阻事痉挛性脑瘫大鼠肢体痉挛状态的改善情况,将３０只大白鼠做成骈挛性脑瘫模型,分成３组,随机选择１组采用颈总动脉周围交感神经网剥脱切除术,另１组采用颈上节交感神经切断术,于术后第８ｄ用ＤＡＮＴＥＣ肌电图仪测量３组大鼠上肢肱三头肌的Ｆ波。     

缬沙坦对大鼠急性心肌梗死后交感神经重构的抑制作用

目的：探讨大鼠心肌梗死后交感神经重构现象以及缬沙坦对重构的抑制作用。方法：48只雄性Wistar大鼠随机分为两组，分别为心肌梗死组和心肌梗死后缬沙坦治疗组．心肌梗死组和心肌梗死后缬沙坦治疗组分别在3个不同的时间点（3、7、30d）进行观测，心肌梗死后缬沙坦治疗组按照5mg／（kg·d）的剂量灌胃。另外一组开胸后只芽线不结扎作为对照组。用Power Lab测定各组大鼠心电图，连续记录大鼠心电图，并对心律失常进行评分。用免疫组化的方法检测各组大鼠心肌梗死周边区交感神经密度。结果：心肌梗死组7、30d时免疫组化显示梗死周边区交感神经明显增生，与对照组相比差异有显著性（P〈0．05）。心肌梗死后缬沙坦治疗组在7、30d时，梗死周边区交感神经密度显著低于同时间点的心肌梗死组（P〈0．05）。心肌梗死后缬沙坦治疗组各个时间点的心律失常评分均较心肌梗死组相应时间点显著降低（P〈0．05）。结论：缬沙坦能抑制心肌梗死后交感神经增生和重构．并降低心肌梗死后心律失常的发生。缬沙坦降低心律失常的作用部分是通过抑制交感神经增生和重构介导的。[著者文摘]     

高脂血症对大鼠心肌梗死后交感神经重构的影响及机制探讨

目的:探讨高脂血症对大鼠心肌梗死后交感神经重构的影响.方法:32只SD大鼠随机分为A组(假手术组)、B组(高脂血症组)、C组(心梗组)和D组(心梗合并高脂血症组).免疫组化法检测梗死周边区生长相关蛋白-43(GAP-43)和酪氨酸羟化酶(TH)阳性神经纤维分布和密度.Western blot方法检测神经生长因子(NGF)和白介素-1β(IL-1β)蛋白表达.生化法检测氧化应激相关指标.结果:心肌梗死和高脂血症均可导致梗死周边区域GAP-43和TH阳性神经纤维密度显著增加(均P<0.05),并伴随着NGF、IL-1β蛋白表达的上调和氧化应激水平的增高,且两因素间存在交互作用(均P<0.05).GAP-43和TH阳性神经纤维密度与NGF、IL-1β蛋白水平及氧化应激呈良好的正相关性(均P<0.05).结论:高脂血症可以加剧心肌梗死大鼠交感神经重构,其机制与氧化应激和IL-1β释放增加导致NGF表达上调相关.     

应用交感神经皮肤电反应评估30例糖尿病患者的交感神经功能

目的观察交感神经皮肤电反应对糖尿病患者交感神经功能的敏感性,并与健康人进行对比与分析。方法选择2004-10/2005-03哈尔滨医科大学附属第四医院收治的2型糖尿病患者30例,应用KEYPOINT4000型诱发电位仪记录交感神经皮肤电反应的潜伏期和波幅,并与50名正常对照组进行对比分析。结果80例受试者全部进入结果分析。①潜伏期:糖尿病组长于正常对照组[上肢:(1.79±0.38),(1.44±0.09)ms;下肢:(2.59±0.38),(2.09±0.18)ms;P<0.01]。②波幅:无论上下肢,糖尿病组和正常对照组比较差异不显著(P>0.05)。③糖尿病组交感神经皮肤电反应异常率为40%(12/30),明显高于临床症状体征阳性率20%(6/30)。结论①糖尿病患者的交感神经皮肤电反应的潜伏期延长。②交感神经皮肤电反应对糖尿病患者交感神经亚临床病变有一定的敏感性。     

血容量减少时动脉压力感受性反射的仿真研究

目的 建立心血管系统计算机数学模型，对颈动脉窦压力感受性反射进行数字仿真。方法利用包含多种心血管反射的血流动力学模型，采用ODE45可变步长算法模拟急性失血。结果动脉压力感受性反射处于低值运行或是在高值运行时，静脉非压力容积对心输出量和总外周阻力起了重要的调节作用。结论仿真模型可以作为动物实验的预研手段。     

急性失血对心脏功能的动态模拟

目的在急性失血条件下,用计算机仿真方法评价心脏功能的变化。方法利用包含多种心血管反射的血流动力学模型,采用ODE45可变步长算法模拟急性失血。结果失血后主动脉压力、输出量和每搏输出量均减少。在血容量减少时, 静脉非压力容积与血管阻力相比,对重建稳态起了更重要的调控作用。结论仿真模型可以作为动物实验的预研手段。     

颈动脉窦压力感受性反射的数字仿真实验

目的：建立心血管系统数学模型，对动脉窦压力感受性反射进行数字仿真。方法：采用MATLAB／SIMULINK系统软件，建立整体心血管系统模型，并作大鼠的孤立窦实验。结果：仿真实验和动物实验所得到的压力反射曲线具有良好的一致性。结论：仿真模型具有可扩充性，可以作为动物实验的辅助工具。     

The Site of Sympathetic Deficit in Cluster Headache

The pattern of autonomic deficit in the face of cluster headache patients resembles the deficit in patients with a postganglionic sympathetic lesion from some other cause; however the presence of abnormal cardiac rhythms and bilateral pupillary reflex deficit in some patients with cluster headache suggests that the lesion might compromise central sympathetic drive. To investigate this possibility, the vasomotor and sudomotor startle reflex was investigated in the hands of sic cluster headache patients with ocular and thermoregulator signs of postganglionic sympathetic deficit in the face; for comparison, responses were also investigated in 15 patients with a lesion in the cervical sympathetic pathway from some other cause. The startle reflex was intact in the hands of the six cluster headache patients, but was diminished ipsilaterally in patients with a central or preganglionic sympathetic lesion and also, surprisingly, in patients with a postganglionic lesion caused by an aneurysm of the internal carotid artery. Ocular sympathetic deficit was greater in patients with an aneurysm of the internal carotid artery than in cluster headache patients or in patients with a postganglionic sympathetic lesion from some other cause; the aneurysm may have compromised neurons with projections to the face and hand, or could have induced transsynaptic degeneration of preganglionic fibers supplying both regions. The findings indicate that central sympathetic drive is not impaired in cluster headache patients; thus, a peripheral lesion probably induces sympathetic deficit on the symptomatic side of the face.     

Sympathetic activation during the cold pressor test: influence of stimulus area

Summary. The purpose of this study was to determine the effect of the size of the stimulus area on the muscle sympathetic nerve activity (MSNA), systolic arterial blood pressure (SAP), and heart rate responses to the cold pressor test. To accomplish this, these variables were measured before (control), during, and after 1·5 min of ice water immersion of either one or both hands in nine healthy subjects (aged 19–27 years). The cold stimulus elicited significant increases above control levels in all three variables under both conditions (P<0·05). Immersion of both hands produced a much greater increase in total MSNA (+366%) than immersion of a single hand (+187%) (P<0·05). However, the magnitudes of the increases in SAP and heart rate during two-hand immersion (29±6 mmHg and 10±2 beats min^-1) were not significantly different from the responses during the one-hand trials (24±5 mmHg and 6±2 beats min^-1, P>0·05). There was a strong, direct relationship between total MSNA and SAP responses during one-hand immersion (r= 0·93, P<0·001) but not during immersion of both hands (r= 0·66, P= 0·08). These findings indicate that during the cold pressor test the magnitude of the increase in sympathetic discharge to skeletal muscle, but not the systolic blood pressure response, is influenced by the size of the tissue area exposed to the stimulus.     

Design and Rationale of a Real-Life Study to Compare Treatment Strategies for Cardiovascular Risk Factors: The CRUCIAL Study

Abstract

The CRUCIAL trial was designed to compare the relative reduction in calculated Framingham coronary heart disease risk when a multiple risk factor intervention strategy, based on single-pill amlodipine besylate/atorvastatin calcium, was compared with a usual-care strategy. Eligible patients had treated or untreated hypertension, ≥ 3 additional cardiovascular risk factors, and baseline total cholesterol ≤ 6.5 mmol/L, but no coronary heart disease. The CRUCIAL trial was a 12-month, international, multicenter, prospective, stratified, cluster-randomized, parallel-design, open-label trial conducted in 20 countries in Asia, the Middle East, Europe, and Latin America. We anticipate the results of this study will be available in mid to late 2010. In this article we report the rationale for and design of the CRUCIAL trial and discuss how the challenges in the design and conduct of this cluster-randomized trial were addressed. The cluster-randomized trial design, with the investigator as the unit of randomization, was chosen to minimize contamination between the trial arms. The intent of the study was to compare the new therapeutic strategy with customary treatment practices, so no recommendation was made regarding the choice of antihypertensive or lipid-lowering drugs in the usual-care arm. It was considered that if the investigator managed both arms of the trial it would be difficult to prevent crossover of treatment strategies. Patients were enrolled in the study before the investigators were randomized to avoid selection bias. Investigators were randomized in a 1:1 ratio within each country to explicitly balance the treatment arms with respect to potential confounding factors. The cluster effect was taken into account in the sample size calculation. The findings from the CRUCIAL trial have the potential to inform current thinking on how to effectively reduce the cardiovascular risk of patients with hypertension and additional risk factors but only modestly elevated total cholesterol.     

The Enhanced Ciliospinal Reflex in Asymptomatic Patients With Cluster Headache is Due to Preganglionic Sympathetic Mechanisms

An amplified ciliospinal reflex response has been documented in patients with cluster headache, lacking a Horner like syndrome. The mechanism is unknown, Tentatively, it may be due to an increased release of monoamines from post-ganglionic sympathetic nerve endings or an increased density of postsynaptic adrenergic receptors in the dilatator muscle of the iris.
The instillation of a 1% phenylephrine solution into the conjunctival sac induces mydriasis by stimulating postsynaptic adrenergic receptors in the dilatator muscle of the iris, while the instillation of a 2% tyramine solution causes mydriasis by releasing noradrenaline from the presynaptic sympathetic nerve terminals in the iris.
According to these premises, a positive correlation shouId be expected between the ciliospinal reflex response and the pupillary response to tyramine, if the enhanced ciliospinal so-flex response was due to an increased presynaptic release of monoamines. No such correlation was found. Nor was there any positive correlation between the ciliospinal reflex response and the pupillary response to phenylephrine, contradicting an increased density of postsynaptic monoaminergic receptors in the dilatator muscle of the iris as the explanation. However, there was a significant positive correlation between the pupillary responses to phenylephrine and tyramine, ruling out any functionally caused "denervation" hypersensitivity in the dilatator muscle of the iris.
It is concluded that the amplified ciliospinal reflex response in cluster headache patients (lacking a Horner-like syndrome) reflects compensatory pathophysiological mechanisms proximal to the third-order sympathetic neuron.     

Cardiovascular simulation using a multiple modeling method on a digital computer—Simulation of interaction between the cardiovascular system and angiotensin II

A cardiovascular system model that simulates interactive responses to drugs has been developed on a small digital computer. The overall model basically consists of three models. The first is a momentum transport model that represents relations between blood pressure and flow in the cardiovascular system. In this model, the cardiovascular system is divided into 14 components and modeled by using equivalent electrical circuits. The second is a mass transport model comprising 14 compartments corresponding to the respective components of the cardiovascular system. This model represents the distribution of the administered drug in the various cardiovascular components. The third is an interaction model that represents the relationships between the momentum and mass transport models. This model causes variations in the resistance and capacitance parameters of the momentum transport model as a function of the current drug concentrations in the appropriate compartments of the mass transport model. The capacitances representing the ventricles are varied in a time-dependent fashion to simulate the beat of the heart. Simulation is performed by using the Euler method to solve a system of 28 ordinary differential equations governing the momentum and mass transport models on a 32-bit microcomputer, a Macintosh II. The model was assessed by performing two demonstrations of the cardiovascular response to the vasopressor angiotensin II (AT II). They first examined the interaction between the cardiovascular system and AT II. The effect of AT II on the cardiovascular system was incorporated into the interaction model. Administration of AT II as a constant infusion (200 µg/hr) resulted in an elevation of mean arterial pressure from approximately 100 to 150 mm Hg. The second was a pharmacodynamic demonstration of the cardiovascular system in the presence of tumor tissue during induced-hypertension chemotherapy. A tumor tissue component was added to the cardiovascular system model, thereby incorporating into the interaction model the effects of blood pressure elevation on tumor tissue. The same administration of AT II as above resulted in an increase in blood flow from 0.3 and 1.3 ml/s (i.e., an increase of approximately 460%) in the carcinomatous tissue. The results, along with those obtained earlier with sodium nitroprusside, indicate that the present simulator could represent the cardiovascular system during administration of vasoactive drugs.     

Variation Analysis of Sphygmogram to Assess Cardiovascular System under Meditation

In this article, we studied how meditation affects the characteristics of the cardiovascular system, mainly based on blood pressure waveforms (BPW). Four parameters derived from BPW include the rising slope (h(1)/t(1)), normalized height of T wave (h(3)/h(1)), normalized height of V(3) valley (h(4)/h(1)) and normalized height of D wave (h(5)/h(1)), where t(1) and h(i), i = 1, ... ,5 are quantitative features of the BPW waveform pattern. A larger value of h(1)/t(1) reflects better heart ejection ability and aorta compliance. A larger value of h(3)/h(1) may infer an arterial system with good elasticity. The decrease (increase) of h(4)/h(1) parameter indicates the decrease (increase) of peripheral resistance of vessels. A larger value of h(5)/h(1) indicates better artery elasticity and aortic valve function. In comparison with the control group, Zen-meditation practitioners have more after-meditation h(1)/t(1), h(3)/h(1) and h(5)/h(1) increase, with more h(4)/h(1) decrease, with statistical significance (P < 0.05). The observation allows us to infer that Zen meditation may effectively improve relevant characteristics of the cardiovascular system.     

Preoperative Low-dose and High-dose Pregabalin and Cardiovascular Response to Endotracheal Intubation: A Prospective,Randomized, Single-blind,Controlled Study in China

Purpose

A prospective, randomized, single-blind, controlled clinical study was designed to evaluate the efficacy and tolerability of preoperative pregabalin on cardiovascular response to laryngoscopy and endotracheal intubation.