小剂量腺苷负荷低能量心肌声学造影定量评价冠心病心肌灌注的临床研究

目的探索小剂量腺苷负荷低能量心肌声学造影（MCE）的量化指标是否能够准确区分冠心病患者正常、缺血以及再灌注良好的心肌。方法在标准半量（70μg^-1·kg^-1·min^-1）的腺苷负荷条件下用声学造影剂SonoVue和对比脉冲顺序（CPS）成像技术对14例冠心病患者进行心肌声学造影检查,在心尖四腔、两腔切面采集负荷前、负荷后心肌造影图像。用量化分析软件测量拟合图像满意节段的灌注曲线,并计算峰值强度（A）、曲线斜率（β）和灌注量（A·β）。根据患者冠状动脉造影（CAG）或64排CT冠状动脉重建成像（CTA）结果将获得的心肌节段分为无明显狭窄组（第1组）、成功再血管化组（第2组）和严重狭窄组（第3组）,比较各组负荷前后灌注指标A、β和A·β的差异,以及在腺苷作用下各组灌注指标的变化量以及变化率。结果49节段心肌中第1组20段（20／49）,第2组12段（12／49）,第3组17段（17／49）;各组负荷前后灌注指标比较,负荷条件下第1组和第2组灌注增强;第2组和第3组灌注指标的变化量和变化率均低于第1组,第2组A·β增加量高于第3组,第3组在静息状态下灌注无明显减低,但负荷后A、A·β变化量低于第1组和第2组（P〈0．05）;腺苷负荷后A·β〈1．74dB／s诊断冠状动脉狭窄和灌注缺损的敏感性和特异性均为71％;腺苷负荷后A·β增加率〈81％诊断病变血管灌注储备降低的敏感性和特异性分别为83％和79％,β增加率〈54％敏感性和特异性分别为86％和79％。结论小剂量腺苷负荷的量化低能量心肌声学造影能够增加冠心病的临床诊断准确率及经皮冠状动脉介入术（PCI）疗效评价的准确性。其中量化诊断的指标A-β稳定性最好,负荷条件下B、A·β增加率也有较好的诊断价值。     

Detection of acute myocardial ischemia during pharmacological stress in graded coronary artery stenosis: analysis of left ventricular asynchrony using Fourier phase imaging in pigs

Background: Stress echocardiography is increasingly used to identify coronary artery disease, but quantitative techniques are required to improve the accuracy of this method. Current algorithms used to analyze wall motion usually neglect motion asynchrony that is found in acute ischemia. Fourier phase imaging of echocardiographic images may offer the possibility to detect asynchrony, but its feasibility with dobutamine stress echocardiography (DSE) is undefined. The aim of this study was to investigate whether the extent of left ventricular asynergy can be used to quantify the severity of regional myocardial dysfunction and to detect functionally significant coronary artery stenoses during DSE. Methods: Regional wall motion abnormalities were induced by graded coronary stenoses (mild and severe) of the left anterior descending coronary artery (LAD) in seven open-chest anesthetized pigs. DSE (10–40 g/kg/min) was performed under control conditions and during sustained ischemia. Coronary flow was measured under resting conditions and during maximal hyperemic response due to intravenous infusion of adenosine. Functional significance of stenoses was defined as mild when coronary flow reserve (CFR) was reduced but > 1.5 and severe when CFR was 1.5. Echocardiographic cine loops were mathematically transformed using a first-harmonic Fourier algorithm displaying the sequence of wall motion as phase angles in parametric images and regional phase histograms. The phase difference (PD) of the first Fourier harmonic of posterior vs. anterior myocardial wall motion was calculated as an index of left ventricular asynchrony. Segmental fractional area shortening (FAS) and wall thickening (WT) as ratio of stress to rest served as a reference method of regional wall motion. Results: The increase in FAS (1.62 ± 0.6 vs. 0.42 ± 0.2, p = 0.0002) and WT (1.92 ± 0.5 to 0.3 ± 1.1; p = 0.004) in anterior regions during DSE was significantly higher in the control group compared to severe ischemia but not compared to mild ischemia. During graded ischemia, profiles of phase angles were consistently modified, showing a delayed onset in regional contraction. The mean PD during DSE in the control group was 10.4 ± 7°. PD rose in mild ischemic segments (CFR>1.5) to 28.9 ± 10° (p = 0.003) and to 89.6 ± 25° (p = 0.0002) in severely ischemic segments (CFR 1.5). There was a significant inverse correlation between the PDs and WT (r = –0.87, p < 0.0001). Normal WT ratios yielded low phase angles while segmental phase angles increased with decreased WT. The intraobserver variability of phase analysis was 2.7 ± 24° (mean ± 2SD). Conclusions: These results suggest that left ventricular asynchrony is an indicator of acute ischemia. Echocardiographic Fourier phase imaging is feasible to quantify wall motion displaying contraction sequence in a simple and objective format and is apromising approach for the clinical interpretation of stress echocardiograms.     

Quantification of myocardial perfusion and determination of coronary stenosis severity during hyperemia using real-time myocardial contrast echocardiography

Although regional myocardial perfusion can be currently quantified with myocardial contrast echocardiography (MCE) by using intermittent harmonic imaging (IHI), the method is tedious and time-consuming in the clinical setting. We hypothesized that regional myocardial perfusion can be quantified and the severity of coronary stenosis determined during hyperemia with MCE using real-time imaging (RTI) where microbubbles are not destroyed. Six open-chest dogs were studied during maximal hyperemia induced by adenosine in the absence or presence of coronary stenoses varying from mild to severe. Myocardial blood flow (MBF) was measured at each stage by using radiolabeled microspheres. MCE was performed using both IHI and RTI. Data for the latter were acquired in both end-systole and end-diastole. No differences were found between myocardial flow velocity (MFV) derived from IHI and RTI when end-systolic frames were used for the latter. MFV was consistently higher for RTI (P <.01) when end-diastolic frames were used. A linear relation was noted between MFV and radiolabeled microsphere-derived MBF ratios from the stenosed and the normal beds when end-systolic frames were used for RTI (r = 0.78, P <.001), whereas no relation was found when end-diastolic frames were used (r = 0.08, P =.78). The scatter for assessing MBF (A.beta) was minimal for IHI and RTI (9%-10%) with end-systolic frames, whereas that for RTI with end-diastolic frames was large (30%). Furthermore the correlation with radiolabeled microsphere-derived MBF was significantly (P <.01) weaker with RTI when end-diastolic frames were used (r = 0.53) than when end-systolic frames (r = 0.94) or IHI was used (r = 0.99). Data acquisition for IHI was 10 minutes, whereas it was 8 seconds for RTI. Thus, RTI can be used to quantify regional myocardial perfusion and stenosis severity during MCE. Only end-systolic frames, however, provide accurate data. RTI offers a rapid and easy means of assessing regional myocardial perfusion with MCE.     

Value of additional myocardial perfusion imaging during dobutamine stress magnetic resonance for the assessment of intermediate coronary artery disease

This study was performed to assess the role of additional myocardial perfusion imaging during high dose dobutamine/atropine stress magnetic resonance (DSMR-wall motion) for the evaluation of patients with intermediate (50?C70%) coronary artery stenosis. Routine DSMR-wall motion was combined with perfusion imaging (DSMR-perfusion) in 174 consecutive patients with chest pain syndromes who were scheduled for a clinically indicated coronary angiography. When defining CAD as the presence of a????50% stenosis, the addition of perfusion imaging improved sensitivity (90 vs. 79%, P?<?0.001) with a non-significant reduction in specificity (85 vs. 90%, P?=?0.13) and an improvement in overall diagnostic accuracy (88 vs. 84%, P?=?0.008). Adding perfusion imaging improved sensitivity in patients with intermediate stenosis (87 vs. 72%, P?=?0.03), but not in patients with severe (??70%) stenosis (93 vs. 84%, P?=?0.06). In patients with severe stenosis specificity of DSMR-perfusion versus DSMR-wall motion decreased (61 vs 70%, P?=?0.001) resulting in a lower overall accuracy (71 vs 74%, P?=?0.03). Using a cutoff of ??50% for the definition of CAD, sensitivity of DSMR-perfusion compared to DSMR-wall motion was significantly higher in patients with single vessel (88 vs. 77%, P?=?0.03) and multi vessel disease (93 vs. 79%, P?=?0.03), whereas no significant differences were found using a cutoff of ??70% stenosis for the definition of CAD. The addition of perfusion imaging during DSMR-wall motion improved the sensitivity in patients with intermediate coronary artery stenosis. Overall diagnostic accuracy increased only when defining CAD as ??50% stenosis. In patients with ??70% stenosis DSMR-wall motion alone had higher accuracy due to more false-positive cases with DSMR-perfusion.     

实时心肌超声造影评价冠状动脉不同狭窄程度患者心肌血流灌注

目的探讨静息状态下经静脉实时心肌超声造影(RT-MCE)评价冠脉不同狭窄程度患者心肌血流灌注的临床价值。方法根据冠状动脉(CA)造影结果,按CA狭窄程度将其所供应的心肌节段分为A组、B组及C组,其中C组再按有无冠状动脉侧支循环分成有侧支循环形成的C1组及无侧支循环形成的C2组。对25例冠心病患者及16例年龄相匹配的健康志愿者行RT-MCE,从MCE再灌注充盈曲线获得平台期峰值强度(A值)和曲线上升斜率(β值)分析心肌灌注。结果定性分析:病例组中有271个心肌节段MCE表现为灌注良好,81个心肌节段MCE表现为低灌注。定量分析:①A组及C1组的A值、β值及A×β值与对照组相比,差异均无统计学意义(P>0.05);②B组及C2组的β值、A×β值明显低于对照组,与对照组相比(β值分别为0.67±0.57vs0.97±0.65,0.65±0.80vs0.97±0.65;A×β值分别为4.51±3.89vs6.86±5.61,3.18±3.10vs6.86±5.61,P<0.05)。③当无侧支循环开放时,β及A×β值均随着CA狭窄程度加重呈不同程度递减,侧支循环开放,可能会高估CA狭窄时的心肌血流灌注。结论在静息状态下,RT-MCE可较好地发现冠状动脉狭窄程度>75%的心肌血流灌注异常。     

斑点追踪显像技术评价冠状动脉重度狭窄

冠状动脉粥样硬化性心脏病是常见的心血管疾病,严重危害身体健康。寻求无创的超声参数评价冠状动脉狭窄具有重要的临床意义。斑点追踪显像（STI）是评价心肌收缩功能的超声心动图新技术,不仅可用于评价心肌整体收缩能力,还可准确评价心肌各个节段的纵向应变、环向应变及径向应变。本文对斑点追踪显像技术在冠状动脉重度狭窄中的应用现状进行综述。     

Combined coronary and perfusion cardiovascular magnetic resonance for the assessment of coronary artery stenosis.

The purpose of this study was to evaluate the feasibility and accuracy of combined coronary and perfusion cardiovascular magnetic resonance (CMR) in the assessment of coronary artery stenosis. Thirty-five consecutive patients (27 men, eight women, age range 34-81 years), undergoing cardiac catheterization, were assessed with 3D coronary CMR and rest-stress perfusion CMR. Significant coronary stenosis was determined by vessel narrowing or signal loss with coronary CMR, and by abnormal contrast enhancement with perfusion CMR. Coronary artery diameter stenosis greater than 50% was considered significant with conventional cardiac catheterization. Seventeen patients had significant coronary artery disease, and in these there were 35 significant stenoses on cardiac catheterization. All left main stem arteries were normal on both cardiac catheterization and coronary CMR. For the diagnosis of coronary artery stenosis, coronary CMR had a sensitivity of 92% for the left anterior descending artery (LAD), 79% for the right coronary artery (RCA), but only 13% for the circumflex coronary artery (LCX). Perfusion CMR had corresponding sensitivities of 69%, 86%, and 63%, respectively. For all arteries the accuracies for coronary and perfusion CMR were 67% and 72%, respectively. Combining coronary and perfusion CMR improved the accuracy to 77%. These data demonstrate that in patients with suspected coronary artery disease, combined coronary and perfusion CMR is feasible, increases the accuracy of detection of significant coronary stenosis, and offers the possibility of combined anatomical and hemodynamic assessment of coronary artery stenosis.     

心肌SPECT灌注显像的心脏轴向移动校正

目的 对SPECT心肌灌注显像中心脏的轴向移动进行校正,以最大限度地降低运动伪影对诊断的影响.方法 通过电影、正弦图和回旋图显示,实现对心脏移动可视的定性评估;通过帧与帧之间的互相关函数方法,找出位移角度,对投影的校正给出建议值;经可视评估后,确定投影移动校正的初值;根据移动校正的初值重建图像,通过对重建图像的投影与采集投影的互信息分析,最后计算出投影移动校正.结果 心肌模型实验表明,本方法能够精确地复现模型的轴向运动,位置误差小于3 mm,经校正后重建图像改善明显.结论 本方法具有客观、精确、可视的优点,可精确确定和校正SPECT心肌灌注显像中心脏的轴向移动.     

实时心肌超声造影评价冠状动脉三支病变患者的心肌灌注

目的用实时心肌超声造影(real-timemyocardialcontrastechocardiography,RT-MCE)定量评价冠状动脉(冠脉)三支病变患者室壁运动和心肌血流灌注之间的关系。方法使用PhilipsSonos7500及S3探头,对32例经冠脉造影证实三支病变的患者经静脉给予SonoVue进行RT-MCE。将左室壁分为17节段,采用QLAB软件进行心肌灌注的定量分析。结果在异常冠脉供血区,有室壁运动异常节段的心肌血流量明显低于无室壁运动异常节段(1.86±1.09和10.82±5.54,P<0.01)。将血供异常但无室壁运动异常的心肌节段按供血冠脉的狭窄程度分为两组:供血冠脉狭窄程度≤70%组共50个节段,供血冠脉狭窄程度>70%组共135个节段。两组间的血管床横截面积(8.26±4.01和9.06±7.69,P>0.05)和心肌血流量值(11.20±10.5和9.07±11.01,P>0.05)差别无统计学意义,但后者的心肌局部血流速度值减低(1.45±0.38和1.05±0.21,P<0.05)。结论在冠脉三支血管病变中,无室壁运动异常区域的心肌血流速度与供血冠脉的狭窄程度有关。RT-MCE定量分析可用于评价冠脉三支病变患者的局部心肌灌注。     

心脏磁共振心肌灌注成像在冠心病患者冠状动脉病变及微循环梗阻中的临床应用价值

目的  探讨心脏磁共振（CMR）心肌灌注成像在冠心病冠状动脉病变及微循环梗阻（MVO）中的临床应用价值。方法  选取2020年1月~2022年12月我院收治的106例冠心病患者,均在经皮冠状动脉介入治疗前和治疗后行CMR心肌灌注成像。以冠状动脉造影诊断结果为金标准,对比经皮冠状动脉介入治疗前CMR心肌灌注成像中延迟强化透壁局部室壁异常运动及病变区与正常心肌区CMR心肌灌注成像参数。分析CMR心肌灌注成像对冠心病冠状动脉病变的诊断效能。经皮冠状动脉介入治疗后根据患者是否存在MVO将其分为MVO组（n=29）和无MVO组（n=77）,对比两组CMR心肌灌注成像参数,并采用ROC曲线分析CMR心肌灌注成像参数对MVO的诊断价值。结果  106例患者中的1802个心肌节段被纳入评价。CMR心肌灌注成像显示106例患者共有147个延迟强化的心肌节段（每个患者至少有1个心肌节段延迟强化）,其中68个透壁强化,79个非透壁强化。病变心肌首过灌注时间、首过灌注最大上升斜率（Slope_max）、心肌延迟强化信号值与正常心肌间对比有统计学差异（P < 0.05）。以冠状动脉造影结果为金标准,CMR心肌灌注成像对左前降支、右冠状动脉、左回旋支病变的诊断敏感度分别为94.12%、88.64%、88.89%,特异性分别为95.00%、96.55%、94.74%,准确度分别为94.66%、93.89%、93.13%。经皮冠状动脉介入治疗后有MVO者29例,无MVO者77例。MVO组中首过灌注时间、Slope_max、心肌延迟强化信号值与无MVO组的差异有统计学意义（P < 0.05）。ROC曲线显示,CMR心肌灌注成像参数中首过灌注时间、Slope_max、心肌延迟强化信号值对冠心病患者MVO诊断的曲线下面积分别为0.803、0.718、0.851,敏感度分别为82.76%、72.41%、86.21%,特异性分别为66.23%、68.83%、67.53%,准确度分别为70.75%、69.81%、72.64%。结论  CMR心肌灌注成像可显示冠心病心血管病变区域的变化,对诊断冠心病冠状动脉病变及MVO情况有较高的诊断价值。     

Distinction of non-ischemia inducing versus ischemia inducing coronary stenosis by fluorescent cardiac imaging

Intraoperative fluorescent cardiac imaging (FCI) can quantitatively assess myocardial perfusion abnormalities produced by graded flow-limiting coronary stenosis (FLS), but there are no data to distinguish FLS from non flow-limiting stenosis (NFLS) to determine their functional significance. The aim of the study was to evaluate whether non-ischemia inducing NFLS can be quantified and differentiated from FLS by FCI technology. Data are compared to gold standard fluorescent microspheres (FM). 11 domestic pigs of either sex underwent sternotomy. Left anterior descending coronary artery blood-flow was recorded by transit-time flow measurements. After baseline and Adenosine-induced hyperemia, two stenosis of low severity (50 and 90 % NFLS) were produced, followed by FLS (50 %) and total vessel occlusion. Time-dependent fluorescence intensity curves were recorded by FCI. Slope of fluorescence intensity (SFI) and background-subtracted peak fluorescence (BSFI) intensity were calculated and data compared to myocardial blood flow measurements using FM. All NFLS and FLS reduced myocardial perfusion as quantified by FCI showing decreased normalized BSFI and SFI (P < 0.001). Box-plot analysis showed significant difference between NFLS (50 and 90 %) and FLS (50 %) assessed by BSFI (P < 0.001) and SFI (P < 0.001). In each animal, a linear correlation between FM-derived myocardial blood flow and FCI-derived BSFI (r = 0.936, P < 0.001) or SFI (r = 0.942, P < 0.001) was observed during baseline, hyperemia, graded NFLS, and FLS. Both, BSFI (r = 0.789, P < 0.001) and SFI (r = 0.802, P < 0.001) significantly correlated with transit-time flow measurements. FCI quantitative technology is capable of distinguishing between non-ischemia inducing NFLS and ischemia inducing FLS showing a good correlation compared to fluorescent microspheres.     

核素心肌灌注显像与多层螺旋CT血管成像对心肌桥的对比分析

目的探讨99 Tcm-MIBI心肌灌注显像对心肌桥的临床价值。方法回顾性分析105例冠状动脉CTA诊断为心肌桥并接受运动及静息99 Tcm-MIBI心肌灌注显像的患者资料,分析心肌灌注显像结果,并与冠状动脉CTA结果进行比较。结果 105例心肌桥患者中,根据Nobel分级法,Ⅰ级狭窄21例,Ⅱ级狭窄24例,Ⅲ级狭窄60例;其中60例出现心肌缺血改变。缺血组与非缺血组心肌桥患者冠状动脉CTA显示狭窄程度的差异有统计学意义(χ2=61.731,P<0.001)。不同部位心肌桥血管支发生异常灌注的差异无统计学意义(χ2=3.588,P=0.166)。结论 99 Tcm-MIBI心肌灌注显像能够用于评价冠状动脉心肌桥。     

Diabetes and coronary artery disease: the role of stress myocardial perfusion imaging

Stress myocardial perfusion imaging (MPI) has the potential not only to improve clinical outcomes in diabetic patients, but also to decrease unnecessary use of health care resources. However, before routine screening can be recommended, cost-effectiveness analyses are required to identify patients in whom such testing is appropriate. Nevertheless, MPI is clearly emerging as a valuable tool for improving management of coronary artery disease in all patients with diabetes mellitus.     

定量组织速度成像与应变、应变率成像对冠脉不同狭窄程度心肌缺血的评估

目的:探讨定量组织速度成像(QVTI)、应变(S)及应变率(SR)成像对冠脉不同狭窄程度的患者心肌缺血程度的评估.方法:以冠脉造影为诊断标准,冠心病患者79例,正常对照组30例.所有入选者均测量基底段、中间段及心尖段收缩期峰值速度(Vs)、收缩期峰值应变(Ss)及其应变率(SRs),舒张早期峰值速度(Ve)及舒张晚期峰值速度(Va)、舒张早期峰值应变(Se)、舒张晚期峰值应变(Sa)及相应的应变率(SRe、SRa).结果:冠脉重度狭窄组患者的基底段、中间段的Vs、SRs、Ss、Ve及SRe,心尖段的SRs、Ve及SRe,基底段的Va及Sa均较对照组明显减低,差异有显著性(P<0.05).结论:QVTI与S、SR能定量评估冠脉病变狭窄程度>75%的患者心肌缺血状况,对早期诊断冠心病提供更多的信息.     

99mTc-MIBI心肌灌注显像与冠状动脉造影诊断冠心病的对比分析

目的：探讨99mTc-MIBI心肌灌注显像对冠心病的临床诊断价值。方法：128例住院患者，男76例，女52例。年龄30～85（56.5±12.5）岁。同时进行99mTc-MIBI心肌灌注显像与冠状动脉造影（CAG）检查，将结果进行相关性分析。对上述患者预后进行了抽样临床随访。结果：99mTc-MIBI心肌灌注显像与CAG均阳性65例，99mTc-MIBI心肌灌注显像阳性、CAG阴性32例，99mTc-MIBI心肌灌注显像阴性、CAG阳性22例，99mTc-MIBI心肌灌注显像与CAG均阴性9例。一种检查阳性和99mTc-MIBI心肌灌注显像与CAG均阴性预后良好。99mTc-MIBI心肌灌注显像与CAG均阳性，CAG证实主要冠状动脉狭窄≥75％预后较差。结论：99mTc-MIBI心肌灌注显像与CAG相辅相成，对冠心病患者的诊断、指导治疗决策和判断预后有重要临床意义。     

运用辅助装置进行多支血管不停跳冠脉搭桥术

目的:探讨应用辅助装置进行多支血管冠状动脉搭桥术的效果。方法:2003年6月-2006年11月本院多支血管病变冠心病患者35例,利用心尖吸引器辅助吸引上提心尖或左室侧壁,应用心脏吸引装置辅助下行冠状动脉搭桥术。结果:术中患者侧壁及下壁靶血管显露良好,术野改善,血压平稳,无严重心律失常发生。结论:对于多支血管病变(尤其是心脏较大)的冠心病患者,运用心脏吸引辅助装置进行冠状动脉搭桥术,可显著改善侧壁和下壁冠状动脉的显露,保证稳定的血流动力学和心脏跳动下靶血管的准确切开和良好吻合。     

应用药物负荷心脏MRI探讨冠心病心肌收缩功能与心肌灌注的关系

目的本研究主要探讨心脏MRI(CMRI)结合药物(小剂量ATP)负荷试验中,心肌收缩功能与心肌灌注之间、心肌收缩功能储备与心肌灌注储备之间的关系。方法我们采用1.5T磁共振扫描仪对68例冠心病患者进行了心脏电影MR成像,其中19例患者冠状动脉造影证实有阳性结果(血管狭窄>50%)。真正快速稳态梯度回波(FIESTA)序列用于观察静息状态下和小剂量ATP负荷状态下的心肌运动;平面回波成像(EPI)序列用于ATP负荷前后的MR心肌灌注成像。各序列均采用左室短轴位成像。电影MRI图像采用MASS软件包对左室各节段室壁运动进行半定量计分,同时对灌注曲线进行定量分析。最后对各节段心肌灌注参数和室壁运动评分进行统计分析。结果在静息状态和负荷状态下,心肌灌注参数均随着室壁运动评分的增加而降低。在小剂量ATP负荷状态下室壁运动较负荷前改善的心肌节段较无改善者的心肌灌注储备值低。结论心肌灌注和心肌收缩功能具有很好的相关性,对两者的综合判断有助于提高CMRI评估心肌活性的价值。     

冠状动脉病变与供血心肌损伤程度的对照分析

目的探讨心肌灌注MRI所示梗死心肌体积及分型与供血冠状动脉狭窄程度和位置的关系.方法 47例急性心肌梗死患者急诊接受冠状动脉造影及介入治疗,其后6～8周行心肌延迟灌注MR扫描,测定梗死心肌相对体积并分型.结果 22例患者单支冠状动脉完全闭塞,25例患者多支冠状动脉多处狭窄;MRI示前者延迟强化灶体积显著大于后者,以透壁型为主,后者以非透壁型为主.结论单支冠状动脉近端闭塞较多支冠状动脉多处狭窄更易造成大范围透壁心肌梗死.