经胸超声心动图测量冠状动脉血流储备的研究

目的探讨应用经胸超声心动图(TTE)检测冠状动脉前降支(LAD)远段血流评价冠状动脉血流储备(CFR)的方法学.方法17例受试者来自我院门诊健康查体的正常人,男性3例,女性14例,年龄30～47岁,平均(40.00±5.21)岁.LAD检测取变更的胸骨旁四腔切面,在彩色多普勒引导下,探查位于前室间沟心外膜脂肪内的冠脉前降支远段长轴切面,记录静脉注射双嘧达莫(0.56mg/kg,4分钟内)前后LAD血流频谱.CFR为静脉注射双嘧达莫后与静息状态时LAD血流速度比值.结果TTE检测LAD远段血流测量CFR的成功率为80.95%(17/21).基础状态时LAD内径为(1.81±0.25)mm,血流频谱由收缩期和舒张期两部分组成,药物负荷后血流速度明显增快,舒张期峰值流速比为3.27±0.47.结论经胸超声心动图测量冠脉前降支远段结构和血流为测量CFR提供了无创性的新方法,具有重要的临床意义.     

冠脉多普勒显像评估无复流时冠脉血流动力学变化的实验研究

目的 :应用冠脉多普勒显像观察犬急性心肌缺血再灌注时梗死相关动脉 (IRA)血流灌注模式的变化 ,了解该变化与心肌微血管损害之间的关系。方法 :1.健康杂种犬 19只 ,均结扎左前降支 (L AD) 60 min,而后分别再灌注 60 min (n=6)、 12 0 min (n=6)和 180 min (n=7) ;2 .心肌声学造影 (MCE)检查 :L AD结扎后 MCE检查确定的低灌注区为危险区 (RAMCE) ,再灌注后 MCE检查确定的低灌注区为无复流区 (NRAMCE)。若NRAMCE/ RAM CE比值大于或等于 2 5%时被认为发生了无复流现象 ;若 NRAMCE/ RAMCE比值小于 2 5%时认为心肌复流 ;3 .使用冠脉多普勒显像检测 IRA血流动力学各项指标。结果 :2只犬在实验中死亡 ,其余 17只犬均按方案完成了实验。 1.MCE结果 :复流组共有 7只犬 ,无复流组共有 10只犬 ;2 .再灌注 60 min时 ,PVs、 VTIs、 c FDs、PVd、 VTId、 c FDd、 DDR、 c DDD在复流组有所变化 ,但与基础状态比较 ,差异无显著意义 (P均 >0 .0 5) ;而无复流组的 PVs、 VTIs、 c FDs、 PVd、 VTId、 c FDd均明显减小 (P均 <0 .0 5) ,舒张期最显著的变化是减速度(DDR)明显增大 (P<0 .0 1) ,减速时间 (DDD)显著减小 (P<0 .0 1)。结论 :微血管床的损害可以影响心外膜冠脉血流动力学。这种变化可能主要是通过增加微血管阻力 ,     

经胸冠状动脉多普勒血流显像测定前降支支架植入术后远端血流的临床研究

目的　探讨经胸冠状动脉 (冠脉 )多普勒血流显像评估前降支支架植入术疗效的临床价值。方法　对 19例曾行前降支近段冠脉成形及支架植入术的冠心病患者进行冠脉多普勒血流显像检查 ,观察前降支远端冠脉血流信号 ,记录流速曲线 ,测定舒张期峰值流速 (PVd)、收缩期峰值流速 (PVs)及舒张期与收缩期峰值流速比值 (DSVR) ,并与正常对照组进行比较。结果　 19例患者中 11例前降支及支架内无明显再狭窄 ;8例有 >70 %的支架内再狭窄。无再狭窄组前降支远端血流均能清晰显示 ,PVd、PVs、DSVR与正常对照组差别无显著性意义 ;再狭窄组有 6例可测及前降支远端血流 ,PVd、DSVR明显低于正常对照组及无再狭窄组 ,2例未测及前降支远端血流。结论　经胸冠脉多普勒血流显像能直接观测前降支远端的冠脉血流 ,可为前降支冠脉支架植入术后的效果评估及是否发生再狭窄提供重要信息。     

经胸彩色多普勒冠状动脉血流显像技术对冠状动脉左前降支心肌桥的初步研究

目的 利用经胸冠状动脉血流显像技术研究左前降支（LAD）心肌桥患者的壁冠状动脉血流频谱特征以及硝酸甘油对血流频谱的影响;探讨应用经胸冠状动脉血流显像技术诊断心肌桥的可行性.方法 取32例冠状动脉造影检出的心肌桥患者作为研究对象,其中31例心肌桥位于LAD中段,1例位于远段, 静息及舌下喷服硝酸甘油后观察壁冠状动脉及其近、远端彩色多普勒及频谱多普勒特点,比较壁冠状动脉与其近、远端血流参数及诱发前后壁冠状动脉血流参数.结果 硝酸甘油诱发前后LAD中段彩色多普勒总显示率87.1%.静息状态12例患者壁冠状动脉段出现特征性的＂拇指征＂频谱,列为静息阳性组,诱发后出现＂拇指征＂频谱的10例患者列为诱发阳性组.诱发前彩色多普勒检出1例壁冠状动脉起始处舒张期花色血流,诱发后增加显示6例,其中1例出现收缩期反向蓝色血流,多普勒检查示诱发前后拇指征频谱与其近、远端比较舒张期峰值流速、舒张期平均流速、加速度差异有统计学意义;诱发前后＂拇指征＂频谱比较舒张期峰值流速、舒张期平均流速、加速度差异有统计学意义,壁冠状动脉受压时间差异无统计学意义.诱发后2例测及收缩期反向波频谱.结论 经胸冠状动脉血流显像技术是诊断心肌桥的一种新方法,应用硝酸甘油可提高心肌桥的检出率.     

经胸超声评价冠状动脉旁路移植术后乳内动脉桥血管通畅性

目的探讨经胸多普勒超声心动图(TDE)在冠状动脉旁路移植术(CABG)后评价桥血管通畅性的应用价值.方法经冠状动脉造影随访证实CABG术后左乳内动脉(LIMA)桥通畅者19例,应用TDE分别探查LIMA桥起始段、胸段、远段、吻合口及远段左前降支,测量各段收缩期峰值流速(SPV)、舒张期峰值流速(DPV)、收缩期速度时间积分(SVTI)、舒张期速度时间积分(DVTI),并计算舒张期与收缩期峰值流速比值(D/S)、舒张期速度时间积分分数(DF).结果LIMA桥起始段及胸段检查均成功18例(18/19),仅有3例患者D/S＜0.6,DF＜0.5;14例能清晰显示吻合口图像,LIMA桥远段、吻合口及远段左前降支血流参数测值比较差异无统计学意义(P＞0.05).与冠状动脉造影结果相比较,TDE多节段探查判断LIMA桥通畅的准确率为95%(18/19).结论采用TDE多节段探测LIMA桥是判断其通畅性的一种可行、可信并无创的方法.     

经胸冠脉血流显像检测左前降支支架植入前后局部血流动力学变化的临床研究

目的探讨经胸冠脉血流显像技术无创性检测左前降支支架植入术前后局部血流动力学变化以评价支架植入术疗效的临床价值。方法比较18例左前降支支架植入术患者术前、术后经胸冠脉血流显像所检测的血流动力学特征,并与冠脉造影正常组(29例)进行比较。结果18例患者冠脉造影证实左前降支存在60%～100%不同程度的狭窄,支架植入术后所有患者冠脉造影未见≥30%的残余狭窄。左前降支支架植入术前存在局部血流加速、左前降支和前间隔内逆向血流,支架植入术后局部血流加速现象消失,逆向血流处显示为前向血流。支架植入术前、后左前降支远段舒张期与收缩期峰值血流速度比值差异有显著性意义。结论经胸冠脉血流显像技术可以无创性评价左前降支支架植入术的疗效。     

经胸超声冠状动脉血流成像预测左前降支狭窄

目的评价经胸超声冠状动脉血流显像技术(TTDE)预测左前降支(LAD)狭窄的准确性.方法 65名临床怀疑为冠心病的患者,在静息状态下用TTDE探测LAD血流,计算舒张期血流速度与收缩期血流速度的比值(DSVR).患者在TTDE检查后24 h内接受冠状动脉造影检查(CAG).结果 53例患者的LAD血流得到探测和测量,其中14例有LAD显著狭窄(≥70%,狭窄组),39例无显著狭窄(对照组).狭窄组LAD的舒张期峰值血流速度和平均血流速度与对照组无显著差异(P＞0.05),但收缩期峰值血流速度和平均血流速度均高于对照组(26.4±11.8 cm/s vs 21.1±6.1 cm/s和18.1±7.8 cm/s vs 14.7±4.0 cm/s,P<0.05).狭窄组的峰值DSVR和平均DSVR较对照组小(分别为1.4±0.4比 2.0±0.5和1.4±0.4比1.9±0.4,P<0.0001).以平均DSVR≤1.6作为异常时,预测LAD狭窄的敏感性和特异性分别为85.7%和79.5%.结论用TTDE测定DSVR是一种简便无创的预测LAD狭窄的新方法.     

运用冠脉血流多普勒显像观察快速心房 起搏时犬冠脉的血流灌注模式

目的 观察静息状态及快速起搏时犬心外膜和心肌内冠脉的血流灌注模式。方法 运用冠脉血流多普勒显像技术，测量实验犬基础状态及快速心房起搏时左前降支冠脉及左室前壁心肌内冠脉峰值血流速度（V）和速度时间积分（VTI），并计算其增加率（△V%，△VTI%）,结果 快速起搏时，心外膜和心肌内冠脉仍保持各自的时相性血流灌注模式V和VTI比基础值明显增6高，且舒张期△Vd%高于△VTId%；心外膜冠脉血流舒张期VTI在全心动周期灌注中所占比例减小，而收缩期所占比例增大。结论 冠脉血流多普勒显像技术能实时而准确地反映静息状态和快速起搏时心外膜与心肌内冠脉的血流动力学特征。     

冠状动脉血流显像检测静息状态下左前降支狭窄的异常血流动力学表现

目的探讨经胸冠状动脉血流显像技术无创性检测左前降支狭窄时静息状态下的异常血流动力学表现。方法回顾性分析75例患者冠状动脉造影术前经胸冠状动脉血流显像检测的左前降支相关血流参数，比较冠状动脉造影证实的左前降支狭窄组（程度≥60％）与对照组（程度〈60％或正常）相关参数的差异。结果左前降支狭窄组存在局部血流加速、左前降支远端或前间隔分支内逆向血流。血流加速前的血流参数与对照组比较差异无显著性意义，血流加速处、左前降支远段相关血流参数与对照组比较差异有显著性意义，血流加速处与血流加速前相关血流参数的比较差异也有显著性意义。结论静息状态下左前降支狭窄程度≥60％时表现为狭窄处与狭窄前舒张期峰值流速之比增高（≥1．5），且左前降支远段舒张期与收缩期峰值流速比值下降．这些参数的异常有助于无创性评价左前降支狭窄。     

冠状动脉搭桥术前后内乳动脉桥及左前降支远段血流动力学改变的超声研究

目的应用常规超声结合冠脉血流显像技术观察分析冠状动脉搭桥术前后内乳动脉桥及远段左前降支血流动力学改变.方法行冠状动脉搭桥术患者46例,于手术前后超声检查左内乳动脉,其中38例患者检查左前降支远段.结果术后内乳动脉桥起始段显示率95.65%, 由术前收缩期优势型转变为术后舒张期优势型频谱.左前降支远段血流信号表现为流速及流速时间积分增加.结论常规超声结合冠脉血流显像技术可为冠状动脉搭桥术后随访提供一种无创的方法.     

肺静脉多普勒血流频谱识别肥厚型心肌病二尖瓣血流图假性正常化

为评价肺静脉多普勒血流频谱识别二尖瓣血流频谱假性正常化的价值,我们分析了22例肥厚型心肌病患者和22例正常人肺静脉血流频谱和二尖瓣血流频谱的差异.发现二尖瓣血流频谱正常的肥厚型心肌病患者,肺静脉血流频谱S波峰值流速、D波峰值流速、S/D比值、S波和D波流速积分的比值、A_R峰值流速和持续时间可表现异常(P<0.001).二尖瓣血流频谱异常的肥厚型心肌病患者,肺静脉血流频谱也表现异常(P<0.001).提示肺静脉血流图有助于识别二尖瓣血流图的假性正常化,深入研究有可能为评价左室舒张功能减退程度提供新途径.     

Noninvasive assessment of left and right internal mammary artery graft patency with high-frequency transthoracic echocardiography.

OBJECTIVES: The aim of this study was (1) to visualize internal mammary artery grafts (IMAG) on coronary artery by transthoracic echocardiography and (2) to assess the patency of the grafts. METHODS: Twenty-three patients (21 men, 56 +/- 6 years) with previous coronary artery bypass grafting were studied at baseline and after they underwent low-dose dipyridamole infusion. The parameters obtained were systolic (SPV) and diastolic (DPV) peak velocities and their ratio (DPV/SPV); the dipyridamole infusion to baseline ratio of DPV was an index of IMAG blood flow reserve (FR). Two groups of patients were selected at baseline: group A, (n = 12) with a DPV/SPV >1, and group B (n = 11), with a DPV/SPV <1. RESULTS: The IMAG was identified in all patients. Intraluminal flow signals obtained with pulsed wave Doppler showed a biphasic pattern (1 systolic and 1 diastolic wave). After dipyridamole infusion was administered, flow velocities increased in 11 of 12 patients in group A and in 5 of 11 patients in group B. In group A the DPV/SPV increased from 1.79 +/- 0.47 to 1.8 +/- 0.43 (P = not significant), and the FR was 1.8 +/- 0.4. In group B the DPV/SPV increased from 0. 46 +/- 0.05 to 0.5 +/- 0.09 (P = not significant), and the FR was 1. 3 +/- 0.41. Coronary angiography showed the graft patency in all patients in group A and in 5 patients in group B with increased flow velocity after dipyridamole infusion. In the identification of graft stenosis at baseline, DPV/SPV showed 100% sensibility and 58% specificity, and FR showed 92% sensibility and 84% specificity. CONCLUSION: Doppler echocardiographic evaluation of the IMAG is a simple noninvasive method to assess the functional impairment of the vessel.     

经胸壁多普勒超声心动图对冠状动脉血流的检测——与冠状动脉造影对照研究

目的探讨经胸壁多普勒超声心动图(TTDE)对冠状动脉远端血流检测的可行性.方法采用TTDE探查51例冠心病患者冠状动脉左前降支(LAD)远端及右冠状动脉后降支(PDA)血流,并与冠状动脉造影比较.结果 LAD的检出率为94%,PDA的检出率为75%,PDA未检出组的心率明显快于检出组.彩色多普勒冠脉显像为心底部朝向心尖部的舒张期持续的线状血流信号,脉冲多普勒显示以舒张期为主的双期血流频谱,有3例冠脉完全闭塞的患者检出舒张期负向血流.结论 TTDE可以较好地评价冠状动脉左前降支和右冠状动脉后降支血流,为临床提供一个无创的检查冠状动脉血流的新方法.     

Superior Vena Cava Doppler Flow Changes in Rabbits With Acute Thromboembolic Pulmonary Hypertension

Objective. The purpose of this study was to explore the superior vena cava (SVC) Doppler flow changes in rabbits with acute thromboembolic pulmonary hypertension (ATEPAH) and its value in evaluating pulmonary pressure. Methods. The systolic peak flow velocity (SPV), ventricular reverse peak flow velocity (VrPV), diastolic peak flow velocity (DPV), and atrial reverse peak flow velocity (ArPV) of the SVC were measured on end expiration with pulsed wave Doppler echocardiography in 30 rabbits with different degrees of ATEPAH. Linear regression and the Bland‐Altman method were used to analyze the correlation of Doppler flow velocities of the SVC to the catheter‐measured pulmonary arterial systolic pressure (PASP). Results. The SPV values of all groups were significantly lower after pulmonary embolism (PE) than before PE (P < .05). The VrPV values of the mild and the moderate groups but not the severe group were significantly higher after PE than before PE. The DPV values of the severe ATEPAH group were significantly lower after PE than before PE, but they were not lower in the other 2 groups. The SPV had a significantly negative relationship with the PASP (r = ?0.692; P < .0001). The VrPV/SPV ratios of all groups showed a significant positive correlation with the PASP (r = 0.698; P < .0001). The end‐diastolic diameter of the SVC gradually enlarged with the rapidly increased PASP and showed a significantly positive relationship in all groups (r = 0.594; P = .002). Conclusions. Analysis of the Doppler flow SPV and VrPV, the VrPV/SPV ratio, and the diameter of the SVC might provide an alternative method for catheterization in estimating pulmonary pressure.     

Assessment of coronary flow reserve with transthoracic Doppler echocardiography: comparison among adenosine, standard-dose dipyridamole, and high-dose dipyridamole.

Coronary flow reserve (CFR), defined as a ratio of hyperemic-to-basal coronary flow velocity, provides important information about the functional aspect of coronary circulation. However, it usually is determined by invasive methods during catheterization. Recent studies have shown that transthoracic Doppler echocardiography (TTDE) may be useful in the measurement of coronary flow velocity in the distal portion of the left anterior descending coronary artery (LAD). The vasodilators used for hyperemia are adenosine and dipyridamole. However, the coronary vasodilative response and systemic hemodynamic effects of the two agents have not been directly compared with TTDE. We assessed blood flow velocity and vascular resistance in the distal LAD by TTDE during an intravenous 2-minute adenosine infusion (140 microg/kg/min) and low- (0.56 mg/kg) and high-dose dipyridamole (0. 84 mg/kg) infusion in 25 patients with patent LAD. Coronary flow velocity was successfully recorded in 20 patients (80%) during baseline and the consecutive vasodilator-infusion period. Compared with low-dose dipyridamole, adenosine infusion induced a higher CFR (3.7 +/- 0.87 vs 2.73 +/- 0.65; P <.05) and a lower coronary resistance index (0.31 +/- 0.04 vs 0.35 +/- 0.08; P <.05). But by increasing the dipyridamole dose to 0.84 mg/kg, the values of the CFR and coronary resistance index became comparable to those of adenosine infusion (2.85 +/- 0.78 vs 3.03 +/- 0.7, P = not significant [NS]; 0.33 +/- 0.04 vs 0.32 +/- 0.09, P = NS; respectively). We conclude that adenosine seems to be a favorable vasodilator for the measurement of CFR with TTDE.     

高血压患者不同左室构型的肺静脉血流比较

目的 用脉冲多普勒超声评价不同左室构型高血压患者的肺静脉血流曲线。方法 对110例单纯高血压患者(男81例,女29例)进行二维和脉冲多普勒超声检查,根据左室重量及相对室壁厚度分成四种不同构型,比较四组间肺静脉血流曲线特点。结果 110例高血压患者中构型正常者占55.45％(61例),向心性重构者占21.82％(24例),向心性肥厚者占10％(11例),偏心性肥厚者占12.73％(14例)。肺静脉血流曲线示向心性肥厚组及偏心性肥厚组的VTIs、VTIs/(VTIs VTId)较正常组及向心性重构组低(P<0.05),ARD增大,ARD/AD延长(P<0.005)。结论 左室不同构型的高血压患者肺静脉血流曲线不同,提示向心性肥厚组及偏心性肥厚组左室舒张功能的损害较向心性重构组更明显。     

Ultrasonographic assessment of coronary flow reserve and abdominal fat in obesity

Recent technological advances in transthoracic Doppler echocardiography (TTDE) have provided noninvasive measurement of coronary flow velocity reserve (CFVR). We aimed to quantitate a correlation between endothelial dysfunction and fat distribution. In 36 patients with obesity, 16 with noninsulin-dependent diabetes mellitus (DM) and 12 healthy volunteers, coronary flow velocity was measured at the distal site of the left anterior descending branch. CFVR was defined as the ratio of hyperemic (IV infusion of 0.15 mg/kg/min adenosine) to basal peak diastolic flow velocity. Abdominal wall fat index (AWFI) was estimated by ultrasonography. Insulin resistance was quantified by the euglycemic hyperinsulinemic clump method. AWFI was significantly related to CFVR (r = -0.46, p = 0.011) and insulin resistance (r = -0.71, p < 0.0001). CFVR could be noninvasively evaluated using TTDE. Coronary endothelial dysfunction indicated as CFVR, body fat distribution and insulin resistance was quantitatively correlated in obesity.