The authors thank the echocardiographic study subject for volunteering in the video as well as Witten/Herdecke University and HELIOS Research Center (HRC-ID 000416 assigned to Kai O. Hensel) for funding.

该协议内容的威滕/赫德克大学伦理委员会已经批准了道德。 1.技术要求<ol><li>利用配备了充足的部门数组组织谐波成像传感器的超声心动图检查设备都配有斑点追踪技术。 </li><li>在图像采集，记录，并直接以超声心动图的动态影像机电活动同步连接标准的3导心电图的超声心动图设备。这是强制性的在随后的后处理分析时间的目的。连接研究受EKG和解冻超声波图像来开始检测EKG信号。 </li><li>如下面详细说明的记录数字环路（步骤2.1-2.5）和数据存储作为外部磁盘上移动以DICOM格式的图像。接着，将文件传送到一个离线工作站。 </li><li>执行后处理分析使用适当的软件所概述下面详细（步骤3.1-3.13）。 </li></ol> 2.超声心动图数字化循环的录音<ol><li>检查（左侧与头部上方伸展左臂患者仰卧）在左侧卧位病人。 注:这部分协议要求患者/研究对象是存在。 </li><li>另外，结合超声心动图的方式STE如自行车测力计的时候，确保病人是一个45度的垂直位置。在这种情况下，利用标准的自行车测力装置和如先前所述11进行标准的超声心动图检测。在超声图像的记录时，倾斜测力计来实现，以尽量减少由干扰肺组织伪像的左外侧本体的位置。 </li><li>请特别小心，以优化图像质量，以保证心肌变形的准确评估。这样做，调整6之间的帧速率每秒0和80帧使用"调整帧速率"选项。此外，要注意包括将整个心动周期的整体分析的心肌结构的各个方面。 </li><li>获取标准心尖长轴和胸骨旁短轴飞机由欧洲协会心血管影像与超声心动图12的美国社会中描述的横截面二维灰度B型图像。记录几个连续的心动周期（实际上只有一个是必要的，至少有三个心脏周期的记录，以便能够选择一个与随后的后处理过程中的最佳图象质量决定）在以下每个平面: <ol><li>对于纵向ε和SR的评估，捕捉如前面所述12个标准心尖4，3，2分庭的意见。要做到这一点，在心脏附近的心尖搏动顶点（通常是B位置传感器etween的3 次和第 5 次肋间和中期锁骨和腋前线之间）。目的是在该右肩和有棱有角传感器，直到可见所有感兴趣的解剖结构。 </li><li>记录的图像中的二尖瓣，乳头肌和顶点以检测在细节12别处所述圆周ε和SR以及径向ε和SR的电平胸骨旁短轴图。要做到这一点，把探头左侧胸骨旁边界在第2 次或第 3肋间有棱有角，并直到你获得LV的剖视图垂直。 </li></ol></li><li>当心脏压力测试，如自行车测力或任何其他功能测试方式需要连续测量相结合的STE（见步骤2.2），重复步骤2.4在每一个需要的时间点。 </li></ol> 3.后处理分析注意:协议的这一部分包括超声心动图记录图像的评价和解释。它不需要患者存在并且可以在任何时间以下的步骤的前部进行。 <ol><li>利用定量超声心动图分析软件，单击"文件"和"打开"，并选择所需的超声心动图的研究数据。选择一个病人/研究，并挑选应分析超声心动图平面。 </li><li>点击所选图像的右下角的&#39;Q&#39;图标。然后，按左边的"aCMQ"按钮。 </li><li>通过使用绿色的"QRS"跳跃键在屏幕的底部选择了最高图像质量的心动周期。使用键盘空格键播放和暂停循环。 </li><li>选择感兴趣区域（ROI）的区域，以通过确认在屏幕的左侧的超声心动图视图来分析。接下来，让软件自动检测TI舒张末期的明，并提出一个投资回报率。 注:第一个斑点跟踪分析，随后由软件计算的。段及全球ε曲线显示在屏幕的底部。 </li><li>点击下面的图表"应变率"可视化节段性和全球SR。 </li><li>直观地验证了软件提出的质量跟踪。 注:为此，审慎控制是否要分析的心肌的各个方面的投资回报率的心动周期的全部过程中都完全覆盖。避免包括非心肌组织周围到投资回报率。 </li><li>如果需要的话，手动重新定位整个ROI或它的单个方面，甚至完全重新绘制的ROI（见3.8-3.9），以保证准确的测量。 注意:任选地，设置的投资回报率是透明的ROI覆盖调整到心肌的适当位置和宽度。 </li><li>在心尖4，3，2腔心切，拥有软件自动确定一个可能的投资回报率划分成心肌七段。 <ol><li>万一ROI重新定义是必要的，点击"绘制"在左侧，并开始了在三个参考点标记的心内膜边界:将AV阀的两个相对的插入点和左心室壁开始与基础infero-室间隔/基底infero外侧阀门的顶点中心整理/基底下的一部分。保证跟踪-心内膜的两个端点上完全排除瓣膜组织相同的水平。 </li><li>如果重新定位是必要的，以便优化ROI的位置和宽度，点击屏幕左侧的"编辑"。单独移动每个段余量以及心内膜​​和心外膜边界的光标。利用整体移动ROI时指着顶点导航/方向正交线。 </li><li>最后，按启动斑点追踪再分析在屏幕左侧的"计算"按钮。 注:该软件可以自动探测"声学标记"，它对应的偏转心肌纤维组织在其整个运动心肌的收缩和舒张心肌超微结构。这些声学标记通过一个完整的心脏周期的整个持续时间跟踪。必要的计算可能需要几秒到几分钟。 ε和SR被由软件计算，并在一个数字和图形的方式呈现。 </li></ol></li><li>在里面 胸骨旁视图，让软件自动提示预定投资回报率。手动调整这个投资回报率，划分成心肌六个部分。 注:ROI的宽度，应心肌的厚度完全匹配。如有必要，如3.8.2所述优化ROI的位置和宽度。在ROI中心的一个点可以在移动时的投资回报率被用于导航/定位其全文。 <ol><li>接着，通过按下在屏幕左侧的"计算"按钮启动该斑点追踪再分析。 </li></ol></li><li>选择节段性和全球ε和SR要显示在曲线或综合靶心格式。要做到这一点，请点击屏幕左下角的"首选项"按钮。不同类型的波形和显示选项可以在此菜单中选择。 </li><li>如果ROI的手工重新定位是不足以实现适当整体斑点跟踪质量，从3.1开始并重新定义ROI或考虑继续到下一步骤之前，选择一个不同的心动周期。 </li><li>保存并导出数据为后续的统计分析。如果需要的话，电影循环或静止帧可以导出为插图。要做到这一点，请单击"导出"屏幕的左下角，然后选择所需的格式和文件目录。 </li></ol>

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The authors have nothing to disclose.

相对于其他方法的技术意义 目前的金标准左室收缩功能的超声心动图的评估是左室射血分数（EF）13。然而，EF的确定是基于被密切相关心肌收缩的径向分量，但不考虑的重要纵向和圆周平面的简单的方法。因此，EF简单化心肌变形的三维的复杂性。因此，EF测量不揭露细微心脏功能障碍，但只在一个相对先进的状态14检测的LV恶化。另一方面，STE衍生ε和SR已显示检测亚临床心脏改变而EF仍保持正常15。 STE已经出现成为研究和裸重要的临床意义一个强大的工具，提供significan科技进步在心血管病人16的管理。全球LV纵向ε有STE衍生LV变形参数中最高的临床价值相比，周向和径向ε7时更好地反映了全球心肌功能。 纵向ε和SR被在心尖长轴次评估，并重复地评估全球及区域LV的变形（ 图1和2）。注意必须支付维持图像质量和心肌跟踪最高要求的，因为组织追踪产量不足不正确变形参数所证明图3中。周向和径向壁运动可以在胸骨旁短轴定量测定，往往不那么明显（ 图4和5）。尽管全球左室纵向ε已指出作为最显著单STE-DERIVED变形参数，适用于各种临床情况17,18周向和径向室壁运动产量的重要的附加信息。 幸运的是，新的超声心动图设备提供评估几个分钟内，在病人的床边全球纵向ε测量的可能性。这使医生能够执行鲁棒检测的左心室心肌变形参数，而不需要在记录和离线各种横截面超声图像的后处理耗时全面STE-测量的可能性。利用靶心可视化，医生可以一目了然（ 图7）审查全球LV功能。 此外，除了全球左室功能的评估，分段（地区）的心肌功能可以使用STE分析。这使医生来衡量心肌不同步和心脏再响应同步治疗19,20。 局限性，关键步骤和故障排除 尽管STE的有前途的优势，该技术具有重要的限制。首先，超声心动图的图像质量可重复性STE衍生测量的依赖不能被夸大。因此，关键是要特别注意改善图像质量尽可能21。甚至细微工件可以导致ε或SR显著误解，如在图3和6证实。此外，该组织追踪软件自动包括所有部门无论其图像质量。有时，它甚至可能意味着对投资回报不切实际的变形参数，包括非心脏组织。因此，使用全面的视觉评估准确的投资回报率的大小和位置和增量微调的专用验证是绝对必要的。&lt;/ P&gt; 旨在避免超声心动图图像采集过程中文物的另一种方法是向病人保持他/她的呼吸几秒钟。虽然这通常是在主管成年患者常规超声心动图研究是可行的，那肯定是具有挑战性，常常不切实际显然在儿科患者或心脏压力测试期间，如自行车测力去尝试如此。 此外，之前的图像获取的帧速率的优化调整是必需的。每秒结果低于30帧，流畅的过度时间 - 应变曲线和帧速率缺乏足够的时间分辨率。高帧速率超过每秒100帧常常产生噪声的ε曲线是只与极高的图像质量可靠。每秒60至80帧的范围已经建立了最适合于一般的成人患者人群16最佳组织追踪的软件要求。在儿科心脏病特别是在新生儿科，病人自然有更高的心脏利率比成年个体。根据早产儿最近的STE研究中，作者建议根据患者的心脏率调整帧速率设置。每BPM秒0.7〜0.9的帧的帧速率/心脏速率比，提出以达到最佳的心肌斑点跟踪结果22。总之，视图帧或体积速率和图像质量的标准化应该是心肌性能STE衍生评估的先决条件，以实现可靠的，精心重复的结果。 此外，值得注意的是提心肌性能即STE衍生评估目前是一个相当耗时的方法。尽管对于临床决策的有希望的值，该过程的多个步骤的性质，包括许多必要的质量控制和软件计算步骤可能是最相关的廉itation从一天到一天的临床日常护理使用阻碍STE。应该鼓励公司特别注重可行性，以优化组织追踪软件开发，以加快和改进工作流程，使其更加人性化。 最后，STE的一个重要的限制是不同的软件包之间STE衍生ε和SR值的方差。各种商业公司提供STE分析软件，利用不同的底层算法，数学，有时产生非一致的变形参数。因此，一个给定的心肌ε或SR与A公司的设备测量已经谨慎解释时，参考值是从STE软件包B公司的衍生 未来的应用 目前，STE越来越多地用于检测仍受conven未被发现心肌性能的微妙变化TIONAL超声心动图23。而LV已经在不同的STE研究中评估，很少有人仍称为对左心房，右心室和右心房力学的各种临床和科研的情景。新修改的技术甚至允许船只刚度为利用斑点追踪技术大动脉的评估。此外，STE可以在实验动物模型被用于收集有关而不需要侵入性手术心肌性能的有价值的信息。 3D-STE是另一种有发展前景的，允许全面和时间效率心肌变形分析。此外，STE可以用药物或功率自行车压力测试相结合相对于传统的负荷超声心动图的时候能够更好地检测室壁运动异常。此外，心肌扭曲和扭转可评估采用STE，这可能会增加增量的临床价值对全球ε和SR成像。进一步研究AR以便在需要E要阐明两者的临床意义和STE这些潜在影响的局限性。

心血管内科的科学和临床方案是，而不是简单的多，并连续变量和临界值以上处理"是或否"的算法。成像技术已经发展到能够评估在不断增加的细节心脏功能。斑点跟踪超声心动图（STE）是心肌性能的定量评价一个新兴的诊断工具。虽然常规超声心动图是主观影像解译和个人考官的专业知识很强的依赖性有限，STE已被引入作为一个可重复的，更客观的方法来量化全球和区域的收缩和舒张功能1,2。 左心室（LV）心肌变形 - 纵向和圆周缩短以及在收缩和舒张反之亦然径向增厚 - 可被描述测量参数应变（ε）和斯特拉在率（SR）。 ε是在心肌长度的量纲变化百分比。 SR为ε3的时间导数。心肌功能的这些重要指标已显示出能够识别心肌缺血4，预测响应于心脏再同步治疗5和检测亚临床心肌功能障碍而常规超声心动图参数仍然正常6。在系统的荟萃分析，全球纵向ε，最常用的定量左室收缩功能参数，已被证明对主要不良心脏事件的预测则左室射血分数（EF），目前的黄金标准卓越的预后价值左室收缩功能7的评估。即使是很细微的变化，如对无症状患者心肌力学短期代谢变化的影响可以利用STE 8进行检测。 从技术上讲，采用STEš灰度2D或记录在标准的超声心动图的看法3D B模式动态影像。几个连续的心动周期被记录在心尖4-，3-和2-室次测量纵向变形和在周向和径向变形9胸骨旁短轴图。此外，通过在二尖瓣的水平捕获短轴视图，乳头肌和顶点，LV扭转可以评估3。随后向图像采集和存储作为数字环路，心肌变形是在离线的工作站或超声波装置本身上测得。软件检测中所记录的灰度图像独特心肌像素图案，所谓的"斑点"，并跟踪它们在整个分析心动周期。矢量测量和变形参数随后计算。这样的区域和全球心肌变形可以在收缩和舒张用于左和右心室的两者来评估ð庭10。

<table border="0" cellpadding="0" cellspacing="0" width="1299">
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		<col span="2" />
		<col />
	</colgroup>
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:373px;">Phillips iE33 ultrasound system</td>
			<td style="width:155px;">Philips Healthcare</td>
			<td style="width:155px;"></td>
			<td style="width:619px;">http://www.umiultrasound.com/ultrasound-machine/philips/ie33</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:373px;"> 
			S5-1 broadband sector array transducer&#160;</td>
			<td style="width:155px;">Philips Healthcare</td>
			<td style="width:155px;"></td>
			<td>5-1 MHz, http://www.usa.philips.com/healthcare/product/HC989605412081/s5-1</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">QLAB Advanced Quantification Software Version 10.5</td>
			<td style="width:155px;">Philips Healthcare</td>
			<td style="width:155px;"></td>
			<td>Q-App: Automated Cardiac Motion Quantification (aCMQ), www.philips.com/QLAB-cardiology</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Xcelera R3.3L1 (Version 3.3.1.1103)&#160;</td>
			<td style="width:155px;">Philips Healthcare</td>
			<td style="width:155px;"></td>
			<td>http://www.usa.philips.com/healthcare/product/HC830038/xcelera-r41-cardiology-information-management-system</td>
		</tr>
	</tbody>
</table>

transthoracic speckle tracking echocardiography for the quantitative assessment of left ventricular myocardial deformation

常规超声心动图的价值是通过个体间影像解译，因此很大程度上取决于考官的专业知识差异的限制。斑点跟踪超声心动图（STE）是可用于定量评估区域和全球收缩和舒张心肌表现一个有前途的，但技术上的挑战的方法。心肌应变和应变率可以在所有三个维度来测量 - 径向，周向，纵向 - 心肌变形。标准横截面二维B模式图像被记录并随后由心肌内散斑自动化连续帧接一帧的跟踪和运动分析后处理。影像记录数字环路和同步到3导心电图用于定时。纵向变形在心尖4-，3-和2-室次评估。周向和径向的变形是在parasterna测L类短期轴平面。 最佳的图像质量和准确的组织追踪是最重要的正确判断心肌的性能参数。在一个健康的志愿者利用经胸STE，本文章的基本步骤和定量超声心动图心肌变形分析潜在的陷阱的详细大纲。

对于心肌性能的定量评估的原则参数ε和SR。从技术上讲，所有心腔可以用STE进行分析。然而，由于斑点追踪方法大多已经用于研究LV，本文的重点是LV心肌力学。通常，纵向ε和SR是最常用评估左心室变形参数。纵向ε和SR描述心肌收缩期缩短（和舒张压延长）。因此，收缩值被注解为负数。 图1和2表示STE衍生节段性和全球ε和SR分析的好例子。最佳的图像质量和投资回报率的适当组织覆盖是最重要的心肌变形的可靠评估。次优组织追踪经常导致真正的ε和SR值的误解。组织较差的一个例子在心尖（紫色）和中横向（蓝色）的段跟踪质量显示在图3心尖和中间-侧部ε为在一个健康的患者，谁的该实施例很大程度上低估。 -当正确评估-表现出与正常LV变形在所有低压段不起眼的异构ε和SR值。 <img alt="图1" src="/files/ftp_upload/54736/54736fig1.jpg" /> 图1:心尖四腔切面衍生纵向应变和应变率心尖四腔切面（AP4）衍生ε和SR在左，右面板分别给出。每个颜色的时间 - 应变曲线（左，右，下），分别对应于七彩色编码的心肌段（左，右，上）中的一个可视化和节段性（=区域）ε或SR。白色虚线表示全球纵向LVε或SR分别。注意段的顺利平行状时间应变和SR曲线。 <a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/54736/54736fig1large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <img alt="图2" src="/files/ftp_upload/54736/54736fig2.jpg" /> 图2:心尖二腔观衍生纵向应变和应变率左，右侧面板显示心尖二腔（AP2）衍生LV心肌ε和SR分别。时间-应变曲线如以上针对图1描述对应颜色编码段。 <a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/54736/54736fig2large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <img alt="图3" src="/files/ftp_upload/54736/54736fig3.jpg" /> 图3:根尖不足组织追踪:AP2衍生纵向应变这一健康的病人实际工作y具有正常左室心肌ε值，当正确的评估。作为工件，在该图心尖（紫色）和中横向（蓝色）链段表现出差的组织追踪质量，从而真正节段性ε大大低估。山顶LV全球心肌ε值显示（ 图2，右下）。注意:如果没有暗红色的颜色编码，代表了彩色编码曲线M型心肌收缩（ 图2，左下）。 <a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/54736/54736fig3large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> 周ε和SR描述左心室心肌（及其延长舒张）的圆形收缩期缩短，因此被表示为在收缩负数。圆周LV变形在胸骨旁短轴观评估在三个不同的平面:在二尖瓣环的水平，乳头肌（ 图4）和在顶点。所有三个层次的夹杂物产生LV心肌扭转 - 顺时针基底和心尖逆时针旋转收缩期 - 表现为左心室收缩扭曲和舒张无捻。 <img alt="图4" src="/files/ftp_upload/54736/54736fig4.jpg" /> 图4:LV圆周应变乳头肌水平胸骨旁短轴切面得出圆周ε。心肌被细分成六个区段。区域高峰LV周ε值显示在顶部。节段性颜色对应于在底部显示的时间 - 应变曲线。白色虚线表示全球圆周ε。注意节段性和全球时间-应变曲线的光滑和平行的形状。 <a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/54736/54736fig4large.jpg" target="_blank">请cli来</a>这里完蛋查看此图的放大版本。 而纵向和圆周ε是在收缩负，径向ε反映收缩心肌增厚，因此在收缩阳性。一个良好的执行的LV径向ε评估的一个例子是表现在图5相反， 图6示出了前间壁myocar的不正确组织追踪- 。当充分测量-不起眼变形参数。 <img alt="图5" src="/files/ftp_upload/54736/54736fig5.jpg" /> 图5:在乳头肌水平LV径向应变胸骨旁短轴切面也产生径向ε。心肌ROI覆盖在顶部左侧显示。节段性收缩期峰值径向ε值是在左侧的底部呈现（以％表示）。径向时间 - 应变曲线右上方显示图中的一个方面。径向应变显示在％在y轴和时间对应于心电图（在底部）上呈现x轴。彩色曲线M-模式表示正径向ε暗红色是在底部右侧所示。注意相应的井曲线M型彩色编码统一的桡骨ε曲线的形状均匀。 <a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/54736/54736fig5large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <img alt="图6" src="/files/ftp_upload/54736/54736fig6.jpg" /> 图6:不足组织追踪:LV径向应变的概念内容和缩放该图对应于图5在本实施例差间壁组织追踪导致无症状健康患者不精确径向ε值和异构径向时间-应变曲线。注意偏差室间隔（红色）和前间壁（黄色）桡ε曲线。 <a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/54736/54736fig6large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> 对于一个全面的说明，LV心肌纵向ε可以显示在所谓的靶心图（ 图7）。通过这种方式，17段的共占左心室心肌的整体峰值收缩纵向ε值可以在单个视图中被可视化。为AP4-，AP2-和AP3衍生节段性纵向ε时间-应变曲线也示出，对应于彩色编码的概述的图1和2。这说明可能是有利于区域可视化变形变化的赤字，如心肌淀粉样变这在靶心视图的特点是心尖陪练<strong&gt;的信息。 <img alt="图7" src="/files/ftp_upload/54736/54736fig7.jpg" /> 图7:左心室整体应变:靶心视图纵向时间-应变曲线显示从AP4衍生（左上）的LV节段性心肌ε，AP2（右上）和AP3（左下）平面。不同颜色的曲线对应于该段分割为在图1和2表示。纵向ε显示在％上被表示在x轴的y轴和相对时间对应于心电图（在底部）。峰节段性纵向ε值在靶心插图在AP4，AP2和AP3的观点分析17段所描绘（右下）。红色阴影颜色编码对应右侧显示的传说。注意在AP4衍生节段性时间 - 应变曲线的更高的均匀性相比AP2和AP3时。这个Correlates很好地与挑战性的图像采集前左心室壁方面常常导致文物和异构变形参数， <a href="https://ecsource-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/54736/54736fig7large.jpg" target="_blank">请点击这里查看该图的放大版本。</a>

Watch this Scientific Journal Video about Transthoracic Speckle Tracking Echocardiography for the Quantitative Assessment of Left Ventricular Myocardial Deformation at JoVE.com

Transthoracic Speckle Tracking Echocardiography for the Quantitative Assessment of Left Ventricular Myocardial Deformation

斑点跟踪超声心动图是全球和区域心肌的性能定量评估一个新兴的诊断成像技术。标准视图超声心动图的运动图像被记录和变形参数由心肌的B模式图像中散斑的自动化连续帧接一帧的跟踪和运动分析随后测定。

经胸斑点跟踪超声心动图左室心肌变形的定量评价

The value of conventional echocardiography is limited by differences in inter-individual image interpretation and therefore largely dependent on the ...

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Nanyang Technological University

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JoVE Journal

Medicine

19.4K 次观看.  Witten/Herdecke University. 斑点跟踪超声心动图是全球和区域心肌的性能定量评估一个新兴的诊断成像技术。标准视图超声心动图的运动图像被记录和变形参数由心肌的B模式图像中散斑的自动化连续帧接一帧的跟踪和运动分析随后测定。 

视频: Transthoracic Speckle Tracking Echocardiography for the Quantitative Assessment of Left Ventricular Myocardial Deformation

Transthoracic Echocardiography in Mice

In recent years, murine models have become the primary avenue for studying the molecular mechanisms of cardiac dysfunction resulting from changes in gene expression. Transgenic and gene targeting methods can be used to generate mice with altered cardiac size and function,1-3 and as a result, in vivo techniques are needed to evaluate their cardiac phenotype. Transthoracic echocardiography, pulse wave Doppler (PWD), and tissue Doppler imaging (TDI) can be used to provide dimensional measurements of the mouse heart and to quantify the degree of cardiac systolic and diastolic performance. Two-dimensional imaging is used to detect abnormal anatomy or movements of the left ventricle, whereas M-mode echo is used for quantification of cardiac dimensions and contractility.4,5 In addition, PWD is used to quantify localized velocity of turbulent flow,6 whereas TDI is used to measure the velocity of myocardial motion.7 Thus, transthoracic echocardiography offers a comprehensive method for the noninvasive evaluation of cardiac function in mice.

Transthoracic echocardiography offers a noninvasive method for the evaluation of cardiac function in mice. A combination of ultrasound and Doppler imaging modalities can be used to obtain dimensional measurements of the heart and intracardiac blood flow, which together provide an assessment of cardiac systolic and diastolic performance.

经胸超声心动图在小鼠

In recent years, murine models have become the primary avenue for studying the molecular mechanisms of cardiac dysfunction resulting from changes in gene ...

科研

医学

Magnetic Resonance Derived Myocardial Strain Assessment Using Feature Tracking

Purpose: An accurate and practical method to measure parameters like strain in myocardial tissue is of great clinical value, since it has been shown, that strain is a more sensitive and earlier marker for contractile dysfunction than the frequently used parameter EF. Current technologies for CMR are time consuming and difficult to implement in clinical practice. Feature tracking is a technology that can lead to more automization and robustness of quantitative analysis of medical images with less time consumption than comparable methods.
Methods: An automatic or manual input in a single phase serves as an initialization from which the system starts to track the displacement of individual patterns representing anatomical structures over time. The specialty of this method is that the images do not need to be manipulated in any way beforehand like e.g. tagging of CMR images.
Results: The method is very well suited for tracking muscular tissue and with this allowing quantitative elaboration of myocardium and also blood flow.
Conclusions: This new method offers a robust and time saving procedure to quantify myocardial tissue and blood with displacement, velocity and deformation parameters on regular sequences of CMR imaging. It therefore can be implemented in clinical practice.

An accurate and practical method to measure parameters like strain in myocardial tissue is of great clinical value, since it has been shown, that strain is a more sensitive and earlier marker for contractile dysfunction than the frequently used parameter EF.

磁共振衍生的心肌劳损评估使用特征跟踪

Purpose: An accurate and practical method to measure parameters like strain in myocardial tissue is of great clinical value, since it has been shown, that ...

Ultrasonic Assessment of Myocardial Microstructure

Echocardiography is a widely accessible imaging modality that is commonly used to noninvasively characterize and quantify changes in cardiac structure and function. Ultrasonic assessments of cardiac tissue can include analyses of backscatter signal intensity within a given region of interest. Previously established techniques have relied predominantly on the integrated or mean value of backscatter signal intensities, which may be susceptible to variability from aliased data from low frame rates and time delays for algorithms based on cyclic variation. Herein, we describe an ultrasound-based imaging algorithm that extends from previous methods, can be applied to a single image frame&#160;and accounts for the full distribution of signal intensity values derived from a given myocardial sample. When applied to representative mouse and human imaging data, the algorithm distinguishes between subjects with and without exposure to chronic afterload resistance. The algorithm offers an enhanced surrogate measure of myocardial microstructure and can be performed using open-access image analysis software.

Echocardiography is commonly used to noninvasively characterize and quantify changes in cardiac structure and function. We describe an ultrasound-based imaging algorithm that offers an enhanced surrogate measure of myocardial microstructure and can be performed using open-access image analysis software.

心肌微观结构超声波评估

Echocardiography is a widely accessible imaging modality that is commonly used to noninvasively characterize and quantify changes in cardiac structure and ...

Assessment of Right Ventricular Structure and Function in Mouse Model of Pulmonary Artery Constriction by Transthoracic Echocardiography

Emerging clinical data support the notion that RV dysfunction is critical to the pathogenesis of cardiovascular disease and heart failure1-3. Moreover, the RV is significantly affected in pulmonary diseases such as pulmonary artery hypertension (PAH). In addition, the RV is remarkably sensitive to cardiac pathologies, including left ventricular (LV) dysfunction, valvular disease or RV infarction4. To understand the role of RV in the pathogenesis of cardiac diseases, a reliable and noninvasive method to access the RV structurally and functionally is essential.
A noninvasive trans-thoracic echocardiography (TTE) based methodology was established and validated for monitoring dynamic changes in RV structure and function in adult mice. To impose RV stress, we employed a surgical model of pulmonary artery constriction (PAC) and measured the RV response over a 7-day period using a high-frequency ultrasound microimaging system. Sham operated mice were used as controls. Images were acquired in lightly anesthetized mice at baseline (before surgery), day 0 (immediately post-surgery), day 3, and day 7 (post-surgery). Data was analyzed offline using software.
Several acoustic windows (B, M, and Color Doppler modes), which can be consistently obtained in mice, allowed for reliable and reproducible measurement of RV structure (including RV wall thickness, end-diastolic&#160;and end-systolic dimensions), and function (fractional area change, fractional shortening, PA peak velocity, and peak pressure gradient) in normal mice and following PAC.
Using this method, the pressure-gradient resulting from PAC was accurately measured in real-time using Color Doppler mode and was comparable to direct pressure measurements performed with a Millar high-fidelity microtip catheter. Taken together, these data demonstrate that RV measurements obtained from various complimentary views using echocardiography are reliable, reproducible and can provide insights regarding RV structure and function. This method will enable a better understanding of the role of RV cardiac dysfunction.

Right ventricle (RV) dysfunction is critical to the pathogenesis of cardiovascular disease, yet limited methodologies are available for its evaluation. Recent advances in ultrasound imaging provide a noninvasive and accurate option for longitudinal RV study. Herein, we detail a step-by-step echocardiographic method using a murine model of RV pressure overload.

右心室结构和功能的肺动脉缩窄经胸超声小鼠模型的评估

Emerging clinical data support the notion that RV dysfunction is critical to the pathogenesis of cardiovascular disease and heart failure1-3. Moreover, ...

Myocardial Infarction and Functional Outcome Assessment in Pigs

Introduction of newly discovered cardiovascular therapeutics into first-in-man trials depends on a strictly regulated ethical and legal roadmap. One important prerequisite is a good understanding of all safety and efficacy aspects obtained in a large animal model that validly reflect the human scenario of myocardial infarction (MI). Pigs are widely used in this regard since their cardiac size, hemodynamics, and coronary anatomy are close to that of humans. Here, we present an effective protocol for using the porcine MI model using a closed-chest coronary balloon occlusion of the left anterior descending artery (LAD), followed by reperfusion. This approach is based on 90 min of myocardial ischemia, inducing large left ventricle infarction of the anterior, septal and inferoseptal walls. Furthermore, we present protocols for various measures of outcome that provide a wide range of information on the heart, such as cardiac systolic and diastolic function, hemodynamics, coronary flow velocity, microvascular resistance, and infarct size. This protocol can be easily tailored to meet study specific requirements for the validation of novel cardioregenerative biologics at different stages (i.e. directly after the acute ischemic insult, in the subacute setting or even in the chronic MI once scar formation has been completed). This model therefore provides a useful translational tool to study MI, subsequent adverse remodeling, and the potential of novel cardioregenerative agents.

This protocol describes the porcine myocardial infarction (MI) model using a 90 min closed-chest coronary balloon occlusion of the left anterior descending artery (LAD), followed by reperfusion. Furthermore, the protocol for several outcome parameters, such as cardiac function, hemodynamics, microvascular resistance, and infarct size, are also presented.

心肌梗死和功能预后评估的猪

Introduction of newly discovered cardiovascular therapeutics into first-in-man trials depends on a strictly regulated ethical and legal roadmap. One ...

A Murine Model of Myocardial Ischemia-reperfusion Injury through Ligation of the Left Anterior Descending Artery

Acute or chronic myocardial infarction (MI) are cardiovascular events resulting in high morbidity and mortality. Establishing the pathological mechanisms at work during MI and developing effective therapeutic approaches requires methodology to reproducibly simulate the clinical incidence and reflect the pathophysiological changes associated with MI. Here, we describe a surgical method to induce MI in mouse models that can be used for short-term ischemia-reperfusion (I/R) injury as well as permanent ligation. The major advantage of this method is to facilitate location of the left anterior descending artery (LAD) to allow for accurate ligation of this artery to induce ischemia in the left ventricle of the mouse heart. Accurate positioning of the ligature on the LAD increases reproducibility of infarct size and thus produces more reliable results. Greater precision in placement of the ligature will improve the standard surgical approaches to simulate MI in mice, thus reducing the number of experimental animals necessary for statistically relevant studies and improving our understanding of the mechanisms producing cardiac dysfunction following MI. This mouse model of MI is also useful for the preclinical testing of treatments targeting myocardial damage following MI.

We introduce a surgical method to induce experimental ischemia/reperfusion (I/R) injury to simulate myocardial infarction (MI) in mouse models that allows for more clarity in positioning of the ligation on the left anterior descending artery (LAD) to increase the reproducibility of MI experiments in mice.

心肌缺血再灌注损伤的通过左前降支结扎小鼠模型

Acute or chronic myocardial infarction (MI) are cardiovascular events resulting in high morbidity and mortality. Establishing the pathological mechanisms ...

Murine Echocardiography of Left Atrium, Aorta, and Pulmonary Artery

The present methodology teaches the investigator how to measure and use the LAV as a surrogate of chronic elevations in Left Ventricular diastolic pressure through echocardiography, as well as to obtain measurements of the Aorta and PA diameter in mice.
Mice older than 10 d of age can be analyzed using the present technique. The technique is composed of 3 main steps: set-up, image acquisition, and image analysis. The set-up step consists of getting the mouse anesthetized with 1% isoflurane, shaving it, and taping it in a supine position to a heated EKG board where the image acquisition will take place. The image acquisition step consists of learning to identify the cardiac structures and obtaining all the required images with its correspondent probe and axis in order to be able to calculate volumes and diameters. The image analysis step consists of measuring the previously acquired images with the aid of computer software.
Advantages of the proposed technique include a fast (15 min) procedure that would allow the researcher to evaluate interventions in a non-invasive, non-terminal approach and therefore follow the same mouse over time; each mouse can be used as its own control. This fact plus having the same operator perform all the acquisition and analysis for the entire experiment minimizes the limitation of operator-dependency. The present methodology is useful for mouse researchers in cardiovascular and pulmonary medicine.

The following protocol describes the methodology for the acquisition and analysis of echocardiographic images used to obtain the Left Atrial Volume (LAV), Aorta (Ao) diameter, and Pulmonary Artery (PA) diameter in mice. This technique is a non-invasive, non-terminal procedure that allows assessment of the cardiopulmonary function.

左心房，主动脉和肺动脉的超声心动图小鼠

The present methodology teaches the investigator how to measure and use the LAV as a surrogate of chronic elevations in Left Ventricular diastolic ...

Technique of Minimally Invasive Transverse Aortic Constriction in Mice for Induction of Left Ventricular Hypertrophy

Transverse aortic constriction (TAC) in mice is one of the most commonly used surgical techniques for experimental investigation of pressure overload-induced left ventricular hypertrophy (LVH) and its progression to heart failure. In the majority of the reported investigations, this procedure is performed with intubation and ventilation of the animal which renders it demanding and time-consuming and adds to the surgical burden to the animal. The aim of this protocol is to describe a simplified technique of minimally invasive TAC without intubation and ventilation of mice. Critical steps of the technique are emphasized in order to achieve low mortality and high efficiency in inducing LVH.
Male C57BL/6 mice (10-week-old, 25-30 g, n=60) were anesthetized with a single intraperitoneal injection of a mixture of ketamine and xylazine. In a spontaneously breathing animal following a 3-4 mm upper partial sternotomy, a segment of 6/0 silk suture threaded through the eye of a ligation aid was passed under the aortic arch and tied over a blunted 27-gauge needle. Sham-operated animals underwent the same surgical preparation but without aortic constriction. The efficacy of the procedure in inducing LVH is attested by a significant increase in the heart/body weight ratio. This ratio is obtained at days 3, 7, 14 and 28 after surgery (n = 6 - 10 in each group and each time point). Using our technique, LVH is observed in TAC compared to sham animals from day 7 through day 28. Operative and late (over 28 days) mortalities are both very low at 1.7%.
In conclusion, our cost-effective technique of minimally invasive TAC in mice carries very low operative and post-operative mortalities and is highly efficient in inducing LVH. It simplifies the operative procedure and reduces the strain put on the animal. It can be easily performed by following the critical steps described in this protocol.

The aim of this protocol is to describe step-by-step the technique of minimally invasive transverse aortic constriction (TAC) in mice. By elimination of intubation and ventilation which are mandatory for the commonly used standard procedure, minimally invasive TAC simplifies the operative procedure and reduces the strain put on the animal.

小鼠横主动脉狭窄诱导左心室肥厚的技术研究

Transverse aortic constriction (TAC) in mice is one of the most commonly used surgical techniques for experimental investigation of pressure ...

Studying Left Ventricular Reverse Remodeling by Aortic Debanding in Rodents

To better understand the left ventricular (LV) reverse remodeling (RR), we describe a rodent model wherein, after aortic banding-induced LV remodeling, mice undergo RR upon removal of the aortic constriction. In this paper, we describe a step-by-step procedure to perform a minimally invasive surgical aortic debanding in mice. Echocardiography was subsequently used to assess the degree of cardiac hypertrophy and dysfunction during LV remodeling and RR and to determine the best timing for aortic debanding. At the end of the protocol, terminal hemodynamic evaluation of the cardiac function was conducted, and samples were collected for histological studies. We showed that debanding is associated with surgical survival rates of 70-80%. Moreover, two weeks after debanding, the significant reduction of ventricular afterload triggers the regression of ventricular hypertrophy (~20%) and fibrosis (~26%), recovery of diastolic dysfunction as assessed by the normalization of left ventricular filling and end-diastolic pressures (E/e&#39;&#160;and LVEDP). Aortic debanding is a useful experimental model to study LV RR in rodents. The extent of myocardial recovery is variable between subjects, therefore, mimicking the diversity of RR that occurs in the clinical context, such as aortic valve replacement. We conclude that the aortic banding/debanding model represents a valuable tool to unravel novel insights into the mechanisms of RR, namely the regression of cardiac hypertrophy and the recovery of diastolic dysfunction.

Here we describe a step-by-step protocol of surgical aorta debanding in the well-established mice model of aortic-constriction. This procedure not only allows studying the mechanisms underlying the left ventricular reverse remodeling and regression of hypertrophy but also to test novel therapeutic options that might accelerate myocardial recovery.

研究左心室反向改造由主动脉脱体在啮齿动物

To better understand the left ventricular (LV) reverse remodeling (RR), we describe a rodent model wherein, after aortic banding-induced LV remodeling, ...

Morphological and Functional Assessment of the Right Ventricle Using 3D Echocardiography

Traditionally, it was believed that the right side of the heart has a minor role in circulation; however, more and more data suggest that right ventricular (RV) function has strong diagnostic and prognostic power in various cardiovascular disorders. Due to its complex morphology and function, assessment of the RV by conventional two-dimensional echocardiography is limited: the everyday clinical practice usually relies on simple linear dimensions and functional measures. Three-dimensional (3D) echocardiography overcame these limitations by providing volumetric quantification of the RV free of geometrical assumptions. Here, we offer a step-by-step guide to obtain and analyze 3D echocardiographic data of the RV using the leading commercially available software. We will quantify 3D RV volumes and ejection fraction. Several technical aspects may help to improve the quality of RV acquisition and analysis as well, which we present in a practical manner. We review the current opportunities and the limiting factors of this method and also highlight the potential applications of 3D RV assessment in current clinical practice.

Here, we provide a step-by-step acquisition and analysis protocol for the 3D volumetric assessment of the right ventricle, mainly focusing on the practical aspects that maximize the feasibility of this technique.