我们非常感谢哈佛医学院/布里格姆和妇女医院心血管生理学核心实验室提供的资源。这项工作的部分资金来自国家卫生研究院赠款HL088533、HL071775、HL093148和HL099073（RL）。MB 是美国心脏协会创始人联盟博士后奖学金的获得者。KU 是美国心脏协会创始人附属博士后奖学金的获得者。SC 得到了埃里森基金会的奖励。

1. 分析图像的准备
<ol><li>在半轴视图中获取穆林或人类超心电图 B 模式图像。根据通常的做法，调整时间收益补偿设置和传输焦点的放置，以优化 LV 和其他心脏结构在参数视图中的可视化。确保以 DICOM 文件格式保存所有图像。标准化的图像视图将推理左心室壁置于框架底部。框架必须显示整个左心室心肌和心肌。分辨率必须足够高，以划定左心室的腹腔边界、心肌壁和心内壁。丢弃具有过量辍学或图像神器的图像。</li>
	<li>将图像文件导入图像J软件平台v1.46作为DICOM文件进行分析。将文件转换为 8 位图像文件。</li>
	<li>滚动浏览心脏周期的连续帧，直到达到适当的质量末期舒张框架。或者，在回声心动图查看程序中选择末端舒张帧，然后导入高分辨率.jpg文件格式，供 ImageJ 使用。使用心电图跟踪的 R 波识别最接近末端硅胶的帧，然后识别捕获 LV 的最大内部维度的单个最佳帧。将此单帧视为末端舒张框架。</li>
	<li>建议用户在选择感兴趣的区域时，不要盲目使用主题标识。</li>
</ol>2. 投资回报率抽样
<ol><li>围网参考选择。在选择感兴趣的围产区 （ROI） 时，旨在捕捉围膜组织的异质性。请注意，图像亮度和对比度可根据需要根据需要进行投资回报率选择调整，但不会对分析结果产生任何影响。<ol>
<li>使用 ImageJ 的矩形绘图工具，选择长度接近基底推理围墙中间三分之一的矩形。</li>
		<li>调整矩形投资回报率，使用投资回报率大小工具跨越环形的宽度。</li>
		<li>使用 ImageJ 的旋转工具将投资回报率旋转到围网区域内。</li>
		<li>对围网投资回报率的各个角落进行必要的调整。捕获位于心周壁中间三分之一内的最终心周区域，包括围墙的宽度，而不会延伸到心肌或心脏外区域。旨在为给定研究中提出的所有测量捕获相同的相对位置和总围网面积百分比。</li>
		<li>通过 ImageJ 分析工具将算法应用到选择中（参见第 3 节）。</li>
	</ol>
</li>
	<li>心肌选择。再次，旨在捕捉心肌组织在基底推断心肌壁中间三分之一内的异质性。请注意，图像亮度和对比度可根据需要根据需要进行投资回报率选择调整，但不会对分析结果产生任何影响。<ol>
<li>选择横跨心肌壁宽度的矩形，不包括心内膜和心内膜。确保心肌选择位于腹肌选择的旁边，并处于相同的角度。不包括选择区域内的乳骨肌肉区域。</li>
		<li>旋转心肌投资回报率，使其与心肌选择平行。</li>
		<li>对心肌投资回报率的各个角落进行必要的调整。隔离位于心肌壁中间三分之一的最终心肌区域，并捕获墙的宽度，而不会延伸到心腹或内线区域。</li>
		<li>通过 ImageJ 宏将算法应用于选择。</li>
	</ol>
</li>
</ol>3. 数据分析和处理
<ol><li>安装名为"获取希图值.txt"的图像J宏。</li>
	<li>使用 ImageJ 直方图分析工具预览投资回报率内信号强度值的分布（执行此步骤进行心周选择和心肌选择）。</li>
	<li>使用 ImageJ 宏记录这些信号密度值用于投资回报率（执行此步骤进行心周选择和心肌选择）。<ol>
<li>将强度值从 0（最暗）分配到 255（最亮）单位到选择中的每个像素。</li>
		<li>按增加强度的顺序分层排列强度值，以产生信号强度的分布。</li>
		<li>选择并报告分布的以下百分位数值：20百分位、50百分位（中位数）和 80百分位数。</li>
	</ol>
</li>
	<li>使用心周参考使心肌梗塞正常化。<ol>
<li>通过将心肌百分位数的强度值除以强度12的相应心周百分位数值，或从强度13的心肌百分位数值中减去心肌百分位数值来正常化。</li>
		<li>报告四种分析方法的值：使第 20 个百分位、50 个百分位（中位数）和 80 个百分位数的心肌到心电值正常化。</li>
	</ol>
</li>
</ol>4. 量化周期性变异性
<ol><li>通过 DICOM 文件的连续帧将算法应用于心肌选择，在心脏循环中移动。比较帧之间的强度分布差异，并注意末收缩和末端舒张帧。 上述所有图像分析均在以前以 DICOM 格式获取和数字存储的非侵入性超声心动图图像上离线进行。所有研究协议均由布里格姆和妇女机构审查委员会和哈佛医学区常设机构动物护理和使用委员会批准。</li>
</ol>

<ol>
	<li>Yamada, S., Komuro, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Integrated+backscatter+for+the+assessment+of+myocardial+viability.">Integrated backscatter for the assessment of myocardial viability.</a> Curr. Opin. Cardiol. 21, 433-437 (2006).</li><li>Mimbs, J. W., O'Donnell, M., Bauwens, D., Miller, J. W., Sobel, B. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+dependence+of+ultrasonic+attenuation+and+backscatter+on+collagen+content+in+dog+and+rabbit+hearts.">The dependence of ultrasonic attenuation and backscatter on collagen content in dog and rabbit hearts.</a> Circ. Res. 47, 49-58 (1980).</li><li>Picano, E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vivo+quantitative+ultrasonic+evaluation+of+myocardial+fibrosis+in+humans.">In vivo quantitative ultrasonic evaluation of myocardial fibrosis in humans.</a> Circulation. 81, 58-64 (1990).</li><li>Mizuno, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Myocardial+ultrasonic+tissue+characterization+for+estimating+histological+abnormalities+in+hypertrophic+cardiomyopathy:+comparison+with+endomyocardial+biopsy+findings.">Myocardial ultrasonic tissue characterization for estimating histological abnormalities in hypertrophic cardiomyopathy: comparison with endomyocardial biopsy findings.</a> Cardiology. 96, 16-23 (2001).</li><li>Mizuno, R., Fujimoto, S., Saito, Y., Nakamura, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Non-invasive+quantitation+of+myocardial+fibrosis+using+combined+tissue+harmonic+imaging+and+integrated+backscatter+analysis+in+dilated+cardiomyopathy.">Non-invasive quantitation of myocardial fibrosis using combined tissue harmonic imaging and integrated backscatter analysis in dilated cardiomyopathy.</a> Cardiology. 108, 11-17 (2007).</li><li>Marini, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cyclic+variation+in+myocardial+gray+level+as+a+marker+of+viability+in+man.+A+videodensitometric+study.">Cyclic variation in myocardial gray level as a marker of viability in man. A videodensitometric study.</a> Eur. Heart. J. 17, 472-479 (1996).</li><li>Komuro, K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sensitive+detection+of+myocardial+viability+in+chronic+coronary+artery+disease+by+ultrasonic+integrated+backscatter+analysis.">Sensitive detection of myocardial viability in chronic coronary artery disease by ultrasonic integrated backscatter analysis.</a> J. Am. Soc. Echocardiogr. 18, 26-31 (2005).</li><li>Ciulla, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Echocardiographic+patterns+of+myocardial+fibrosis+in+hypertensive+patients:+endomyocardial+biopsy+versus+ultrasonic+tissue+characterization.">Echocardiographic patterns of myocardial fibrosis in hypertensive patients: endomyocardial biopsy versus ultrasonic tissue characterization.</a> J. Am. Soc. Echocardiogr. 10, 657-664 (1997).</li><li>Maceira, A. M., Barba, J., Varo, N., Beloqui, O., Diez, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultrasonic+backscatter+and+serum+marker+of+cardiac+fibrosis+in+hypertensives.">Ultrasonic backscatter and serum marker of cardiac fibrosis in hypertensives.</a> Hypertension. 39, 923-928 (2002).</li><li>D'Hooge, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High+frame+rate+myocardial+integrated+backscatter.+Does+this+change+our+understanding+of+this+acoustic+parameter.">High frame rate myocardial integrated backscatter. Does this change our understanding of this acoustic parameter.</a> Eur. J. Echocardiogr. 1, 32-41 (2000).</li><li>Finch-Johnston, A. E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cyclic+variation+of+integrated+backscatter:+dependence+of+time+delay+on+the+echocardiographic+view+used+and+the+myocardial+segment+analyzed.">Cyclic variation of integrated backscatter: dependence of time delay on the echocardiographic view used and the myocardial segment analyzed.</a> J. Am. Soc. Echocardiogr. 13, 9-17 (2000).</li><li>Di Bello, V., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Increased+echodensity+of+myocardial+wall+in+the+diabetic+heart:+an+ultrasound+tissue+characterization+study.">Increased echodensity of myocardial wall in the diabetic heart: an ultrasound tissue characterization study.</a> J. Am. Coll. Cardiol. 25, 1408-1415 (1995).</li><li>Takiuchi, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Quantitative+ultrasonic+tissue+characterization+can+identify+high-risk+atherosclerotic+alteration+in+human+carotid+arteries.">Quantitative ultrasonic tissue characterization can identify high-risk atherosclerotic alteration in human carotid arteries.</a> Circulation. 102, 766-770 (2000).</li><li>Querejeta, R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Serum+carboxy-terminal+propeptide+of+procollagen+type+I+is+a+marker+of+myocardial+fibrosis+in+hypertensive+heart+disease.">Serum carboxy-terminal propeptide of procollagen type I is a marker of myocardial fibrosis in hypertensive heart disease.</a> Circulation. 101, 1729-1735 (2000).</li></ol>

未声明任何利益冲突。

我们描述图像分析算法的协议，该算法量化声像信号强度分布，进而提供心肌微观结构的替代测量。协议的标准化功能，包括投资回报率和参考区域的选择、大小和定位，有助于最大限度地减少用户和基于主题的变异性。我们证明，当应用于末期舒张单帧回声心电图图像时，该算法可以适当区分正常心肌与暴露在后负荷应力中的心肌。
该协议详细说明了如何使用开源图像J软?...

心电图是一种广泛访问的成像方式，通常用于非侵入性地描述和量化心脏结构和功能的变化。对心脏组织的超声波评估可以包括在特定时间点以及心脏周期过程中分析特定感兴趣区域内的背散射信号强度。先前的研究表明，测得声像信号强度可以识别心肌纤维混乱、可行与不可行心肌组织以及间质纤维化1-3的基本存在。我们称心肌"微结构"为组织结构，可以使用声学分析进行特征，超越毛额和形态的线性测量。因此，对声像信号强度的分析用于评估心肌组织在肥大和扩张性心肌病4，5，慢性冠状动脉疾病6，7和高血压心脏病8，9的设置的微结构变化。然而，先前建立的技术主要依赖于反散射信号强性的综合值或平均值，这可能容易受到随机噪声5、低帧速率10的别名数据以及基于周期变异11的算法的时间延迟的影响。
本文介绍了使用超声波图像分析算法的方法，该算法从以前的方法延伸至过去：此算法侧重于用于图像分析的单个末端舒张框架，并说明从给定心肌样本中提取的信号强度值的完整分布。该算法使用围网作为帧内参考12，13，可重复量化声学信号强度分布的变化，并提供心肌微观结构的增强替代测量。在分步协议中，我们描述了在选定的感兴趣区域内准备用于使用的图像、取样感兴趣区域和处理数据的方法。我们还展示了应用该算法从小鼠和人类那里获得的回声心电图图像的代表性结果，这些图像可对左心室的后负荷应力进行可变暴露。

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			<td height="21" style="height:21px;width:216px;">ImageJ v 1.46</td>
			<td style="width:268px;">NIH (Bethesda, MD)</td>
			<td style="width:119px;"></td>
			<td style="width:167px;">open access software</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Power ShowCase</td>
			<td style="width:268px;">Trillium Technology (Ann Arbor, MI)</td>
			<td style="width:119px;"></td>
			<td>commercial software</td>
		</tr>
	</tbody>
</table>

ultrasonic assessment of myocardial microstructure

心电图是一种广泛访问的成像方式，通常用于非侵入性地描述和量化心脏结构和功能的变化。对心脏组织的超声波评估可以包括对特定感兴趣区域内的背散射信号强度的分析。以前建立的技术主要依赖于反散射信号强性的集成值或平均值，这可能容易受到基于周期变化的算法的低帧速率和算法时间延迟的别名数据的变异性的影响。在此，我们描述了一种基于超声波的成像算法，该算法从以前的方法扩展到单个图像帧，并说明从给定心肌样本中提取的信号强度值的完整分布。当应用于具有代表性的鼠标和人类成像数据时，该算法区分有或不暴露于慢性后置阻力的受试者。该算法提供了心肌微观结构的增强替代测量，可使用开放访问图像分析软件执行。

信号强度分析主要包括4个主要步骤（图1），包括：1）图像选择和格式，2）采样投资回报率和参考区域，3）算法应用，4）处理最终值，以产生心肌与心肌强度比。投资回报率的选择和大小标准化，以限制互用器以及内部使用者变异性（图 2）。每个投资回报率的定位也标准化，针对每个主体的解剖结构，以限制主体间和主体内部的变异性。
作为心?...

Watch this Scientific Journal Video about Ultrasonic Assessment of Myocardial Microstructure at JoVE.com

Ultrasonic Assessment of Myocardial Microstructure

回声心动图通常用于非侵入性地描述和量化心脏结构和功能的变化。我们描述了一种基于超声波的成像算法，该算法提供了心肌微观结构的增强替代测量，并且可以使用开放访问图像分析软件执行。

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 ...

ultrasonic-assessment-of-myocardial-microstructure

Research

JoVE Journal

Medicine

5.3K 次观看.  Harvard Medical School. 回声心动图通常用于非侵入性地描述和量化心脏结构和功能的变化。我们描述了一种基于超声波的成像算法，该算法提供了心肌微观结构的增强替代测量，并且可以使用开放访问图像分析软件执行。

视频: Ultrasonic Assessment of Myocardial Microstructure

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 ...

科研

医学

Acute Myocardial Infarction in Rats

With heart failure leading the cause of death in the USA (Hunt), biomedical research is fundamental to advance medical treatments for cardiovascular diseases. Animal models that mimic human cardiac disease, such as myocardial infarction (MI) and ischemia-reperfusion (IR) that induces heart failure as well as pressure-overload (transverse aortic constriction) that induces cardiac hypertrophy and heart failure (Goldman and Tarnavski), are useful models to study cardiovascular disease. In particular, myocardial ischemia (MI) is a leading cause for cardiovascular morbidity and mortality despite controlling certain risk factors such as arteriosclerosis and treatments via surgical intervention (Thygesen). Furthermore, an acute loss of the myocardium following myocardial ischemia (MI) results in increased loading conditions that induces ventricular remodeling of the infarcted border zone and the remote non-infarcted myocardium. Myocyte apoptosis, necrosis and the resultant increased hemodynamic load activate multiple biochemical intracellular signaling that initiates LV dilatation, hypertrophy, ventricular shape distortion, and collagen scar formation. This pathological remodeling and failure to normalize the increased wall stresses results in progressive dilatation, recruitment of the border zone myocardium into the scar, and eventually deterioration in myocardial contractile function (i.e. heart failure). The progression of LV dysfunction and heart failure in rats is similar to that observed in patients who sustain a large myocardial infarction, survive and subsequently develops heart failure (Goldman). The acute myocardial infarction (AMI) model in rats has been used to mimic human cardiovascular disease; specifically used to study cardiac signaling mechanisms associated with heart failure as well as to assess the contribution of therapeutic strategies for the treatment of heart failure. The method described in this report is the rat model of acute myocardial infarction (AMI). This model is also referred to as an acute ischemic cardiomyopathy or ischemia followed by reperfusion (IR); which is induced by an acute 30-minute period of ischemia by ligation of the left anterior descending artery (LAD) followed by reperfusion of the tissue by releasing the LAD ligation (Vasilyev and McConnell). This protocol will focus on assessment of the infarct size and the area-at-risk (AAR) by Evan's blue dye and triphenyl tetrazolium chloride (TTC) following 4-hours of reperfusion; additional comments toward the evaluation of cardiac function and remodeling by modifying the duration of reperfusion, is also presented. Overall, this AMI rat animal model is useful for studying the consequence of a myocardial infarction on cardiac pathophysiological and physiological function.

The rat model of acute myocardial infarction (AMI) is useful to study the consequence of a MI on cardiac pathophysiological and physiological function.

大鼠急性心肌梗死

With heart failure leading the cause of death in the USA (Hunt), biomedical research is fundamental to advance medical treatments for cardiovascular ...

Assessment of Cardiac Function and Myocardial Morphology Using Small Animal Look-locker Inversion Recovery (SALLI) MRI in Rats

Small animal magnetic resonance imaging is an important tool to study cardiac function and changes in myocardial tissue. The high heart rates of small animals (200 to 600 beats/min) have previously limited the role of CMR imaging. Small animal Look-Locker inversion recovery (SALLI) is a T1 mapping sequence for small animals to overcome this problem 1. T1 maps provide quantitative information about tissue alterations and contrast agent kinetics. It is also possible to detect diffuse myocardial processes such as interstitial fibrosis or edema 1-6. Furthermore, from a single set of image data, it is possible to examine heart function and myocardial scarring by generating cine and inversion recovery-prepared late gadolinium enhancement-type MR images 1.
	The presented video shows step-by-step the procedures to perform small animal CMR imaging. Here it is presented with a healthy Sprague-Dawley rat, however naturally it can be extended to different cardiac small animal models.

Assessment of Cardiac Function and Myocardial Morphology Using Small Animal Look-locker Inversion Recovery SALLI MRI in Rats

Contrast enhanced cardiac magnetic resonance (CMR) imaging allows comprehensive in vivo assessment of the heart in small animal models of cardiovascular disease. Here we detail the procedures to perform CMR imaging, reconstruction and analysis using Small Animal Lock-Locker Inversion Recovery (SALLI) in rats.

使用小动物看更衣室反转恢复（SALLI）的MRI大鼠心脏功能和心肌形态学评估

Small animal magnetic resonance  imaging is an important tool to study cardiac function and changes in myocardial  tissue. The high heart rates of small ...

MRI and PET in Mouse Models of Myocardial Infarction

Myocardial infarction is one of the leading causes of death in the Western world. The similarity of the mouse heart to the human heart has made it an ideal model for testing novel therapeutic strategies.
In vivo magnetic resonance imaging (MRI) gives excellent views of the heart noninvasively with clear anatomical detail, which can be used for accurate functional assessment. Contrast agents can provide basic measures of tissue viability but these are nonspecific. Positron emission tomography (PET) is a complementary technique that is highly specific for molecular imaging, but lacks the anatomical detail of MRI. Used together, these techniques offer a sensitive, specific and quantitative tool for the assessment of the heart in disease and recovery following treatment.
In this paper we explain how these methods are carried out in mouse models of acute myocardial infarction. The procedures described here were designed for the assessment of putative protective drug treatments. We used MRI to measure systolic function and infarct size with late gadolinium enhancement, and PET with fluorodeoxyglucose (FDG) to assess metabolic function in the infarcted region. The paper focuses on practical aspects such as slice planning, accurate gating, drug delivery, segmentation of images, and multimodal coregistration. The methods presented here achieve good repeatability and accuracy maintaining a high throughput.

We describe how to perform MRI and PET imaging of the mouse heart. The protocol is tailored to assess treatment efficacy in models of myocardial infarction and heart failure.

MRI和PET心肌梗死小鼠模型

Myocardial infarction is one of the leading causes of death in the Western world. The similarity of the mouse heart to the human heart has made it an ...

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 ...

Primary Outcome Assessment in a Pig Model of Acute Myocardial Infarction

Mortality after acute myocardial infarction remains substantial and is associated with significant morbidity, like heart failure. Novel therapeutics are therefore required to confine cardiac damage, promote survival and reduce the disease burden of heart failure. Large animal experiments are an essential part in the translational process from experimental to clinical therapies. To optimize clinical translation, robust and representative outcome measures are mandatory. The present manuscript aims to address this need by describing the assessment of three clinically relevant outcome modalities in a pig acute myocardial infarction (AMI) model: infarct size in relation to area at risk (IS/AAR) staining, 3-dimensional transesophageal echocardiography (TEE) and admittance-based pressure-volume (PV) loops. Infarct size is the main determinant driving the transition from AMI to heart failure and can be quantified by IS/AAR staining. Echocardiography is a reliable and robust tool in the assessment of global and regional cardiac function in clinical cardiology. Here, a method for three-dimensional transesophageal echocardiography (3D-TEE) in pigs is provided. Extensive insight into cardiac performance can be obtained by admittance-based pressure-volume (PV) loops, including intrinsic parameters of myocardial function that are pre- and afterload independent. Combined with a clinically feasible experimental study protocol, these outcome measures provide researchers with essential information to determine whether novel therapeutic strategies could yield promising targets for future testing in clinical studies.

Reliable and accurate outcome assessment is the key for translation of preclinical therapies into clinical treatment. The current paper describes how to assess three clinically relevant primary outcome parameters of cardiac performance and damage in a pig acute myocardial infarction model.

急性心肌梗死的猪模型主要成果评估

Mortality after acute myocardial infarction remains substantial and is associated with significant morbidity, like heart failure. Novel therapeutics are ...

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

The value of conventional echocardiography is limited by differences in inter-individual image interpretation and therefore largely dependent on the examiners&#39; expertise. Speckle tracking Echocardiography (STE) is a promising but technically challenging method that can be used to quantitatively assess regional and global systolic and diastolic myocardial performance. Myocardial strain and strain rate can be measured in all three dimensions&#160;&#8212; radial, circumferential, longitudinal &#8212; of myocardial deformation. Standard cross-sectional two-dimensional B-mode images are recorded and subsequently postprocessed by automated continuous frame-by-frame tracking and motion analysis of speckles within the myocardium. Images are recorded as digital loops and synchronized to a 3-lead EKG for timing purposes. Longitudinal deformation is assessed in the apical 4-, 3-, and 2-chamber views. Circumferential and radial deformation are measured in the parasternal short axis plane.
Optimal image quality and accurate tissue tracking are paramount for the correct determination of myocardial performance parameters. Utilizing transthoracic STE in a healthy volunteer, the present article is a detailed outline of the essential steps and potential pitfalls of quantitative echocardiographic myocardial deformation analysis.

Speckle tracking echocardiography is an emerging diagnostic imaging technique for the quantitative assessment of global and regional myocardial performance. Standard view echocardiographic motion images are recorded and deformation parameters are subsequently measured by automated continuous frame-by-frame tracking and motion analysis of speckles within the B-mode images of the myocardium.

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 ...

Histological Quantification of Chronic Myocardial Infarct in Rats

Myocardial infarction is defined as cardiomyocyte death due to prolonged ischemia; an inflammatory response and scar formation (fibrosis) follow the ischemic injury. Following the initial acute phase, chronic remodeling of the left ventricle (LV) modifies the structure and function of the heart. Permanent coronary ligation in small animals has been widely used as a reference model for a chronic model of MI. Thinning of the infarcted wall progressively develops to transmural fibrosis. Histological assessment of infarct size is commonly performed; nevertheless, a standardization of the methods for quantification is missing. Indeed, important methodological aspects, such as the number of sections analyzed and the sampling and quantification methods, are usually not described and therefore preclude comparison across investigations. Too often, quantification is performed on a single section obtained at the level of the papillary muscles. Because novel strategies aimed at reducing infarct expansion and remodeling are under investigation, there is an important need for the standardization of accurate heart sampling protocols. We describe an accurate method to quantify the infarct size using a systematic sampling of harvested rat heart and image analyses of trichromatic stained histological sections obtained from base to apex. We also provide evidence that calculating the expansion index (EI) allowed for infarct size assessment, taking into account changes of the left ventricle throughout the remodeling.

The post-mortem assessment of myocardial infarction (MI) in rodents is based on quantification of the infarct on stained heart sections. We describe an accurate method to quantify the infarct size using systematic sampling of harvested rat hearts from base to apex and image analyses of trichrome-stained histological sections.

大鼠慢性心肌梗塞的组织学定量分析

Myocardial infarction is defined as cardiomyocyte death due to prolonged ischemia; an inflammatory response and scar formation (fibrosis) follow the ...

3D Whole-heart Myocardial Tissue Analysis

Cardiac regenerative therapies aim to protect and repair the injured heart in patients with ischemic heart disease. By injecting stem cells or other biologicals that enhance angio- or vasculogenesis into the infarct border zone (IBZ), tissue perfusion is improved, and the myocardium can be protected from further damage. For maximum therapeutic effect, it is hypothesized that the regenerative substance is best delivered to the IBZ. This requires accurate injections and has led to the development of new injection techniques. To validate these new techniques, we have designed a validation protocol based on myocardial tissue analysis. This protocol includes whole-heart myocardial tissue processing that enables detailed two-dimensional (2D) and three-dimensional (3D) analysis of the cardiac anatomy and intramyocardial injections. In a pig, myocardial infarction was created by a 90-min occlusion of the left anterior descending coronary artery. Four weeks later, a mixture of a hydrogel with superparamagnetic iron oxide particles (SPIOs) and fluorescent beads was injected in the IBZ using a minimally-invasive endocardial approach. 1 h after the injection procedure, the pig was euthanized, and the heart was excised and embedded in agarose (agar). After the solidification of the agar, magnetic resonance imaging (MRI), slicing of the heart, and fluorescence imaging were performed. After image post-processing, 3D analysis was performed to assess the IBZ targeting accuracy. This protocol provides a structured and reproducible method for the assessment of the targeting accuracy of intramyocardial injections into the IBZ. The protocol can be easily used when the processing of scar tissue and/or validation of the injection accuracy of the whole heart is desired.

This protocol describes a novel method for the 3D comparison of whole-heart myocardial tissue with MRI. This is designed for the accurate assessment of intramyocardial injections in the infarct border zone of a chronic porcine model of myocardial infarction.

3D全心脏心肌组织分析

Cardiac regenerative therapies aim to protect and repair the injured heart in patients with ischemic heart disease. By injecting stem cells or other ...

Ultrasonic-augmented Primary Adult Fibroblast Isolation

Primary adult fibroblasts have become an important tool to study fibrosis, fibroblast interactions and inflammation in all body tissues. Since primary fibroblasts cannot divide indefinitely due to myofibroblast differentiation or senescence induction, new cultures must be established regularly. However, there are several obstacles to overcome during the processes of developing a reliable isolation protocol and primary fibroblast isolation itself: the method&#8217;s degree of difficulty (especially for beginners), the risk of bacterial contamination, the required time until primary fibroblasts can be used for experiments, and subsequent cell quality and viability. In this study, a fast, reliable and easy-to-learn protocol to isolate and culture primary adult fibroblasts from mouse heart, lung, liver and kidney combining enzymatic digestion and ultrasonic agitation is provided.

We present a protocol to isolate primary adult fibroblasts in an easy, fast and reliable way, performable by beginners (e.g., students). The procedure combines enzymatic tissue digestion and mechanical agitation with ultrasonic waves to obtain primary fibroblasts. The protocol can easily be adapted to specific experimental requirements (e.g., human tissue).

超声波增强原成人成纤维细胞隔离

Primary adult fibroblasts have become an important tool to study fibrosis, fibroblast interactions and inflammation in all body tissues. Since primary ...