心肌造影超声心动图实验犬模型的建立与应用价值

目的:建立用于心肌造影超声心动图的实验犬模型并探讨其应用价值.方法:将12条健康杂种犬静脉麻醉、人工呼吸机通气,正中切口开胸暴露心脏,行心外膜超声检查,阻断冠状动脉前降支4 h,造成急性心肌缺血模型,4 h后再灌注1 h,于冠状动脉阻断前、阻断及再灌注后不同时间经静脉注射自制造影剂进行心肌造影超声心动图研究.结果:12条犬经静脉注射造影剂后获得满意心肌造影图像,7条犬完成了全部的实验.结论:正中切口开胸犬心肌缺血模型可以成功地进行心肌造影超声心动图研究.     

心肌声学造影定量心肌血流判断存活心肌的初步应用

目的 了解临床上持续静脉滴注法心肌声学造影(MCE)定量心肌血流判断存活心肌的可行性与可靠性.方法 对19例前壁心肌梗塞患者行持续静脉滴注法MCE,设置不同触发间隔,采集图像后脱机分析及彩色编码.MCE检查后两天内完成正电子断层显像(PET).计算灌注正常区域和灌注缺损区域的A·β值,根据A·β值确定心肌存活与否,将判定结果PET进行对照.结果 16例病人(84%)获得满意图像,灌注正常区和灌注缺损区的A·β值分别为62.41±12.97、3.61±1.69,灌注缺损区标化后的A·β值都小于0.23,与动物试验所得结果相似,PET判定坏死的心肌节段,MCE示相应区域的A·β值显著减少,彩色编码示同一区域灌注缺损.结论 MCE能用于临床上从血流定量水平判断存活心肌.     

心肌声学造影评价心肌活力的初步临床应用

目的以心脏正电子断层显像(PET)为“金标准”,了解心肌声学造影(MCE)对存活心肌的诊断价值。方法选择11例前壁Q波心肌梗死成功血运重建后3~19月的病人,2 d内完成PET成像和MCE检查。结果坏死心肌的MCE灌注均为0分,存活心肌的MCE灌注多为0.5分,正常心肌的MCE灌注多为1分,不同等级的MCE计分对存活心肌的判断有显著性差异;MCE与PET判定结果具有良好的关联度(rp=0.78)。结论MCE能有效地评价心肌血流灌注,有可能成为临床评价存活心肌的新方法。     

心肌声学造影评价心肌活力的初步临床应用

目的 以心脏正电子断层显像（PET）为“金标准”,了解心肌声学造影（MCE）对存活心肌的诊断价值。方法 选择11例前壁Q波心肌梗死成功血运重建后3－19月的病人,2d内完成PET成像和MCE检查。结果 坏死心肌的MCE灌注均为0分,存活心肌的MCE灌注多为0．5分,正常心肌的MCE灌注多为1分,不同等级的MCE计分对存活心肌的判断有显著性差异;MCE与PET判定结果具有良好的关联度（rp=0.78)。结论 MCE能有效地评价心肌血流灌注,有可能成为临床评价存活心肌的新方法。     

无创性心肌声学造影评价急性心肌梗死再灌注后冠脉微循环的实验研究

目的:应用经静脉心肌声学造影(MCE)评价急性心肌梗死血管再通后的心肌微循环灌注情况.方法:30只中华小型猪,通过心导管介入法阻断前降支(LAD)120min,再灌注180min.在LAD闭塞及开通后分别行MCE,测定再灌注前后缺血心肌节段和正常心肌节段的视频强度值及心肌充盈缺损面积,计算无复流与危险区心肌面积比值(NRA/RA).进行心肌病理染色,计算NRA/RA.结果:LAD开通后TIMI血流均为3级.再灌注180min后,缺血心肌节段的视频强度较闭塞时有所增加(P<0.01),但仍明显低于正常心肌(P<0.01),可见充盈缺损区.MCE和病理染色测定的NRA/RA分别为39.68±23.06%和31.07±14.25%,结果无显著性差异(P>0.05),相关系数r=0.715.结论:MCE可作为一种准确、无创评价心肌微循环灌注的有效方法.     

MCE评价格列苯脲在硝酸甘油诱导心肌缺血再灌注损伤的保护作用

目的采用心肌声学造影(MCE)评价格列苯脲在硝酸甘油诱导心肌缺血再灌注损伤的延迟保护作用.方法24只犬左冠状动脉前降支(LAD)阻断180 min,再灌注120 min,分别于结扎前,结扎后即刻,180 min,再灌注后即刻、60 min、120 min时于左股静脉弹丸式注入MCE剂,分4组: A组(缺血再灌注组,6只),B组(硝酸甘油组,6只), C组(硝酸甘油+KATP拮抗剂组,6只),D组(KATP拮抗剂组,6只).MCE评价峰值声强度和曲线下面积.结果再灌注后即刻,四组心肌峰值声强度及曲线下面积明显减低;随着再灌注时间的延长,峰值声强度逐渐恢复.结论硝酸甘油对缺血再灌注损伤心肌微循环、微血管内皮功能具有延迟保护作用;硝酸甘油可能通过激活K离子通道诱导对缺血再灌注损伤心肌微循环灌注,微血管内皮功能的延迟保护.     

心肌声学造影、静息99m-锝心肌显像评价区域性心肌灌注的对比研究

为评价心肌声学造影（MCE）判定心肌灌注的可靠性，本文对27例冠心病和可疑冠心病人进行冠状动脉造影（CAG），经冠状动脉MCE和静息核素心肌灌注显象（SPECT）等三项检查。MCE采用计分法判定心肌灌注：1分，心肌回声均匀增强；0.5分，回声不均匀；0分，无心肌显影。SPECT采用圆周剖面曲线分析法。结果表明：与SCA对照，27例病人MCE和SPECT评价心肌缺血的敏感性和特异性高度一致，分别为90.0％，87.0％和66.7％，75.0％（P＞0.05）；两者与SCA的符合率均为85．0％。27例12支正常冠脉和32支病变冠脉的181个心肌节段中，MCE和SPECT评价心肌灌注有极好的相关性（r＝0．82P＜0．001）。     

氟碳微泡经静脉声学造影无创评价缺血和梗死心肌的实验研究

目的 :采用氟碳微泡声学造影剂及间歇二次谐波技术 ,评价心肌声学造影 (MCE)在缺血、梗死心肌诊断中的价值。方法 :建立开胸犬急性心肌梗塞动物模型 ,左前降支 (LAD)结扎 3h后 ,经静脉注射全氟显进行 MCE。于左室短轴乳头肌水平测定正常灌注区与缺血低灌注区心肌视频密度时间 -强度曲线参数及灌注缺损心肌范围。实验结束后心脏行组织学染色 ,比较两种方法所测的左室梗死心肌占左室心肌总面积百分比。结果 :心肌造影时间 -强度曲线中 ,正常灌注区与低灌注区的峰值强度 (PI)、强度减半时间 (T1/ 2 )、曲线下面积 (AUC)参数差异有显著性(13.5± 1.9vs2 2 .5± 2 .4 ;16 .6± 0 .9vs9.7± 0 .5 ;2 31.6± 14.9vs4 0 5 .6± 12 .3,P≤ 0 .0 1)。MCE所测定的左室梗死心肌占左室心肌总面积百分比与组织学染色所测定的实际百分比呈正相关 (r=0 .89,P=0 .0 1)。结论 :经静脉注射氟碳微泡声学造影剂 ,运用间歇二次谐波 MCE可定量心肌血流灌注 ,诊断心肌缺血 ,准确测定心肌梗死范围。     

实时心肌造影结合斑点追踪技术评价不同顿抑状态犬心肌微循环与收缩功能变化

目的:应用实时心肌造影技术(RT-MCE)和斑点追踪技术(STI),研究不同顿抑状态心肌的收缩功能和微循环的变化及相互关系,从影像可视化角度探讨顿抑心肌的生物学特征.方法:制作冠状动脉左前降支阻断后再灌注犬心肌顿抑模型,分为短顿抑组(阻断15 min)、长顿抑组(阻断45 min)和假手术组(不阻断),分别于阻断前、再灌注即刻、再灌注10、30、60、90、120 min进行MCE和STI检查.实验结束后,心肌标本行透射电镜检查.结果:再灌注即刻,长顿抑组和短顿抑组缺血心肌的径向应变和A·β均低于基础状态及假手术组,差异具有统计学意义(P＜0.01);随再灌注时间的延长,长顿抑组和短顿抑组缺血心肌A·β值较再灌注即刻时增高;至再灌注后30 min,径向应变峰值进一步降低,再灌注60、90、120 min,径向应变峰值有所恢复.再灌注120 min时缺血心肌A·β值和径向应变峰值仍低于基础状态和假手术组.缺血心肌血流量(Y)与径向应变(X)呈线性关系,可拟合直线方程,其回归方程与相关系数为Y=0.443+49.64X,r=0.80,R2=0.64,P=0.031(长顿抑组);Y=-2.184+65.88X,r=0.78,R2 =0.60,P=0.039(短顿抑组).结论:STI能够反映心肌微循环血流情况.STI结合MCE能反映顿抑心肌生物学特征的动态变化     

心肌声学造影与冠状动脉造影的对比分析

目的:对比研究超声心肌声学造影(MCE)与冠状动脉造影(CAG)对冠心病的诊断价值。方法:静脉注射声学造影剂Brocco产的声诺维(Sonovue)进行超声二次谐波心肌声学显影,按ASE推荐左心室分析法,将左室壁分为16段进行心肌灌注记分,分值与冠状动脉狭窄程度比较分析。结果:MCE检出心肌灌注异常与冠状动脉狭窄≥50%的符合率为76%,当心肌灌注MCE分值为0时,相应冠状动脉狭窄>75%的可能性为80.8%,而MCE分值为1时,相应冠状动脉狭窄≤75%的可能性为81.8%,冠状动脉狭窄各组之间MCE分值差异有显著性,P值均<0.01～0.001。结论:MCE能较准确地反映心肌血流灌注,从而判断冠状动脉病变的程度和部位,可作为冠状动脉造影筛选的一个有效的方法。     

利声显声学造影对犬冠脉阻塞前后心肌回声和灌注显像的影响

目的 :探讨犬左前降支 (L AD)阻塞前后利声显声学造影对心肌回声和血流灌注图像的影响。 方法 :健康杂种犬 11条 ,于 L AD阻塞前后注射利声显 ,用 HP Sonos 5 5 0 0型彩超仪、S4超宽频变频探头观察左室乳头肌水平短轴切面心肌回声和灌注显像。 结果 :L AD结扎前注射利声显 ,心肌灰阶值明显增高 ,由 6 2 .5 9± 10 .16增高到 79.2 8± 18.18(P<0 .0 1) ,灌注显像心肌亮度均值为 178.71± 10 .6 3。 L AD结扎后注射利声显 ,L AD供血段心肌灰阶值略增高 ,由 5 7.94± 9.6 4增至 6 4.2 6±16 .86 (P>0 .0 5 ) ,灌注显像不良 ,且回声不均匀。不同犬显像不良心肌的大小和位置不同。结论 :心肌声学造影可清楚显示犬冠脉阻塞前后心肌回声和血流灌注状态 ,并能间接判断冠脉支的走行和分布 ,在冠心病的研究中具有广阔的发展前景。     

Comparison of the veracity of real-time perfusion, harmonic angio, and ultraharmonic myocardial contrast imaging modes in evaluation of acute myocardial infarction area

Background Innovative advancements in ultrasound instrumentation present a number of imaging modalities for myocardial contrast echocardiography （MCE） in ischemic syndromes. How well they compare to each other in diagnostic accuracy in the detection of acute myocardial infarction is unclear. The purpose of this study was to assess the relative accuracy of 3 different imaging modes of MCE, low mechanical index （MI） real-time perfusion imaging （RTPI）, triggered harmonic angio mode （HA）, and ultraharmonic imaging mode （UH） in the detection of acute experimental myocardial infarction within the time frame suitable for potential reperfusion. Methods MCE was performed in 10 open-chest dogs using RTPI, triggered HA and triggered UH modes at baseline and one hour after occlusion of left anterior descending coronary artery. Presence or absence of peffusion defects, and the perfusion defect size when present, were analyzed and compared with the infarct size delineated by triphenyltetrazolium chloride （TTC） staining. Results The infarct area was （15.8-2.4）% by TTC staining; Peffusion defect area by MCE was similar to anatomic infarct area in all the three MCE approaches： （16.1-2.7）% by RTPI mode, （15.5-2.9）% by HA mode, and （15.5-3.0）% by UH mode. The sensitivity, specificity and overall diagnostic accuracy in the detection of myocardial infarction were 100%, 88%, and 94% for RTPI mode, 88%, 100%, and 94 % for HA mode, and 100%, 75%, and 88% for UH mode. Conclusion All modes of MCE, RTPI, triggered HA mode and triggered UH mode have excellent diagnostic accuracy in the immediate hour of acute coronary occlusion within the optimal time frame suitable for reperfusion therapy.     

Comparison of the veracity of real-time perfusion, harmonic angio, and ultraharmonic mocardial contrast imaging mode sine valuation of acute myocardial infarction area

Background Innovative advancements in ultrasound instrumentation present a number of imaging modalities for myocardial contrast echocardiography (MCE) in ischemic syndromes. How well they compare to each other in diagnostic accuracy in the detection of acute myocardial infarction is unclear. The purpose of this study was to assess the relative accuracy of 3 different imaging modes of MCE, low mechanical index (MI) real-time perfusion imaging (RTPI), triggered harmonic angio mode (HA), and ultraharmonic imaging mode (UH) in the detection of acute experimental myocardial infarction within the time frame suitable for potential reperfusion.
Methods MCE was performed in 10 open-chest dogs using RTPI, triggered HA and triggered UH modes at baseline and one hour after occlusion of left anterior descending coronary artery. Presence or absence of perfusion defects, and the perfusion defect size when present, were analyzed and compared with the infarct size delineated by triphenyltetrazolium chloride (TTC) staining.
Results The infarct area was (15.8±2.4)% by TTC staining; Perfusion defect area by MCE was similar to anatomic infarct area in all the three MCE approaches: (16.1±2.7)% by RTPI mode, (15.5±2.9)% by HA mode, and (15.5±3.0)% by UH mode. The sensitivity, specificity and overall diagnostic accuracy in the detection of myocardial infarction were 100%, 88%, and 94% for RTPI mode, 88%, 100%, and 94 % for HA mode, and 100%, 75%, and 88% for UH mode.
Conclusion All modes of MCE, RTPI, triggered HA mode and triggered UH mode have excellent diagnostic accuracy in the immediate hour of acute coronary occlusion within the optimal time frame suitable for reperfusion therapy.

     

缺血预适应对猪急性心肌梗死再灌注后无再流的影响

目的评价缺血预适应(IPC)防治猪急性心肌梗死(AMI)再灌注后无再流的作用.方法中华小型猪24只随机分成对照组、IPC组和假手术组,每组8只.冠状动脉结扎3 h,松解1 h制备AMI再灌注模型.AMI前、AMI后3 h和再灌注1 h后均行血流动力学测定,包括左室收缩压(LVSP)、左室舒张末压(LVEDP)、心排量(CO)和左心室内压最大收缩和舒张变化速率(±dp/dtmax).各组使用电磁流量计于AMI前5 min,对照组和IPC组于再灌注后即刻和1 h时记录冠脉血流量,应用心肌声学造影(MCE)检查及病理学分析测定无再流范围(ANR).结果与AMI前相比,对照和IPC两组AMI后3 h和再灌注后1 h LVSP、CO和±dp/dtmax均显著下降(P＜0.05,P＜0.01),LVEDP显著升高(P＜0.01);对照组再灌注后1 h仅LVSP比AMI后3 h显著恢复(P＜0.05),±dp/dtmax继续显著下降(P＜0.05);IPC组再灌注后1 h LVSP、LVEDP、±dp/dtmax和CO均比AMI 3 h显著恢复(P＜0.05,P＜0.01).IPC组MCE和病理染色所测的冠脉结扎区心肌范围高度一致(P＞0.05),再灌注后ANR分别为(16.4±2.24)%和(17.5±2.87)%,心肌坏死范围(NA)占LA的(78.4±3.62)%;IPC组结扎区心肌范围与对照组相比,差异无显著性(均P＞0.05),但两方法所测ANR和NA均显著小于对照组(P＜0.05,P＜0.01).对照和IPC两组再灌注即刻和再灌注后1 h冠脉血流量明显低于AMI前(均P＜0.01),IPC组再灌注即刻和再灌注后1 h冠脉血流量均比对照组显著增加(P＜0.05).结论IPC能有效防治心肌梗死再灌注后无再流,改善心功能,缩小梗死面积.     

QUANTITATIVE ASSESSMENT OF MYOCARDIAL PERFUSION DEFECTS WITH REAL-TIME THREE-DIMENSIONAL MYOCARDIAL CONTRAST ECHOCARDIOGRAPHY

QUANTITATIVE assessment of perfusion defectswith myocardial contrast echocardiography(MCE)could be a promising tool in the evalu-ation of patients with coronary artery disease·With the im-provement of microbubble contrast media and correspond-ing develop…     

心肌声学造影的发展及研究现状

心肌声学造影(MCE)是指注射声学造影剂后应用三维或多普勒超声技术观察心肌灌注的新型诊断技术。近年来,MCE已从实验室研究走向临床应用,成为临床上实时、安全、准确评价心肌灌注的诊断技术,广泛用于心肌梗死的诊断,评价冠状动脉介入及旁路移植手术的疗效,评价心肌存活性,鉴别冬眠及顿抑心肌,评价冠状动脉血流速度储备功能等,且在心脏疾病治疗中具有极大的潜在价值。     

Assessment of coronary artery disease with second harmonic myocardial perfusion contrast echocardiography

Objectives To assess the relationship between myocardial regional perfusion using second harmonic myocardial contrast echocardiography (MCE) by venous injection of Levovist and coronary artery stenosis detected by coronary angiography to determine whether MCE can be used to detect coronary artery disease (CAD) and its sensitivity and specificity for detecting CAD.Methods Thirty-six patients who underwent coronary artery angiography and MCE formed the study groups.Ten myocardial segments (5 each in the apical two- and four-chamber views) from the images were scored for detecting myocardial perfusion as follows: 1, normal perfusion; 2, decreased perfusion; and 3, perfusion defect.The arteries were classified as normal or diseased.The diseased arteries were classified into three groups according to the perfusion scores.Results There were significant differences in coronary diameter stenosis among the different perfusion score groups (P&lt;0.001).There were 10 total occluded arteries, and the myocardial perfusion scores were different because of different collateral circulation.In the normal perfusion group (Group A), the coronary diameter stenosis was 65%±12%, and the myocardial perfusion score index was 1±0.00.In the decreased perfusion group (Group B), the average coronary diameter stenosis was 82%±8%, and the myocardial perfusion score was 1.93±0.16.The diameter stenosis was less than 85% in 63 % of the coronary arteries (including diameter stenosis ≤75% in 12% of the vessels).The diameter stenosis was 85%-90% in 22% of the coronary arteries and &gt;90% in 15% of the arteries.In the perfusion defect group (Group C), the average diameter stenosis was 90%±6%, and the myocardial perfusion score index was 2.89±0.24.The diameter stenosis was　≥85% in 94% of the coronary arteries, and the diameter stenosis was &lt;85% and &gt;75% only in 6% of the coronary arteries.The overall sensitivity and specificity of MCE in identifying angiographic coronary diameter stenosis was 67% and 100%, respectively.The false negative rate was 32.6% for the 108 coronary arteries.Further subdivided analysis showed the sensitivities in Groups A, B and C were 0, 100%, and 100%, respectively.The sensitivity increased with increased lumen diameter stenosis of coronary arteries.Conclusions There is a close relationship between coronary artery stenosis and MCE perfusion scores.MCE with venous injection of new generation contrast can define the presence of CAD and lesion graded classifications.Some disagreements between perfusion score and coronary diameter of stenosis may indicate other factors such as different collateral circulation, which should be further investigated.As artery stenosis increases, the sensitivity of MCE is increased.     

急性缺血再灌注后心肌微血管床损伤的心脏MR影像研究

目的应用心肌首过灌注MR影像分析单支冠状动脉闭塞和多支冠状动脉狭窄无闭塞所造成的心肌微血管床闭塞差异.方法33例患者临床诊断为急性心肌梗死,其中15例为单支冠状动脉完全闭塞,18例为多支冠状动脉狭窄.发病后6～12周进行心脏MR影像检查.结果11例单支冠状动脉完全闭塞和4例多支冠状动脉狭窄患者的左心室内膜下心肌内存在首过灌注缺损区,前者显著多于后者(P＜0.01).心肌首过灌注缺损区域的信号强度峰值和信号增加的最大斜率显著小于灌注正常心肌(P＜0.05).结论心肌灌注首过时相影像能够显示急性缺血再灌注损伤所导致的心内膜下微血管床闭塞.单支冠状动脉闭塞的患者较多支冠状动脉狭窄的患者更容易发生心内膜下的微血管床闭塞.     

心肌声学造影在经皮冠脉成形术中的应用

为探讨心肌声学造影（MCE）在经皮冠状动脉成形术（PTCA）中的应用价值，对14例冠心病人于PTCA术前后经冠状动脉完成MCE，观察心肌影象增强计分，心肌灰阶峰值强度（PI）和心肌节段半径缩短率（D％）等指标的变化。结果：心绞痛病人20个心肌节段术前有7个节段MCE计为1分者，术后仍为1分，术前13个节段为0．5分者术后有8个节段升级为三分，PI及△D％均有相应改善（P＜0.01）；7例心肌梗塞病人共分析了16个心肌节段，术前有12个节段MCE计分为0者，术后有9个节段的MCE计分升级，PI及△D％也得到改善，提示有存活心肌。联合观察3项指标可从心肌灌注水平评价PTCA效果。