Assessment of Coronary Flow Velocity Reserve by Noninvasive Transthoracic Doppler Echocardiography in Patients with Angiographically Normal Coronary Arteries

Angiographically normal coronary arteries cannot represent“really”normal coronary arteries.The early stages of atherosclerosis and functionalabnormalities may persistent in patients with an-giographically normal coronary arteries.Intravas-cular ultrasound(IVUS)and intracoronaryDoppler flow wire technique(ICD)provide mor-phologic andfunctional information on coronary ar-teries.Studies have shown that IVUS demon-strates atherosclerostic plaques which remain an-giographically undeteted[1].…     

经胸二次谐波多普勒技术探测冠状动脉血流储备的研究

目的应用经胸二次谐波多普勒超声心动图(TTDE)检测冠状静脉窦血流储备(CSFR);与经食道多普勒超声心动图(TEE)探测左冠状动脉前降支血流速度计算血流储备(CFR)相对照,分析研究经胸探测冠状静脉窦血流储备(CSFR)可代替TEE的探测CFR可靠性。方法检测40例正常人,CSFR或CFR为潘生丁负荷试验后最大峰值血流速度与静息状态峰值血流速度的比值。利用TTDE探测CSFR,TEE探测CFR。结果TTDE探测CSFR的成功率为95%。TTDE所测的CSFR与TEE所测CFR值密切相关。结论TTDE为一种新的检测CFR的方法。     

经胸多普勒超声评价冠状动脉粥样硬化性心脏病患者冠状动脉血流储备

目的采用经胸多普勒超声技术评价冠状动脉粥样硬化性心脏病(冠心病)患者的冠状动脉血流储备(CFR)。方法2005年5月至2006年1月连续120例疑为冠心病的患者于冠状动脉造影(CAG)前1d进行心脏超声双嘧达莫(0.56mg/kg)负荷试验,测定左前降支(LAD)的CFR指标,包括收缩期最大CFR、收缩期平均CFR、收缩期流速时间积分储备、舒张期最大CFR、舒张期平均CFR和舒张期流速时间积分储备。结果82例患者(68.3%)获得LAD血流频谱,按照CAG结果分为显著狭窄(A组,狭窄≥70%,16例)和非显著狭窄(B组,狭窄<70%,66例)。A组各项CFR指标的平均值均显著低于B组(P值均<0.01)。无1例出现严重并发症。部分患者出现胸闷、胸痛、头晕或头痛等症状,经休息或吸氧后均自行缓解。结论冠状动脉显著狭窄患者的CFR显著降低。经胸多普勒超声检查适用于大多数冠心病患者,并且能够可靠地检出冠心病患者的CFR异常。     

经胸高频彩色多普勒超声评价高血压患者冠脉血流储备

目的 应用经胸高频彩色多普勒超声检测高血压患者的冠脉血流储备(CFR)功能.方法 25例高血压左室肥厚组(LVH),23例高血压无左室肥厚组(no-LVH)和25例正常对照组(所有病例冠状动脉造影未见异常).经静脉注射潘生丁,测量用药前、后心尖部心外膜冠状动脉的舒张期峰值血流速度,血流速度时间积分,计算其比值,作为冠脉血流储备指标.结果 高血压患者无论有无LVH,CFR峰值速度比、CFR速度时间积分比均较对照组明显减低,差异显著(P＜0.05,P＜0.05).结论 原发性高血压患者均存在冠脉血流储备功能降低.     

Effects of hypoxia on coronary flow reserve as determined by myocardial contrast echocardiography in swine

Background Time-intensity curves derived from microbubble destruction/refilling sequences and recorded using myocardial contrast echocardiography (MCE) can provide parameters that correlate with coronary blood flow. The response of these parameters to adenosine vasodilatation correlates with coronary flow reserve (CFR) measured by fluorescent microsphere techniques (FMT). Currently, no data exist regarding the effect of physiological variables, such as hypoxia, on the determination of CFR by MCE. The purpose of this study was to define the effects of decreases in blood partial pressure of oxygen (PO2) on CFR as measured by MCE. Methods Studies were performed in 9 closed chest swine. Low-energy, real-time MCE was performed with commercial instruments in short axis view at papillary muscle level while infusing BR1 at 30 ml/h. High-energy ultrasound bursts (referred to as FLASH frames) destroyed the bubbles every 15 cardiac cycles, and resultant time-intensity curves derived from these sequences were fitted to the exponential function y = A ［1-e（-bt）］ +c, from which the rate of signal rise (b) was obtained. CFR was calculated as the ratio of b values after adenosine infusion to baseline and was obtained during the control period and after decreasing blood PO2 by giving nitrogen via a respirator to create artificial hypoxic conditions. CFR was independently determined by FMT. Results Nitrogen led to significant decreases in mean PO2, from (120.6±18.9) mmHg to (51.8±15.9) mmHg (P&lt;0.01). Adenosine produced a similar increase in CFR (2.5 fold vs 3.1 fold) as assessed by MCE and FMT during the control period. The decrease in PO2 post nitrogen resulted in a slight increase in values at rest: 0.46±0.15 to 0.53±0.18 for b and (1.39±0.66) ml·min（-1）·g（-1） to (1.72±0.30) ml·min（-1）·g（-1） for myocardial blood flow (MBF) (both P&lt;0.05). In addition, values decreased in response to adenosine using both techniques: 1.05±0.35 to 0.82±0.27 for b and (4.30±3.16) ml·min（-1）·g（-1） to (3.93±1.27) ml·min（-1）·g（-1） for MBF (both P&lt;0.05). Thus, CFR was markedly reduced under hypoxic conditions, to 1.4 by MCE (P&lt;0.05 compared with the baseline), and to 2.5 by FMT (P&gt;0.05 compared with the baseline). Conclusions CFR values diminish under hypoxic conditions according to both MCE and FMT. The reductions in CFR involve both an increase in resting values and a decrease in post adenosine measurements, as determined by both techniques. The reduction in CFR under hypoxia is slightly greater using MCE than using FMT. Physiological variables, such as hypoxia, must be taken into consideration when assessing CFR by MCE.     

冠脉内多普勒血流速度描记评价介入治疗效果

目的 应用冠状动脉内多普勒血流速度描记技术,评价经皮冠状动脉球囊扩张术（ＰＴＣＡ）及支架植入术对冠脉血流储备的影响。方法 对２１支（１８例）有狭窄病变的冠状动脉进行ＰＴＣＡ术,其中１６支冠脉ＰＴＣＡ术后植入支架。在ＰＴ－ＣＡ前后和支架植入术后,采用Ｃａｒｄｉｏｍｅｔｒｉｃ ＦｌｏＭａｐⅡ血管腔内多普勒血流速度描记仪和多普勒导丝,测量狭窄近端和远端的平均峰值流速（ＡＰＶ）、舒张期与收缩期流速比（ＤＳ     

经食道超声心动图法测定代谢综合征患者冠状动脉血流储备的研究

目的应用经食道超声心动图（TEE）检测代谢综合征（MS）患者的左冠状动脉前降支血流,评价冠脉血流的变化及冠状动脉血流储备（CFR）。方法TEE结合潘生丁药物负荷试验分别测量47例代谢综合征患者和35例健康者的前降支中远端静息及最大充血状态时冠脉舒张期峰值血流速度及平均峰值血流速度,以最大充血状态与静息时的比值计算CFR。结果静息时两组的舒张期最大峰值血流速度（PDV）差别无统计学意义（P（0.05）;最大充血状态时,两组PDV均明显增快,对照组为（98.83±17.88）,MS组为（58.15±12.11）,但MS组增加的程度低于对照组（P（0.001）;MS组的CFR明显低于对照组（P（0.001）。结论MS患者的CFR是降低的,即MS患者由于冠脉微循环阻力增高导致冠脉微循环障碍。     

静脉心肌声学造影评估冠脉血流储备的实验研究

为评价经静脉心肌声学造影测定冠脉血流储备的能力，在开胸犬动物模型上观察了左前降支狭窄前后，经静脉注射含C_3F_8声振白蛋白葡萄糖溶液行心肌声学造影反映乙酰胆硷增加心肌血流灌注的能力。结果提示，左前降支狭窄前，心肌声学造影的时间－强度曲线显示，在注射乙酰胆硷后，峰强度，曲线最大上升／下降斜率及曲线下面积均明显增加，而达峰强度时间，峰强度减半时间及至峰强度减半时间则缩短（P＜0．01）。左前降支狭窄后，各参数变化同基础状态，但幅度均相应减小。其中峰强度和曲线下面积比率与冠脉血流测定值的相关性最好。结论：静脉注射含C_3F_8的声振液行心肌声学造影可定量冠脉储备。     

经胸超声测定冠状窦血流评价经PCI术后血流变化

目的应用经胸超声测定冠状静脉窦血流储备评价经皮冠状动脉血运重建术（PCI）后冠脉血流情况。方法选择62例临床诊断为急性心肌梗死的患者，经冠脉造影证实为左冠脉系统狭窄，均接受PTCA和支架置入，经胸超声等长握力试验测定手术前后冠状窦血流储备。结果术后冠状窦收缩期和舒张期峰值血流及积分均较术前增大，血流及积分储备较术前明显增加，差异具有显著性（P〈0．05）。结论经胸超声测定冠状窦血流可用于初步评价冠脉术后的血流灌注。     

Value of Acceleration Flow in the Left Anterior Descending Coronary Artery for the Detection of Coronary Artery Stenosis by Transthoracic Coronary Color Doppler Echocardiography

Transthoracic color Doppler echocardiographyhas been widely used to measure the coronary ar-tery flowvelocity reserve[1].It is useful to providei mportant informationfor diagnosis of coronary ar-tery disease and assessment of curative effect afterpercutaneous coronary artery intervention.Butthis evaluats onlythe effect of the stenosis on coro-nary artery flow velocity reserve during maxi malhyperemia reaction.Hemodynamics demonstratesthat localized flow acceleration is present at thestenotic s…     

Impact of uncontrolled blood pressure on diagnostic accuracy of coronary flow reserve for detecting significant coronary stenosis in hypertensive patients

Background Impaired coronary flow reserve (CFR) in patients with hypertension may be caused by epicardial coronary stenosis or microvascular dysfunction. Antihypertensive treatment has been shown to improve coronary microvascular dysfunction. The aim of this study was to evaluate the impact of uncontrolled blood pressure (BP) on diagnostic accuracy of CFR for detecting significant coronary stenosis.

Methods A total of 98 hypertensive patients scheduled for coronary angiography (CAG) due to chest pain were studied. Of them, 45 patients had uncontrolled BP (defined as the office BP ≥140/90 mmHg (1 mmHg=0.133 kPa) in general hypertensive patients, or ≥130/80 mmHg in hypertensive individuals with diabetes mellitus), and the remaining 53 patients had well-controlled BP. CFR was measured in the left anterior descending coronary artery (LAD) during adenosine triphosphate-induced hyperemia by non-invasive transthoracic Doppler echocardiography (TTDE) within 48 hours prior to CAG. Significant LAD stenosis was defined as >70% luminal narrowing. Diagnostic accuracy of CFR for detecting significant coronary stenosis was analyzed with a receiver operating characteristic analysis.

Results CFR was significantly lower in patients with uncontrolled BP than in those with well-controlled BP (2.1±0.6 vs. 2.6±0.9, P <0.01). Multivariate linear regression analysis of the study showed that the value of CFR was independently associated with the angiographically determined degree of LAD stenosis (β= –0.445, P <0.0001) and the presence of uncontrolled BP (β= –0.272, P=0.014). With a receiver operating characteristic analysis, CFR <2.2 was the optimal cut-off value for detecting LAD stenosis in all hypertensive patients (AUC 0.83, 95%CI 0.75–0.91) with a sensitivity of 75%, a specificity of 78%, and an accuracy of 77%. A significant reduction of diagnostic specificity was observed in patients with uncontrolled BP compared with those with well-controlled BP (67% vs. 93%, P=0.031).

Conclusions CFR measurement by TTDE is valuable in the diagnosis of significant coronary stenosis in hypertensive patients. However, the diagnostic specificity is reduced in patients with uncontrolled BP.

     

冠状窦及血流的经胸和经食管超声心动图检查

目的 :探讨经胸和经食管超声心动图对冠状窦检查的方法及其可行性。 方法 :经胸探查在标准心尖四腔切面基础上 ,探头稍向下倾。尽量压缩左心房 ,显示右心房。经食管超声探查采用变更的四腔切面。冠状窦在二尖瓣上 ,横置于左心房室沟的后缘 ,开口于三尖瓣隔瓣上右心房内。 结果 :经胸超声的检查成功率 6 0 % (18/ 30 ) ,冠状窦显示长度 (16 .5 3± 2 .5 7)mm ,宽度 (4 .5 1± 1.30 ) mm。经食管超声检查成功率 93% (2 8/ 30 ) ,显示长度 (2 4.11± 2 .46 ) mm ,显著长于经胸探查 (P<0 .0 1) ,宽度 (5 .0 6± 0 .97) mm ,冠状窦血流呈双期三峰 ,收缩期和舒张中期朝向基线下方 ,收缩期流速大于舒张中期 ,舒张晚期血流朝向基线上方 ,为右心房收缩时逆流入冠状窦。收缩期、舒张中晚期三峰的流速分别为 (39± 7.8)、(31± 6 .1)、(2 1±4.7) cm / s,速度时间积分分别为 (4 3± 11.6 )、(4 3± 13.0 )、(2 7± 8.2 ) cm / s,经胸探查因角度大于 40°不适合冠状窦血流探查 ,经食管超声则角度在 30°以内。 结论 :经食管超声探查冠状窦优于经胸探查。无创性冠状窦探查成功对判断冠状动脉血流储备和指导介入诊断与治疗 ,以及诊断某些先心病有一定价值。     

经胸超声冠状动脉血流显像评价左前降支狭窄的价值

目的应用经胸超声冠状动脉血流显像技术(TTDE)评价冠状动脉左前降支(LAD)全程显著狭窄(≥70%)。方法90例患者于冠状动脉造影(CAG)前用TTDE测量LAD各项血流指标,对比CAG分析结果。结果56段血管狭窄≥70%(狭窄组),121段血管无狭窄(对照组),两组比较,近、中段指标均存在差异,远段Vd/Vs、MVd/MVs,P<0.05。Vd/Vs、MVd/MVs≤1.7时,评价LAD显著狭窄的敏感度、特异度处于最佳点。结论应用TTDE检测LAD狭窄,无创、实用,具有临床价值。     

Current status of assessment of fractional flow reserve

Coronary angiography presently remains the main method tor the diagnosis and instruction of epicardial coronary disease. However, precise characterization of the significance for any given stenosis is limited by the inability to identify intermediate coronary lesions responsible for ischemia. In clinical practice, in addition to the assessment of the anatomical details of vessel narrowing, a more impediment to coronary precise assessment of the blood flow has become extremely important. At present, several physiological parameters have been introduced to improve discrimination in functional coronary lesion severity during cardiac catheterization. Of these parameters, myocardial fractional flow reserve （FFR） has been the most frequently used and is being increasingly applied to assess the functional significance of intermediate lesions. FFR can provide important information, both for decision making in diagnostic angiography and for monitoring and evaluating coronary interventions.     

病情控制状况对原发性高血压冠脉血流储备影响的研究

目的 :探讨病情控制状况对原发性高血压冠脉血流储备(CFR)的影响.方法 :选取经CT或冠状动脉造影检查确诊各支血管管腔直径狭窄均<50%的患者210例,其中非高血压患者56例作为对照组,高血压患者154例.按照患者体检测量的血压水平高低,将高血压患者分为正常组(30例,血压水平控制得较好,收缩压/舒张压<120/80 mmHg)、达标组(71例,血压水平控制达标,120 mmHg≤收缩压<140 mmHg,且舒张压<90 mmHg)与未达标组(53例,血压水平控制未达标,收缩压≥140 mmHg和(或)舒张压≥90mmHg).统计分析四组患者CFR、脉搏波速度(PWV)等临床指标的差异,多元线性回归分析原发性高血压CFR的影响因素.结果 :(1)未达标组年龄(64.6±6.2)高于对照组(57.9±12.1)、正常组(59.4±10.6)和达标组(60.6±9.5).(2)未达标组(9.4±1.62)舒张末期室间隔厚度(IVST)高于对照组(8.2±1.3)、正常组(8.5±1.1)和达标组(8.6±1.5);未达标组(7.6±1.9)与达标组(7.3±2.1)的二尖瓣舒张早期血流速度E峰/二尖瓣环侧壁舒张早期运动速度E'峰(E/E')明显高于正常组(6.4±1.8)、对照组(6.1±1.6).(3)未达标组bPDV(0.28±0.09)高于对照组(0.24±0.05)和正常组(0.24±0.04).未达标组CFR最低(2.56±0.47),其次是达标组(2.81±0.51),正常组(3.23±0.72)和对照组(3.29±0.66)最高.未达标组PWV最高(12.96±1.51),其次是达标组(10.83±1.22),正常组(9.15±1.43)和对照组(8.92±1.24)最小.(4)高龄、PWV升高、血压控制差是CFR下降的危险因素.结论 :血压控制在120/80 mmHg以下、PWV水平下降、低龄有利于改善无明显冠状动脉狭窄的原发性高血压患者的CFR水平.     

Quantitative Assessment of Coronary Flow Reserve by the Variables of Time—intensity Curve with Myocardial Contrast Echocardiography

The intrinsic limitations of traditional coro-nary angiography in diagnosis of coronary arterydisease are exposed increasingly.However,the as-sessment of coronary flow reserve ( CFR) is be-coming more and more important,which can rem-edy the disadvantages of traditional coronary an-giography.Myocardial contrast echocardiography( MCE) is a novel technique based on quantifyingmyocardial perfusion.However,the measurementand the resultof variables derived from time- inten-sity curve( TIC) with…     

组织多普勒成像和血流多普勒频谱研究冠心病患者左室舒张功能

目的：将组织多普勒成像（TDI）和彩色多普勒超声技术结合研究冠心病虱的左室舒张功能（LVDF）。方法：在心尖四腔心切面上用彩色多普勒超声检测80例心病患和79例相同年龄组正常人舒张早、晚期二尖瓣口血流频谱的最大速度（Vmax)时间速度积分（TVI）,同时用TDI技术检测左室外侧壁心肌收缩、舒张期运动频谱的Vmax和TVI,所有数据进行统计学分析。结果：两种技术所检测的正常人舒张早期峰的Vmax和TVI随着年龄的增长而降低,而舒张晚期峰的Vmax和TVI逐渐增高,冠心病患的数据变化与年龄关系不明显,主要与其心肌的病理变化程度有关,当二尖瓣口血流频谱出现“假性正常”、无法准确判断LVDF时,TDI技术的敏感性较高,它还可按检查的设计任意测量某一部位的心肌运动。结论：用血流多普勒频谱判断LVDF在一般情况下简单、方便。TDI技术可同时对左室收缩、舒张功能进行全面判断。     

代谢综合征患者冠脉血流储备变化及其影响因素的研究

目的探讨代谢综合征（MS）患者冠脉血流储备（CFR）的变化及其相关影响因素。方法选择37例患者20例正常人分别经食道超声心动图法（TEE）测定左冠状动脉前降支近端（LAD）血流储备,测定体重、身高、腰围、血压、血脂、血糖、尿酸。结果MS患者CFR为1.95±0.31,正常人CFR为3.75±0.72,MS的CFR较正常人明显降低（P〈0.001）;多元线性回归显示：体重、腰围、血压、血脂、血糖、尿酸是与CFR降低相关的危险因素（P〈0.05-0.001）;Logistic回归显示：腰围、收缩压是独立危险因素。结论MS患者存在CFR降低,且可能是由多种危险因素共同作用的结果。     

心肌声学造影在冠状动脉慢血流中的临床应用研究进展

 冠状动脉慢血流 (coronary slow flow,CSF)是指在冠状动脉造影时未发现有明显冠状动脉狭窄,而在末梢血管出现造影剂充盈延迟的现象。随着影像学技术的不断发展与提高,这种现象的检出率也随之上升,逐渐成为国内外学者的研究热点。心肌声学造影(myocardial contrast echocardiography,MCE)是评估心肌微循环血流灌注的一项新型诊断技术,本文对其在CSF中的临床应用研究进展作一综述。     

多普勒超声显像技术检测早产新生儿肠系膜上动脉和腹腔动脉血流

目的：通过对早产新生儿和足月新生儿的SMA和CA血流参数测定的对照研究，探讨国人早产儿生后早期胃肠道血液动力学的变化特点。方法：用彩色多普勒超声显像仪分别检测早产新生儿和足月新生儿生后第1天和第3天的肠系膜上动脉和腹腔动脉血流。结果：生后第1天早产儿肠系膜上动脉血流速度明显低于足月儿，血管阻力高于足月儿。生后第3天早产儿的血管阻力明显较第1天降低。结论：早产儿生后早期胃肠道血液动力学变化有其不同于足月儿的特点。