Lack of Correlation Between Cerebral Vasomotor Reactivity and Flow-Mediated Dilation in Subjects Without Vascular Disease

Cerebral vasomotor reactivity (CVR) represents the capability of cerebral vessels to modify their caliber in response to a stimulus. Impaired CVR is associated with an increased risk for ischemic events in patients with carotid disease. Endothelial dysfunction is considered an important pathogenic factor for atherosclerosis and can be noninvasively assessed by flow-mediated vasodilation (FMD) evaluation. We aimed to evaluate both CVR and FMD in patients without histories of vascular disease in order to define a possible correlation. FMD was measured as brachial artery flow and diameter changes induced by transient ischemia. CVR to hypercapnia was assessed in all subjects by means of a breath-holding test and, in 20 subjects, by an additional CO₂ inhalation test. In 30 healthy volunteers (60% women, mean age 56 ± 6 years), CVR and FMD did not appear to be correlated (p = 0.444). A strong association between CO₂-induced CVR and breath-holding index was observed (p < 0.001). CVR and FMD represent 2 different modalities that evaluate vasomotor function. According to our data, they did not appear to correlate, probably due to physiologic differences between cerebral and peripheral vascular districts and the vasodilatory stimulus used. The carbon dioxide-induced CVR and breath-holding index appeared to be significantly associated.     

正常人颈、股动脉内-中膜厚度及肱动脉内皮舒张功能临床研究

目的探讨正常人颈动脉(CA)、股动脉(FA)内中膜厚度(IMT)及肱动脉内皮依赖性舒张功能(EDD)的超声诊断标准。方法利用高频超声测量236例不同年龄组正常健康者CA、FA的IMT及肱动脉EDD。结果正常人CA的IMT均值为(0.59±0.12)mm,FA均值为(0.63±0.15)mm,CA、FA的IMT上限分别为0.83mm、0.93mm。EDD均值为(16.16±5.63)%。年龄≤50岁正常人CA、FA的IMT上限分别为0.7mm、0.77mm。年龄>50岁正常人CA、FA的IMT上限分别为0.98mm、1.07mm。结论正常人CA、FA的IMT变化规律表现为随年龄增长而增厚;肱动脉EDD随年龄增长而减低。关键词     

应用彩色多普勒超声评价肱动脉血管内皮功能的研究

目的　探讨彩色多普勒超声(CDFI)评价肱动脉血管内皮功能的临床应用及其意义。方法　对30例原发性高胆固醇血症(PHC)患者给予辛伐他汀(SVT)治疗8周,用CDFI测定治疗前后反应性充血时和含服硝酸甘油后肱动脉内径的变化。结果　PHC患者SVT治疗前反应性充血时肱动脉内径的扩张程度为338%±548%,与正常对照组(1758%±64%)相比在统计学上有显著性差异(P<0001)。SVT治疗8周后反应性充血时肱动脉内径的扩张程度为1468%±505%,与治疗前相比明显改善(P<0001)。结论　应用CDFI可以准确、简便、有效地评价肱动脉血管内皮功能,对早期发现及评估动脉粥样硬化的发生等具有一定的临床价值。     

原发性高胆固醇血症患者血管内皮功能的彩色多普勒超声研究

目的 :应用超声显像法探讨原发性高胆固醇血症患者的血管内皮功能。方法 :对 6 0例原发性高胆固醇血症患者 ,应用彩色多普勒超声测定反应性充血时和含服硝酸甘油后肱动脉内径的变化 ,并与正常对照组进行比较。结果 :原发性高胆固醇血症患者反应性充血时肱动脉内径的扩张程度为 ( 2 .2 7± 5 .39) % ,与正常对照组 ( 17.5 8±6 .4) %相比在统计学上有显著性差异 ( P<0 .0 0 1)。含服硝酸甘油后肱动脉内径的变化在两组间有显著性差异 ( P<0 .0 5 )。原发性高胆固醇血症患者的血管内皮功能与总胆固醇水平、低密度脂蛋白 ( L DL - C)水平均呈负相关关系 ( r=- 0 .6 0 19、- 0 .3919,P均 <0 .0 1)。结论 :1.彩色多普勒超声显像可做为简便易行的方法评价血管内皮的功能 ;2 .原发性高胆固醇血症患者的血管内皮功能明显受损 ,受损程度与血浆总胆固醇水平、L DL- C水平密切相关。     

早期高血压肱动脉血管内皮功能研究

目的：探讨早期高血压患者血管内皮功能变化。方法：应用高分辨率超声检测46例原发性早期高血压患者和46例正常对照者充血性反应和含服硝酸甘油后肱动脉内径和峰值流速变化。结果：早期高血压患者肱动脉充血性反应后内径和峰值流速的变化率明显低于对照组，而含服硝酸甘油后的变化率与正常对照组无显著差别。结论：早期高血压肱动脉内皮依赖性舒张功能减低，并可以被高分辨率超声检测。     

高频超声评价维持性血液透析患者肱动脉内皮功能

目的探讨维持性血液透析（MHD）患者有动静脉内瘘侧和无动静脉内瘘侧的肱动脉内皮舒张功能（EDD）间有无差异。 方法应用高分辨率超声诊断仪,对38例应用动静脉内瘘行MHD的患者,检测动静脉内瘘侧（AVF组）及非动静脉内瘘侧（NAVF组）肱动脉基础内径、反应性充血后内径的变化并计算EDD。 结果MHD患者中AVF组肱动脉EDD（5.21±1.84）%较NAVF组（7.33±3.43）%明显减低,差异显著（P〈0.001）;MHD患者AVF组肱动脉基础内径（5.90±1.04）mm较NAVF组（4.37±0.88）mm明显增宽（P〈0.001）。 结论MHD患者有动静脉内瘘侧EDD较无动静脉内瘘侧损害严重。     

高分辨率超声技术对冠心病血管内皮功能的评价

目的采用高分辨率超声技术评估冠心病患者肱动脉内皮功能受损情况.方法通过选择性冠状动脉造影确定冠心病组患者28例,非冠心病组26例,在冠状动脉造影前后24h内进行肱动脉超声检查,比较反应性充血和含服硝酸甘油后肱动脉内径和血流变化,并对冠心病易患因素做比较.结果冠心病组较非冠心病组肱动脉血流介导的血管扩张反应(FMD)显著减低(4.17%±2.98%)vs(10.26%±8.41%),P=0.03,但两组含服硝酸甘油后血管内径无明显差异.两组的冠心病易患因子数(P=0.01)和吸烟(P=0.004)有显著性差异.结论应用高分辨率超声技术可非侵入性评价周围血管内皮功能,冠心病患者通常存在肱动脉FMD受损.此技术可作为一种无创性冠状动脉内皮功能检测方法.     

20-MHz Ultrasound for Measurements of Flow-Mediated Dilation and Shear Rate in the Radial Artery

A high-frequency scanning system consisting of a 20-MHz linear array transducer combined with a 20-MHz pulsed Doppler probe was introduced to evaluate the degree of radial artery flow-mediated dilation (FMD [%]) in two groups of patients after 5?min of controlled forearm ischemia followed by reactive hyperemia. In group I, comprising 27 healthy volunteers, FMD (mean?±?standard deviation) was 15.26?±?4.90% (95% confidence interval [CI]: 13.32%–17.20%); in group II, comprising 17 patients with chronic coronary artery disease, FMD was significantly less at 4.53?±?4.11% (95% CI: 2.42%–6.64%). Specifically, the ratio FMD/SR (mean?±?standard deviation), was equal to 5.36?×?10^?4?±?4.64?×?10^?4 (95% CI: 3.54?×?10^?4 to 7.18?×?10^?4) in group I and 1.38?×?10^?4?±?0.89?×?10^?4 (95% CI: 0.70?×?10^?4 to 2.06?×?10^?4) in group II. Statistically significant differences between the two groups were confirmed by a Wilcoxon–Mann–Whitney test for both FMD and FMD/SR (p?<0.01). Areas under receiver operating characteristic curves for FMD and FMD/SR were greater than 0.9. The results confirm the usefulness of the proposed measurements of radial artery FMD and SR in differentiation of normal patients from those with chronic coronary artery disease.     

系统性红斑狼疮患者颈动脉内-中膜厚度与肱动脉血管内皮舒张功能的超声研究

目的 利用高频超声检查系统性红斑狼疮(systemic lupus erythematosus,SLE)患者颈动脉内-中膜厚度(intima-medial thickness,IMT)及肱动脉血管内皮舒张功能,对SLE患者中亚临床动脉粥样硬化病变进行评估.方法 超声检查36例SLE患者(绝经前妇女,SLE病程1年以上)和36例正常对照组颈动脉IMT及肱动脉内皮依赖性(endothelium-dependent dilation,EDD)及非内皮依赖性(endothelium-independent dilation,EID)舒张功能,并进行对比分析.结果 SLE患者颈动脉IMT与对照组之间的差异具有显著性意义,SLE组肱动脉内皮依赖性及非内皮依赖性舒张功能,EDD/EID与正常对照组对比差异显著.结论 超声检查SLE患者颈动脉IMT及肱动脉内皮舒张功能可作为预测心血管事件的早期手段.     

长期服用缬沙坦对高血压患者颈动脉内膜-中层厚度及血管内皮依赖性舒张功能的影响

目的探讨缬沙坦对高血压患者粥样硬化动脉形态及功能的影响。方法以彩色多普勒超声检测83例高血压病患者颈动脉内膜-中层厚度（IMT），并按照IMT大小将83例患者分为3组，连续服用缬沙坦36个月后检测颈动脉IMT和未受干预状态下、肱动脉反应性充血时以及含服硝酸甘油后颈动脉内径，与治疗前进行比较。结果使用缬沙坦8周后血压能控制在140／90mmHg以下且保持平稳。治疗前A、B、C三组的颈动脉IMT值分别为（1．04±0．07）mm、（1．23±0．05）mm、（1．33±0．03）mm，治疗36个月后，三组的颈动脉IMT分别为（0．95±0．04）mm、（1．08±0．11）mm、（1．19±0．21）mm，各组治疗前后比较，P均〈0．01，A组IMT恢复达正常，B组IMT值接近正常。A、B、C三组治疗前肱动脉反应性充血时颈动脉内径的变化率分别为（6．87±2．23）％、（6．13±2．11）％、（5.88±1．26）％，治疗后分别为（24．71±7．02）％、（20，57±4．72）％、（14．32±3．81）％，各组治疗前后比较，P均〈0．01，A组疗效优于B组（P〈0．05）、C组（P〈0．01），B组疗效优于C组（P〈0．01），含服硝酸甘油后颈动脉内径在治疗前后无显著变化。结论血管紧张素Ⅱ受体桔抗剂缬沙坦在平稳降压的同时，能保护血管内皮细胞，改善血管内皮依赖性舒张功能，延缓甚至逆转IMT的进展。     

高频超声评价系统性红斑狼疮患者肱动脉内皮功能

目的应用高频超声测量系统性红斑狼疮(SLE)患者反应性充血前后肱动脉内径的百分变化率评价肱动脉内皮功能。方法研究对象包括36例系统性红斑狼疮患者(依病程分为SLE1组、SLE2组)和18例健康对照者。应用高频超声测量静息状态下、反应性充血后、舌下含服硝酸甘油后的肱动脉内径,并计算反应性充血和硝酸甘油诱发的内径百分变化率及二者之比。结果SLE1组反应性充血诱发的肱动脉内径百分变化率显著低于对照组(P<0.05);SLE2组反应性充血诱发的肱动脉内径百分变化率显著低于对照组(P<0.001);SLE2组反应性充血诱发的肱动脉内径百分变化率显著低于SLE1组(P<0.05)。SLE2组含服硝酸甘油后的肱动脉内径百分变化率显著低于对照组(P<0.05)。SLE1组EDV/EIV显著低于对照组(P=0.001);SLE2组内皮依赖性舒张(EDV)与非内皮依赖性舒张(EIV)之比(EDV/EIV)显著低于对照组(P<0.001);SLE2组EDV/EIV显著低于SLE1组(P<0.05)。结论系统性红斑狼疮患者肱动脉内皮功能减低,EIV功能亦会发生改变。EDV与EIV之比(EDV/EIV)比单纯的用反应性充血诱发的肱动脉内径百分变化率更能反映其内皮功能状态。     

高频超声评价急性心肌梗死患者肱动脉内皮功能

目的应用高频超声检测急性心肌梗死（AMI）患者反应性充血前后肱动脉内径扩张百分率评价肱动脉内皮功能。 方法对27例病程6周的AMI患者（根据超声心动图分为重构组和非重构组）和20例正常人应用高频超声测量静息状态、反应性充血后及舌下含硝酸甘油后肱动脉内径，计算反应性充血和硝酸甘油诱发的肱动脉内径扩张百分率。 结果重构组和非重构组反应性充血诱发的肱动脉内径扩张百分率均低于对照组（P〈0．01）；重构组反应性充血诱发的肱动脉内径扩张百分率低于非重构组（P〈0．05）；重构组和非重构组间及两组与对照组间含硝酸甘油后的肱动脉内径扩张百分率均无差异（P〉0．05）。 结论AMI患者肱动脉内皮依赖性舒张功能减低，AMI后早期左室重构与内皮功能障碍有关。     

中老年脑梗死患者颈动脉内膜-中层厚度及肱动脉内皮依赖性舒张功能的探讨

目的探讨中老年脑梗死与颈动脉粥样硬化、肱动脉内皮依赖性舒张功能的相关性及临床意义。 方法选择中老年脑梗死患者30例、健康志愿者61例，采用无创高分辨率超声诊断仪检测肱动脉在静息、反应性充血后血管舒张未期内径的变化以及对颈总动脉内膜中层厚度（intima-media thickness of the carotid artery IMTc）进行测定。 结果本研究显示中老年脑梗死组的肱动脉内皮依赖性舒张（Brachial arterial flow—mediated dilation FMDb）功能显著低于健康对照组（P＜0．01），IMTc明显大于健康对照组（P＜0．05），健康组和脑梗死组的IMT与FMD均呈显著负相关（r=-0．835，P＜0．01和r=0．419，P＜0．05）。 结论肱动脉内皮功能障碍与动脉粥样硬化显著相关，中老年脑梗死患者存在较严重的FMDb减低及1MTc增厚，FMDb及1MTc的测定对中老年脑梗死的预警和防治具有重要意义。     

Correlations Between the Localization of Accessory Atrioventricular Pathway and Doppler Indices of Left Ventricular Output and Function in Patients With Wolff-Parkinson-White Syndrome

Left ventricular (LV) output and function was investigated, using pulsed Doppler echocardiography in 52 patients with various localizations of accessory AV pathway (AP) in sinus rhythm and during paroxysm of AV reentrant tachycardia. In patients with sinus rhythm and ventricular preexcitation the most marked decrease in LV output and function (reduced aortic flow peak velocity [PV], mean acceleration [MA], stroke distance [SD], minute distance [MD], and lengthened time to peak velocity [TTP]) was noted in the presence of right parietal AP and less marked changes (decreased MA, lengthened TTP)--in the presence of posteroseptal AP, in comparison with the controls (P less than 0.005). During antidromic tachycardia the pronounced decrease in PV, MA, SD, and MD was noted, especially in patients with left parietal and posteroseptal AP, while in the case of right parietal AP changes in MA and MD were insignificant. During orthodromic tachycardia the decrease in LV function was less marked and no significant differences in the magnitude of LV output and function changes were found in various localizations of AP, except MA, which was more severely decreased in patients with posteroseptal AP. We conclude, that the alterations in Doppler indices of LV output and function are related to the localization of AP during AV reentrant tachycardia and regular sinus rhythm.     

TCD对头晕或眩晕患者脑血管病变的分析

目的分析神经科门诊头晕或眩晕患者颅内外血管狭窄发生频率,以及狭窄血管的分布情况,探讨导致头晕或眩晕的动脉狭窄原因。方法对2001年1月~2001年12月神经科门诊筛选主诉为头晕或眩晕,且无其他神经系统局灶体征者1676例。应用经颅多普勒超声(TCD)检测颅内Willis环及颅外颈部血管。结果(1)202例有脑血管的狭窄,血管狭窄的发生率为202/1676(12.10%)。其中,单纯颈动脉系统血管病变的发生率45.05%,高于单纯椎基底动脉系统32.18%(P<0.01);(2)椎动脉狭窄者占11.88%,其中,单侧椎动脉病变占79.167%,左右无明显差别;3.锁骨下动脉狭窄者占32.673%,其中伴盗血综合征者为28.79%。结论临床上不能仅仅简单的把单纯头晕或眩晕患者诊断为功能性疾病或椎基底动脉供血不足。     

Doppler myocardial imaging in the assessment of normal and ischemic myocardial function--past, present and future

Myocardial ischemia is associated with impaired regional myocardial function. Echocardiography is a suitable technique for the assessment of regional myocardial function as it is easily applicable and commonly available. However, most of the currently used echo-techniques are based on 2D images or M-mode traces. Therefore, they are limited either to the assessment of myocardial segments that can be insonated at 90° or are based on visually assessed wall motion scoring which is semiquantitative at best. Doppler myocardial imaging (DMI) is a new ultrasound technique which assesses the velocity of myocardial motion. Different parameters can be derived from this velocity information such as velocity time integrals, intramural velocity gradients and strain/strain-rate information. Moreover, DMI provides information of the timing of regional motion related to myocardial contraction and relaxation. These parameters are all assessed quantitatively, therefore, DMI is a promising technique to quantify myocardial function, avoiding the disadvantages of observer-dependant judgement of myocardial contraction.     

冠心病患者颈动脉内径及血流参数的多普勒超声测定

对１０３例经选择性冠状动脉造影的患者作双侧颈动脉多普勒超声检查。探讨多普勒超声检查颈动脉内径及血流参数的方法学以及正常颈动脉的多普勒频谱特征。分析不同冠脉病变组颈动脉内径及血流参数的差异，提出颈内动脉和颈总动脉血流速度的比值有助于检出轻度颈动脉粥样硬化性狭窄。     

Disturbed Endothelial Function of the Internal Thoracic Artery in Patients with Coronary Artery Disease

Objectives and Background The internal thoracic artery is an established arterial graft for myocardial revascularization. It never had been investigated, whether there are functional differences in this vessel between patients with or without coronary artery disease. Methods We investigated the left internal thoracic artery of 28 patients (15 with and 13 without coronary artery disease) with a duplex-system at rest and with a handgrip exercise. Results Concerning the measured flow velocities at rest there was only a significant difference between the diastolic mean and peak velocity between the two groups, the other investigated parameters demonstrate no significant difference. The peak diastolic and the mean diastolic velocity was less in patients with coronary artery disease during the handgrip-test. The flow reserve was decreased in patients with coronary artery disease (12.6±24.0% vs. 32.3±30.9%, P < 0.05). Conclusions We demonstrated, that patients with coronary artery disease have a higher peripheral resistance and a lower diastolic velocity of the internal thoracic artery during stress testing. This corresponds to a disturbed vasomotion and may be an early marker of arteriosclerosis.