复流后高灌注心表冠脉血流与心肌微循环血流不匹配现象的实验研究

目的探讨短时间(2 min)冠脉缺血再灌注后反应性充血期心表冠脉血流与心肌微循环血流的动力学改变。方法12只成龄杂种犬开胸分离冠脉,环扎前降支第一间隔支以下部位2次,每次2 min,分别观察并记录缺血前后及再灌注后心率、收缩压、舒张压、平均压和再灌注后5、10、15、30、45、60、90和120 s时的心表冠脉血流和相应区域的心肌微循环血流。Doppler超声冠脉血流仪测心表冠脉血流,心肌声学造影测心肌微循环血流。结果反应性充血期心表冠脉血流和心肌微循环血流均有高灌注反应,但两者的动力学改变不同,表现出血流动态不一致即血流不匹配现象,并且心表冠脉血流的峰值血流明显高于心肌微循环血流。结论心肌短时间的缺血再灌注后会出现反应性充血期,这期间心表冠脉血流与心肌微循环血流发生不匹配现象,主要机制可能是毛细血管的征募和通血毛细血管的开放,对心肌的影响主要是增加心肌灌注,同时也使冠脉微循环的储备降低。     

计帧法在冠状动脉血流缓慢中的应用及相关危险因素

目的 探讨应用校正的心肌梗死溶栓治疗临床实验帧数(CTFC)方法测定冠状动脉血流缓慢患者血流速度的可行性,分析引起血流缓慢的相关危险因素.方法 选取2000年10月至2008年9月心血管内科住院疑诊冠心病经冠状动脉造影证实的冠状动脉血流缓慢者78例;同时选取年龄、性别匹配的经冠状动脉造影证实的冠状动脉血流正常者78例为对照组,两组入选者均采用CTFC法测定冠状动脉血流速度.结果 冠状动脉血流缓慢组CTFC帧数明显大于冠状动脉血流正常组,差异具有显著统计学意义.冠状动脉血流缓慢组低密度脂蛋白(LDL-Ch)明显升高,吸烟的比率增大.结论 应用CTFC方法测定冠状动脉血流速度缓慢者是可行的,吸烟和LDL-Ch升高可能是引起冠状动脉血流缓慢的危险因素,戒烟和积极调脂治疗有助于改善冠状动脉血流速度,改善临床症状.     

Non-invasive Assessment of Coronary Flow Velocity Reserve: A New Method Using Transthoracic Doppler Echocardiography

Coronary flow reserve (CFR) has been used toassess coronary microcirculation and epicardial coro-nary stenoses[1— 3 ] . CFR is defined as the ratio ofcoronary flow under maximal coronary vasodilatationto coronary flow under resting conditions[4 ] .Whenthe cross- sectional area of epicardial coronary arteriesis constant,coronary flow velocity (CFV) ratios areequal to volume flow ratios.The most common method used clinically formeasuring CFVR is intracoronary Doppler flow(ICD) analysis re…     

苦碟子对麻醉猫脑血流量及离体豚鼠心脏冠脉流量的影响

目的观察苦碟子对麻醉猫脑血流量及离体豚鼠冠脉流量的影响。方法分别采用Langendorff离体豚鼠心脏灌流模型及麻醉猫在体脑血流量实验的方法,研究苦碟子对其的影响。结果苦碟子能明显降低麻醉猫平均动脉压,增加脑血流量,降低脑血管阻力,增加离体豚鼠心脏冠脉流量。结论苦碟子具有调节心、脑血管阻力的作用,这可能是其抗心、脑缺血的作用机制之一。     

股动脉搭桥法测定冠状动脉血流量

目的：采用股动脉搭桥术测定冠脉血流量。方法：通过电磁流量计管型探头测定经股动脉搭桥灌注冠状动脉左前降支的血流量。结果：麻醉大冠状动脉血流量（ＣＢＦ）平均为５５．５ｍｌ／ｍｉｎ，静注扩血管药（钩藤碱Ｒｈｙ１０ｍｇ／ｋｇ）后，ＣＢＦ与该药的降压效应发生相应变化。结论：该法是一种简便、敏感、重复性好而可靠的ＣＢＦ测定法。     

银杏叶提取物对老年冠心病患者冠脉血流和内皮功能的影响

目的研究银杏叶提取物(GBE)对老年冠心病(CAD)患者冠脉血流和内皮功能的影响。方法50例老年CAD患者随机分为GBE注射液治疗组和对照组,两组均于用药前、后采用血管超声检测冠状动脉左前降支(LAD)血流和血流介导的肱动脉内皮依赖性血管舒张(FMD)的变化。结果GBE注射液显著增加LAD舒张期峰值流速(DPV)、收缩期峰值流速(SPV)和舒张期时间速度积分(DTVI)(P<0.01),同时FMD显著升高(P<0.01);而对照组冠脉血流和FMD无明显变化(P>0.05)。Pearson线性相关分析显示,LAD血流流速(DPV,SPV和DTVI)的增加与FMD的改善呈正相关(P<0.01)。结论GBE注射液可增加老年CAD患者LAD血流,其机理可能与FMD的改善有关。     

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…     

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.     

Left Coronary Artery Fistula Identified by Color Doppler Flow Imaging

ＬｅｆｔＣｏｒｏｎａｒｙＡｒｔｅｒｙＦｉｓｔｕｌａＩｄｅｎｔｉｆｉｅｄｂｙＣｏｌｏｒＤｏｐｐｌｅｒＦｌｏｗＩｍａｇｉｎｇＹＡＮＧＹａ（杨娅）；ＬＩＺｈｉ－ａｎ（李治安）；ＷＡＮＧＸｉｎ－ｆａｎｇ（王新房）；ＤＥＮＧＹｏｕ－ｂｉｎ（邓又兵）（Ｄｅｐａｒ...     

直视插管测定犬心脏冠状静脉窦血流量的方法

目的验证直视插管测定犬心脏冠状静脉窦血流量方法的可行性及有效性,并总结监测经验.方法12条杂种犬,随机分成组Ⅰ(主动脉阻断30min),组Ⅱ(主动脉阻断120min).全麻开胸后,抬起心尖,于心外膜冠状窦末端行平行"∪"型褥式缝合,经其中央逆心大静脉血流方向迅速插入自制的普通塑料管,插管深度0.8～1.5cm,量筒收集血标本并计时计量.结果与转流前比较,组Ⅰ45min后血流量明显增加,组Ⅱ75min后血流量明显增加.结论直视插管测定犬心脏冠状静脉窦血流量方法简便易掌握,不需要特殊导管和仪器,值得推广.     

主动脉瓣关闭不全与冠状动脉慢血流的临床研究

目的对冠状动脉慢血流病患者主动脉瓣反流和冠脉慢血流之间的关系进行探究。方法2009年2月～2011年8月,根据术前行超声心动图检查的结果,将河南省商丘市第一人民医院105例患者分为主动脉瓣反流组（57例）和无主动脉瓣反流组（48例）。两组患者的年龄、性别、高血压病等基本资料比较差异均无统计学意义（P〉0．05）,具有可比性。通过冠状动脉造影排除了严重狭窄方面因素的影响,对患者冠状动脉血流的情况加以观察,并且按照校正TIMI血流的分级方法进行评价和分析。对两组患者慢血流问题发生率以及疾病的程度加以对比。结果主动脉瓣反流组、无主动脉瓣反流组之间的造影校正TIMI帧数差异有高度统计学意义（P〈0．01）。随主动脉瓣反流的严重程度增加,患者的慢血流发生率显著增高。结论主动脉瓣反流患者的冠状动脉慢血流出现的概率会增高。     

择期PCI术前强化调脂治疗对冠脉前向血流的影响

目的:研究急性冠脉综合征(Acute Coronary Syndrome,ACS)患者择期经皮冠状动脉介入治疗(PCI)术前5天给予不同剂量辛伐他汀治疗后对术中冠脉前向血流的影响.方法:回顾性分析2005年6月至2010年6月确诊的ACS病人,PCI术前5天给予不同剂量辛伐他汀(标准组20 mg及强化组40 mg)各9...     

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.

     

冠状动脉造影指标对中度狭窄病变功能意义的判断价值

目的评估冠状动脉造影(coronary artery angiography, CAG)测定的指标对冠状动脉中度狭窄病变功能意义的判断价值.方法 46支CAG显示中度狭窄(直径狭窄率40%～60%)的冠状动脉,压力导丝测定心肌血流储备分数(myocardial fractional flow reserve, FFRmyo);定量CAG测量直径狭窄率和最小管腔直径.以FFRmyo<0.75为界限值,采用受试者工作特征曲线(receiver operating characteristic, ROC)选择CAG测量的每个指标的截断点.结果 46支血管病变的直径狭窄率(49.34±11.45)%,FFRmyo为(0.83±0.15),显著低于正常组(FFRmyo 为0.97±0.02).14处(30%)病变低于界限值(FFRmyo<0.75).CAG直径狭窄率与FFRmyo呈负相关(r=-0.59,P<0.01).以FFRmyo<0.75为界限值,根据ROC分析,直径狭窄率≥50%为截断点,灵敏度=63.64%,特异性=84.00%.最小管腔直径与FFRmyo呈正相关(r=0.62,P<0.01).以最小管腔直径≤1.5 mm为截断点,灵敏度=68.75%,特异性=89.66%.以直径狭窄率≥50%和最小腔直径≤1.5 mm联合计算,灵敏度=88.64%.结论 CAG直径狭窄率≥50%、最小管腔直径≤1.5 mm,能较准确地判断中度狭窄病变的FFRmyo.     

IABP对CABG术中乳内动脉旁路血流量的影响

目的研究IABP对CABG术中LIMA-LAD血流量的影响,以观察IABP的辅助效能。方法回顾60例IABP辅助下行CABG手术患者,术中使用TTFM直接测量并记录LIMA-LAD旁路血流波形曲线及PI值,分别记录反搏前后的旁路平均流量,进行自身对比研究。结果左乳内动脉旁路灌注呈现舒张期为主的单相灌注曲线。在未使用IABP时,LIMA-LAD旁路平均血流量为(30.15±10.30)mL/min,PI值为(2.89±0.81)。使用IABP后,旁路的平均血流量增加为(36.38±12.87)mL/min(P<0.01),PI值升高为(3.12±0.67)(P=0.184)。使用IABP可使LIMA-LAD旁路血流量增加约20.5%。结论IABP可显著增加LIMA-LAD旁路的血流灌注。     

经胸腔镜建立巴马小型猪冠状动脉狭窄模型

目的探讨一种高效、稳定的经胸腔镜构建不同程度冠状动脉狭窄动物模型的方法。方法20头巴马小型猪,在胸腔镜直视下手术丝线永久性环扎左前降支近端,从而造成前降支不同程度的狭窄。术后进行定量冠状动脉造影检查评价狭窄程度。结果20头小型猪中18头手术顺利完成,2头术中出现室颤,除颤成功后分别于术后8 h和48 h死亡。术后行定量冠状动脉造影显示7头小型猪狭窄程度不超过50%,6头狭窄程度在50%到70%,5头狭窄程度在70%以上,即时手术成功率100%,建模成功率90%。结论完全胸腔镜下应用丝线环扎法可成功地制作不同程度的冠脉狭窄动物模型。     

红外热成像系统对猪在体心脏冠脉灌注监测的作用

目的 研究红外热成像系统在实验猪心脏直视手术中对冠状动脉灌注情况监测的应用.方法 建立红外热成像术中监测系统,分别在实验猪心脏左冠状动脉前降支主干阻断前、阻断后以及解除阻断3个阶段,应用红外热成像监测系统观察和记录心肌灌注情况,分析数据,评价监测效果.结果 与阻断前相比,左冠前降支在阻断后其支配区域心肌表面温度明显降低,而这一变化在阻断解除后则迅速消失,其支配区域心肌表面温度恢复阻断前水平.结论 红外热成像系统对于在体实验猪冠状动脉灌注情况的监测具有良好的敏感性和准确性,其在非体外循环下冠状动脉旁路移植术中的监测价值值得研究.     

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。     

非冠心病胸痛患者心外膜脂肪与冠状动脉血流储备的相关性

目的:分析非冠心病胸痛患者心外膜脂肪组织(epicardial adipose tissue,EAT)与冠状动脉血流储备(coronary flow reserve,CFR)的关系,探讨EAT厚度对诊断冠状动脉微循环障碍的价值.方法:冠状动脉造影或冠状动脉CT证实各冠状动脉血管直径狭窄＜50％的非冠心病胸痛患者62例,经胸超声心动图测定EAT厚度及三磷酸腺苷负荷冠状动脉左前降支的CFR,分析EAT厚度与CFR的关系.结果:完成CFR测定者61例,平均CFR为2.98±0.67;其中出现冠状动脉微循环障碍,即CFR ＜3者34人(56％),平均CFR为2.52±0.32;CFR≥3者27人(44％),平均CFR为3.56 ±0.52.CFR ＜3组EAT厚度明显大于CFR≥3组[(3.4±0.8)mm vs.(2.3±0.6)mm,P＜0.001],EAT厚度与CFR呈显著负相关(r=-0.668,P＜0.001).Logistic回归分析显示,EAT厚度是冠状动脉微循环障碍的独立影响因素(OR =7.78,95％CI:2.44 ～24.79,P=0.001).ROC曲线分析显示,EAT厚度＞2.9 mm判断冠状动脉微循环障碍(CFR ＜3)的敏感性为82.4％,特异性为92.3％(曲线下面积0.860,P＜0.001).结论:冠状动脉微循环障碍患者心外膜脂肪厚度增加,心外膜脂肪厚度是冠状动脉微循环障碍的独立影响因素;心外膜脂肪厚度＞2.9 mm预测冠状动脉微循环障碍具有较好的敏感性和特异性.     

MMP-2在冠状动脉慢血流中的表达

目的测定冠状动脉慢血流(CSF)患者的血浆MMP-2的含量,并同正常患者(NSF)及急性冠脉综合征(ACS)患者相比较,以了解MMP-2在冠状动脉慢血流患者中的过度表达,是否可提示此类患者是否存在不稳定粥样硬化斑块。方法通过酶联免疫吸附测定法(ELISA)测定所选患者血清MMP-2浓度,其中冠状动脉慢血流32例,正常冠脉36例,不稳定型心绞痛24例,急性心肌梗死10例。结果 (1)在CSF与NCF两组患者之间血清MMP-2浓度差异呈显著性意义(P<0.01);(2)血清MMP-2浓度在CSF组与ACS组之间无显著性差异(P>0.05)。结论 (1)慢性炎症可能是CSF的发病机制;(2)MMP-2的过度表达预示CSF患者可能存在不稳定型动脉粥样硬化斑块。