经静脉实时心肌声学造影评价犬急性心肌梗死的实验研究

目的 研究实时心肌声学造影检出犬急性心肌梗死的效果。方法 8只开胸犬结扎第一对角支起点以下冠脉左前降支主干,分别于结扎前、结扎后1h和3h静滴全氟显（5ml/min）进行实时心肌声学造影,左室乳头肌水平短轴切面观察造影效果和室壁运动,并与病理染色比较。结果 结扎后1h及3h,实时心肌声学造均能良好显示缺血区的造影剂充盈缺损,包括缺损大小、与形态,同时清楚显示缺血区室壁运动异常。与病理染色比较,充盈缺损区大于心梗区。闪烁显像很好反映出充盈缺损区周围心肌轿流再灌注减慢。结论 与病理染色比较,充盈缺损区大于心梗区。闪烁显像很好反映出充盈缺损区周围心肌血流再灌注减慢。结论 实时心肌声学造影可同时观察心肌灌注和室壁运动,闪烁显有定量评价心肌血流灌注的潜在价值,操作简便,具有良好的应用前景。     

术中冠脉血流显像技术评价急性心肌梗死犬心肌血流灌注的研究

目的探讨术中冠脉血流显像（CFI）技术观察急性心肌梗死犬心肌血流灌注的应用价值。方法18只健康开胸杂种犬于前降支分出第一对角支后约1 cm处结扎3小时建立急性心肌梗死模型。分别于结扎前、结扎3小时后应用i13L高频探头观察前降支远端及前壁心尖段心肌内血流灌注程度、血流方向,并测量心肌内冠脉血流速度,同时在以上观察时点经股静脉匀速推注造影剂（C3F8）行心肌声学造影（MCE）检查对照。结果18只犬均成功建立急性心肌梗死模型。结扎前降支3 h后,根据MCE显示前壁心尖段有无造影剂充填分为无侧支循环形成组（A组）和侧支循环形成不充分组（B组）,A组10只犬中,CFI显示60%（6/10）未见血流信号显示,40%（4/10）前壁心尖段内仅见星点状血流信号。B组7只犬中,CFI则均显示有少量血流信号,与基础状态相比,舒张期峰值血流速度（D-Vmax）、收缩期峰值血流速度（S- Vmax）及D-Vmax/S-Vmax比值均明显降低（P〈0.05）。另有1只犬MCE显示前壁心尖段造影剂充填良好,CFI亦显示丰富的血流信号,舒张期峰值血流速度（0.65 m/s）快于基础状态峰值血流速度（0.28 m/s）。结论术中冠脉血流显像技术能直观、无创、敏感地显示心肌血流灌注状态,与MCE比较,能更敏感的反映心肌血流灌注。     

经静脉心肌声学造影技术评价ATP敏感钾通道的开放对心肌缺血的保护作用

目的：证实经静脉心肌声学造影（MCE）,能够准确的测量缺血和梗死心肌的范围,并以此技术研究ATP敏感钾通道（KATP通道）开放对缺血心肌的保护作用。方法：21条犬随机分为三组：IR组：冠脉左前降支（LAD）闭塞90min,再灌注120min.NIC组：LAD闭塞前10min,静脉给尼可地尔100μg/kg,随后给予10μg/kg/min持续静滴至再灌注结束。CLIB＋NIC组：在IR组LAD闭塞前20min,静脉给予优降糖0．3mg/kg10min,随后步骤同NIC组。各组均在闭塞前状态、闭塞后1h、再灌注2h测定血流动力学指标;用图像分析仪测量TTC染色和危险心肌范围（AAR）和梗死心肌范围（IA）;经静脉注射全氟显示MCE,在左心室中部水平摄取短轴切面图像,冠脉闭塞1h心肌灌注缺损的范围为AAR,再灌注2h心肌灌注缺损的范围为IA。结果：冠脉闭塞1h,各组心输出量（CO）较基础状态低（P＜0．01）,再灌注2h,NIC组CO与闭塞前相比明显恢复,TTC测定AAR范围：各组之间无显著性差异（P＞0．05）。TTC测量IA范围：NIC组较IR组和GLIB＋NIC组明显缩小（P＜0．01）,MCE结果显示：与TTC染色的AAR有显著的相关性（r=0.975).IR组及GLIB＋NIC组的IA范围与TTC染色的IA范围也有显著的相关性（r=0.949)。结论：KATP通道开放剂尼可地尔能使心梗范围明显减小,经静脉MCE可准确测定缺血和梗死心肌范围。     

实时心肌超声造影评价急性心肌缺血的实验研究

目的 评价实时心肌超声造影(MCE)识别大鼠急性心肌梗死心梗范围的准确性,及定量分析缺血心肌血流灌注的特性.方法 雄性Wistar大鼠20只,结扎冠脉左前降支,制备急性心肌梗死(AMI)模型.分别采集基础状态及梗死状态下的RT-MCE 图像.分别在缺血区和灌注正常的心肌取感兴趣区,得出造影成像的强度-时间曲线,读出峰值视频强度PI、A、β、A·β值.结果 MCE显示梗死区灌注充盈缺损,灌注缺损区面积(30.67±6.42)%与病理染色证实的心梗面积相关性好(r=0.87).心梗区PI较正常灌注区低 (5.45±3.07) dB vs (23.03±5.27) dB (P<0.05).灌注缺损区的A、β、A·β值等均与正常心肌MCE灌注参数值间存在显著差异(P<0.05).结论 MCE能无创地准确估测梗死面积.梗死区MCE血流灌注指标显著降低.     

心肌声学造影和背向散射组织定征对犬顿抑心肌的研究

目的：研究犬顿抑心肌模型的血流灌注图像和背向散射组织定征信号的变化。方法：对9条健康杂种犬通过结扎左冠状动脉前降支（LAD）制作顿抑心肌模型,检测LAD结扎前、结扎后不同时间顿抑心肌图像的平均强度（AⅡ）及背向散射积分周期变化幅度（CVIB）。观察心肌血流灌注显像。结果：LAD供血区域心肌的AⅡ值、CVIB值及心肌血流灌注图像在LAD结扎前、结扎时,恢复再灌注后不同时间内发生了一系列变化。结论：心肌声学造影可清楚显示心肌的血流灌注状态,帮助判断冠脉支的走行和分布;背向散射心肌组织定征在评价不同血供状态、心动周期不同时相心肌内微小散射体的超声信号变化及其几何形态的变化方面有较大价值。     

对心肌预缺血保护作用的实验研究心肌声学造影超声心动图三维重建

目的 探讨心肌声学造影超声心动图三维重建（3D－MCE）对心肌预缺血（IP）的估测。方法 套扎健康犬左前降支或左旋支,建立开胸犬IP模型。IP组犬4只及再灌注（IR）组犬5支分别于基础状态、缺血4h、缺血后再灌注1h,应用经胸三维超声探头,经左房注射自制的声振5％白蛋白对其进行3D－MCE检查,并三维重建。动物处死后将左室短轴分为5－6个断面,用TTC病理染色确定危险心肌与梗死面积。结果 ①3D－MCE显示心肌总质量及造影剂充盈缺损心肌质量与病理实测值高度相关（r分别为0．93,0．92）。②3D－MCE及TTC染色结果均显示IP组心肌受损范围小于IR组。③IP组再灌注1h后灌注缺损心肌质量与再灌注即刻差异无显著性意义,P＞0．05。IR组再灌注1h后灌注缺损心肌质量较再灌注即刻增加,P＜0．05。结论 3D－MCE在定量诊断心肌梗死和心肌缺血范围时,可重复动态观察IP对活体心肌的保护作用。     

急性冠脉闭塞兔心肌微循环灌注的定量研究

目的通过心肌声学造影(MCE)定量评价急性冠脉闭塞后兔心肌的微循环灌注。方法将30只日本大耳兔随机分为:冠脉结扎模型组(MI组)和假手术组(Sham组),分别于开胸前、术后30min、2h及6h行常规心脏超声及MCE检查。结果成功制备兔冠脉结扎模型,兔左心收缩功能减低,MCE方法证明MI组术后造模节段心肌血流灌注量明显低于非梗死区、Sham组(P0.05)。结论通过MCE对心肌微循环灌注的定量评价,为临床诊断心肌缺血的部位和严重程度提供一定的参考价值。     

选择性心肌超声造影对冠状动脉介入治疗后即刻心肌灌注变化的初步研究

目的 采用选择性心肌超声造影（MCE）探讨冠状动脉介入（PCI）术后冠状动脉微循环改善情况。方法 对14例冠心病患者分别于PCI术前及冠状动脉开通后即刻经冠状动脉注射造影剂，在对比脉冲序列成像（CPS）条件下行MCE检查，对比观察心肌显影效果，并采用CUSQ软件进行脱机分析，计算心肌节段微血管灌注的平均灌注量（minivalue）。结果 冠状动脉内注入造影剂即刻能够获得清晰心肌显影，所有患者均获得较满意的左心室及心肌显影。14例患者中12例冠状动脉开通，2例冠状动脉慢性闭塞未能开通。13例于PCI术前MCE显示狭窄或闭塞冠状动脉的对应心肌节段显示节段性充盈减低或无造影剂充盈，1例慢性冠状动脉闭塞性病变患者冠状动脉造影显示侧支循环良好，MCE显示闭塞冠状动脉对应心肌节段充盈基本接近正常。冠状动脉成功开通的12例患者术后即刻MCE显示11例术前闭塞冠状动脉对应心肌节段充盈较术前改善，心肌节段微血管灌注的平均灌注量较术前增加（P〈0．05），1例改善不明显。结论 PCI能够有效改善病变心肌微循环，选择性MCE在CPS条件下能够准确、快速、有效地评价PCI后心肌再灌注情况。     

心肌声学造影评价硝酸甘油对犬心肌缺血再灌注损伤的延迟保护作用

目的　探讨心肌声学造影 (myocardial contrastechocardiography,MCE)技术评价硝酸甘油对犬心肌缺血再灌注损伤的延迟保护作用的价值。方法　 12只健康成年杂种犬随机分成缺血再灌注组和硝酸甘油组 ,缺血再灌注组不给予任何药物 ,保持基础状态 ,单纯给与左冠状动脉前降支结扎 180 min,再灌注 12 0 min,在持续缺血和再灌注阶段行心肌声学造影 ,硝酸甘油组 ,用微量静脉泵以 2μg/(kg· min)速度静滴硝酸甘油 1h,2 4 h后结扎左冠状动脉前降支 ,其余步骤同缺血再灌注组。于左室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 ,及缺血和再灌注阶段左室壁造影剂显影缺损区 (分别代表心肌危险区面积和坏死区面积 ) ,并与伊文思蓝及红四氮唑 (triphenyl tetrazolium chloride,TTC)心肌组织染色结果对照。结果　心肌造影时间 -强度曲线中 ,两组缺血低灌注区峰值强度 ,时间 -强度曲线下面积 ,比正常灌注区明显减低 ,峰值减半时间比正常灌注区延长 ,差异有显著性 ,缺血再灌注组、缺血低灌注区与正常灌注区心肌视频密度时间 -强度曲线参数比值较硝酸甘油组降低更明显 ,差异有显著性 ,MCE所测定的心肌坏死区面积与危险区面积之比与伊文思蓝及 TTC心肌组织染色结果成正相关。硝酸甘油可使心肌     

心肌造影检测冠状动脉微循环内皮损伤的初步应用研究

目的：探讨心肌超声造影（Myocardial contrast echocardiography, MCE）在检测冠心病早期冠脉微循环内皮损伤中的应用价值。资料与方法：选择冠状动脉造影（Coronary angiography, CAG）检查结果正常的患者20例为冠心病高危人群组（第2组）,另选年龄匹配的健康志愿者20例作对照组（第1组）行“声诺维”心肌造影。造影后进行4次闪烁成像,分析两组闪烁显像后心肌血流再灌注充盈曲线,获得再充盈峰值强度（PI）、达峰值强度时间（TP）以及心肌内微泡持续显影时间（T）并作定量分析。结果：第2组4次flash后的峰值强度均低于对照组（P<0.05）,达峰值强度时间（TP）以及心肌内微泡持续显影时间均明显大于对照组（P<0.05）。结论：MCE通过定量评价心肌微循环灌注可达到检测冠状动脉微循环内皮功能损伤的目的。     

心肌声学造影定量急性心肌梗塞后心肌血流量的实验研究

目的　评价心肌声学造影定量心肌梗塞心肌血流灌注的价值。方法　对６条犬急性心肌梗塞模型进行心肌声学造影, 采用自身对照的方法分析缺血区和非缺血区心肌显影时间－强度曲线各参数之比与心肌血流量的关系。结果　梗塞区时间－强度曲线各参数中, 曲线下面积（ＡＵＣ）和峰值强度（ＰＩ）与心肌相对血流量高度相关（ｒ＝ ０．９２和０．８４, Ｐ＜ ０．０１）, 与心肌绝对血流量相关性良好（ｒ＝ ０．７７和０．７１, Ｐ＜ ０．０１）。不同水平心肌血流量间的ＡＵＣ、ＰＩ均存在显著性差异（Ｐ均小于０．０１）, 且随着血流量的减少而呈下降趋势。三项时间指标与心肌绝对血流量无直接关系。结论　心肌造影时间－强度曲线参数中的曲线下面积和峰值强度可准确定量心肌梗塞后局部心肌血流量。     

谐波、超谐波心肌声学造影技术评价犬急性心肌梗死

目的探讨谐波(HA)和超谐波(UH)两种心肌声学造影技术评价心肌梗死的准确性。方法10条常规开胸犬动物模型,在基础状态、结扎冠状动脉左前降支1h后,分别应用HA和UH技术采集心肌声学造影图像,目测观察充盈缺损的范围,定量计算充盈缺损的面积,并与应用TTC染色测量的梗死心肌面积对比。结果TTC染色显示心肌梗死HA面积百分率为15.8%±2.4%,应用两种心肌声学造影模式计算的充盈缺损面积与解剖学梗死心肌面积高度相似,应用HA模式为15.5%±2.9%,应用UH模式为15.5%±3.0%。两种心肌声学造影模式检测急性心肌梗死HA的敏感性、特异性及诊断准确率分别为:在HA模式为88%、100%、94%;在UH模式为100%、75%、88%。结论两种心肌声学造影技术在诊断急性心肌梗死中均具有高度的准确性。     

急性冠脉闭塞犬心肌内血流改变的多普勒显像研究

目的应用冠脉血流多普勒显像技术观察急性前降支冠脉闭塞后后壁心肌内血流改变,并探讨这种变化的意义。方法15条杂种犬常规麻醉开胸后,应用冠脉血流程序观察前降支结扎后后壁内的血流信号改变,测量冠脉结扎前后后壁内血流速度,计算结扎后峰值血流速度和速度时间积分的变化值与结扎前相应指标之比;自主动脉根部注射Albunex进行心肌声学造影显像,观察前壁内造影效果,并进行造影评分,测量充填缺损区面积。结果根据前壁内显影效果,将实验犬分为A、B两组A组5条,前降支冠脉结扎后声学造影时前壁内完全未见造影剂充填,造影评分为0分;B组9条,声学造影时前壁内有不同程度的造影增强,评分为1或2分。A组结扎后后壁峰值血流速度变化分数[(V2－V1)/V1]和速度时间积分变化分数[(VTI2－VTI1)/VTI1]明显低于B组,差异有显著性意义[A、B两组(V2－V1)/V1分别为0.068±0.100和0.690±0.460,P＜0.01;(VTI2－VTI1)/VTI1分别为0.123±0.197和0.990±0.770,P＜0.01]。冠脉结扎后,两组前壁增厚率和左室射血分数均较结扎前明显降低,A、B两组各相对应参数间差异无显著性(P均＞0.05)。结论冠脉血流显像技术不但能发现冠脉结扎后靶血管供血区心肌内血流变化,而且可观察对侧心肌内血流的改变,在缺血区有侧支血流供应组(B组)对侧后壁内血流增加,通过对侧心肌内血流速度的变化,能间接判断侧支循环的开放情况。     

Noninvasive vessel-selective perfusion imaging with intravenous myocardial contrast echocardiography.

BACKGROUND: Intravenous myocardial contrast echocardiography (MCE) cannot identify each perfusion area of coronary vessels separately. However, by destroying microbubbles passing through a specific vessel using high-power ultrasound during intravenous MCE, vessel-selective perfusion imaging (VSPI) may be feasible. METHODS: In 10 open-chest dogs, intermittent short-axis images were obtained during contrast agent infusion using an ultrasound system. For VSPI, a probe coupled to another ultrasound machine was placed on the proximal left circumflex coronary artery (LCx). High-power ultrasound pulses were transmitted to destroy bubbles passing through the LCx. A negative contrast area on VSPI was considered to represent the perfusion area of the LCx (LCx-VSPI). A negative contrast area on conventional MCE during LCx occlusion and a region without staining by Evans blue dye were used as gold standards for defining the LCx perfusion area. LCx-VSPI was compared with a negative contrast area on conventional MCE during LCx occlusion and a region without staining by Evans blue dye. RESULTS: Despite lack of LCx occlusion, high-power destructive pulses produced a definite area of negative contrast on the LCx region. Decreased power of ultrasound pulses resulted in disappearance of the negative contrast area. An excellent relationship was demonstrated between both LCx-VSPI and a negative contrast area on conventional MCE during LCx occlusion (r = 0.93, P <.0001), and LCx-VSPI and a region without staining by Evans blue dye (r = 0.92, P =.0002). CONCLUSION: VSPI during intravenous MCE may be feasible for noninvasive assessment of perfusion areas associated with specific vessels.     

心肌声学造影评价梗死前心绞痛对心肌微循环损伤的保护作用

目的利用经静脉心肌声学造影(MCE)技术探讨梗死前心绞痛(PA)对急性心肌梗死心肌微血管损伤的影响。方法根据有无PA将首次急性心肌梗死(AMI)的37例患者分为两组,无PA组19例,有PA组18例。患者入院当天行心脏超声检查记录室壁运动和左室容积(EDV和ESV)。住院期间行MCE评价心肌危险区域中无再流范围。AMI后3个月再次行心脏超声检查评价左室重构。结果MCE显示无PA组心肌危险区域节段中无再流范围高于有PA组(P<0.05);EDV和ESV初诊时两组间无显著性差异。然而无PA组在3个月随访时超声结果显示左室容积较初诊时增加(P<0.0001),PA组左室容积较初诊时并无显著性改变。结论心肌梗死前心绞痛可以减少无再流,保护心肌微循环,有利于再血管化后左室功能的恢复,并防止左室重构的发生。     

自制心肌超声造影定量分析软件的设计与评价

目的评价自制心肌超声造影(MCE)图像定量分析软件对心肌灌注研究的可行性。方法根据阻断和再灌注冠状动脉时间不同,家兔被分为两组:阻断15min再灌注30min(Ⅰ组)和阻断120min再灌注60min(Ⅱ组)。分别于基础状态、冠状动脉阻断时和再灌注后行MCE,应用基于淘汰粒子群优化(EPSO)聚类算法的自制计算机图像定量分析软件对造影图像进行自动处理,获得多个心肌灌注定量参数。结果 (1)阻断时,Ⅰ组与Ⅱ组危险心肌的标化CI值均明显减低,与基础状态比较差异有统计学意义(t=5.104和t=4.327,P0.01)。再灌注后,Ⅰ组危险心肌标化CI值比阻断时增高(t=2.933,P0.01),与基础状态时相比仍减低(t=2.653,P0.01),Ⅱ组危险心肌标化CI值与阻断时相比差异无统计学意义(P0.05);(2)Ⅱ组危险心肌红色编码区和TTC中梗死心肌面积分别为(21.4±12.3)%和(18.0±9.5)%,且与TTC结果呈正相关(r=0.89,P0.01);(3)阻断时,危险心肌节段直方图呈偏态分布,再灌注后,Ⅰ组危险心肌基本恢复至正态分布,而Ⅱ组危险心肌仍呈偏态分布。结论基于淘汰粒子群优化聚类算法的心肌超声图像分析软件在定量评价心肌微灌注和识别灌注异常方面具有较好的可行性和较高的应用价值。     

心肌声学造影评价实验性顿抑心肌的微血管功能改变

目的 探讨心肌顿抑时心肌微血管功能改变以及静脉心肌学造影方法的价值。方法 制备左前降支冠脉（ＬＡＤ）不同阻断时间后再 灌注犬心肌凶模型,在不同观察时间点静脉注射含全氟丙烷声振白蛋白微泡造影剂,采用二次谐波成像和间歇发剂技术行心肌声学造影（ＭＣＥ）。由主动脉根部分别注射乙酰胆碱（ＡＣＨ）和硝酸甘油（ＮＧ）后重复ＭＣＥ并计算用药后,前二维超声上所示心肌灰阶峰值（ＰＶＩ）和峰值比值（ＰＶＩＲ）。结果（地     

3D perfusion mapping in post-infarct mice using myocardial contrast echocardiography

Myocardial contrast echocardiography (MCE) was used to construct three-dimensional maps of perfusion defects in closed-chest mice, with and without myocardial infarction (MI) induced by permanent coronary ligation. Contiguous, short-axis MCE cine images spanning the heart from apex to base were acquired at 1 mm elevations in each mouse. MCE images at each elevation were color-coded to indicate relative perfusion and were compared with postmortem histology. A strong correlation (R > 0.93) in the size of perfused areas was observed between in vivo measurements and the results of conventional ex vivo tissue staining. 3D multislice and 3D surface renderings of perfusion distribution were created and these perfusion maps also matched well with postmortem histology. These methods provide for the noninvasive determination of the total ischemic region placed at risk by coronary occlusion: this is a critical variable in assessing the potential of novel therapeutic agents to reduce MI size in murine models of ischemia/reperfusion injury.     

Fate of collateral circulation after successful coronary angioplasty of total occlusion assessed by coronary angiography and myocardial contrast echocardiography.

A well-developed collateral circulation is frequently observed in patients with total coronary occlusion. However, the fate of the collateral circulation after successful percutaneous transluminal coronary angioplasty (PTCA) has not been fully characterized. The purpose of this study was to compare the efficacy of coronary angiography and myocardial contrast echocardiography (MCE) in the evaluation of the collateral circulation after PTCA and to assess the temporal changes of the collateral circulation after successful PTCA of a totally occluded artery by using these 2 diagnostic methods. The study group was comprised of 20 consecutive patients (16 male, mean age 54 years) who underwent elective PTCA for total coronary occlusion. Coronary angiography was performed before, immediately after, and 24 hours after PTCA. MCE was also performed before, immediately after, and 24 hours after PTCA, by the intracoronary injection of sonicated radiographic contrast medium. According to the angiographic findings, the collateral circulation was graded on a scale of 0 to 3 as follows: 0 = no visible filling; 1 = collateral filling of side branches; 2 = partial collateral filling of the epicardial artery; 3 = complete filling of the epicardial artery. By MCE, myocardial perfusion by the collateral circulation was assessed by scoring the contrast pattern of collateral-dependent myocardial segments as follows: 0 = none; 0.5 = patchy or epicardial; 1 = homogeneous. The left anterior descending artery was occluded in 12 patients and the right coronary artery in 8 patients. Coronary angiographic collateral grades before PTCA were grade 2 in 5 patients and grade 3 in 15. PTCA with stenting was successfully performed in all patients without significant residual stenosis. Coronary angiography showed collateral circulation disappeared after PTCA in all patients. However, residual collateral perfusion was observed in 7 patients by MCE, performed immediately after PTCA (score 1 in 3 patients; score 0.5 in 4 patients). This residual collateral perfusion could be demonstrated even 24 hours after PTCA by MCE in 3 patients (all patients were 0.5 in myocardial perfusion score). In conclusion, successful PTCA with stenting of a totally occluded coronary artery leads to a disappearance of collateral vessels by coronary angiography in most of the patients. However, although angiographically not visible, coronary collateral circulation may persist even 24 hours after successful PTCA of a totally occluded artery demonstrated by MCE.