The authors have nothing to disclose.

该协议遵循华盛顿大学的机构动物护理和使用委员会的指导方针。 1.手术过程和准备成像<ol><li>受试者C57BL / 6小鼠，以TAC或假手术，如前所述10。 </li><li> TAC或假手术后一周，麻醉小鼠中，用2％异氟烷以1L /分钟的 O 2混合感应腔室。通过确认适当反应迟钝麻醉脚趾或尾部捏。使用于眼部兽医药膏，以防止干燥时的麻醉下。通过应用脱毛膏取出胸毛。消毒用70％乙醇的小鼠皮肤。 </li><li>固定鼠标向动物处理平台在仰卧位。维持麻醉的一个稳定的水平，可使用鼻锥提供0.5 - 1％异氟烷以1L /分钟的 O 2混合。 </li><li>应用电极凝胶的小鼠的爪和它们胶带将电极焊盘。 </li><li>插入直肠探头监测体温。通过加热垫或灯保持体温在37℃。 </li><li>应用预热超声凝胶层到鼠标胸部，主要区域覆盖心脏。注意:删除超声凝胶和成像过程干燥后用无菌纱布鼠标。 </li></ol> 2.在主动脉弓查看，使用B模式和多普勒成像评价横向主动脉缩窄<ol><li>使用B模式设置获得以显现主动脉，主要动脉分支，并且缩颈部位主动脉弓图。 <ol><li>倾斜平台上来尽可能的左侧旋转鼠标放到左侧卧位。握住支架上的超声换能器的垂直位置，并将其放置在沿着正确的胸骨旁线胸前，朝向鼠标的下巴指向缺口。注意:不要压缩鼠标胸廓降低TRANSD时ucer;需要的压力最小量。 </li><li>倾斜传感器上在肩胛骨的水平并顺时针旋转略微直到主动脉弓进入图。观察横向主动脉缩窄位点，其位于无名动脉（IA）和左颈总动脉（LCCA）（ 图1）的分支之间。 注:假手术鼠标未检测到收缩。 </li></ol></li><li>点击工作站上的"彩色多普勒"按钮切换到彩色多普勒模式，以监控整个收缩部位的血液流动的方向和速度。获取并点击"电影商店"按钮保存图像。 </li><li>点击"脉冲多普勒"按钮，切换到脉冲波的多普勒模式，地方样本量（虚线光标框）立即远端狭窄网站搜索最高速度狭窄喷射，然后单击"PW多普勒"按钮获得主动脉佛罗里达州的波形流动并测量峰值速度（ 图2）。 </li><li>计算使用改性伯努利方程跨网站收缩压力梯度:压力梯度= 4×2V 以下 2。仅包括与压力梯度范围从40到80毫米汞柱用于进一步分析的小鼠。 </li></ol> 3.在胸骨旁长轴切面，使用B模式和M模式成像来评估心脏尺寸和收缩<ol><li>用鼠标躺在平台上的仰卧位，保持与缺口指向鼠标的头部在垂直的方式换能器。降低对平行于左胸骨旁线胸廓的换能器和逆时针旋转30°。 </li><li>使用B型成像，以获得心脏的一个完整的长轴"矢"的看法。调整换能器的角度和聚焦深度的可视化左心室，脑室间隔墙，以及右心室壁的轻微的部分。小号AVE图像购买心脏壁的厚度和腔室尺寸的测量。用"心套餐"，选择参数，如IVS或LVAW，LVID和LVPW，然后点击图片绘制相应行的每个参数，以获得测量结果。 </li><li>观察心脏室壁运动模式，并检查可能存在的运动异常，包括运动不能，运动功能减退，以及异步。 注意事项:运动不能和运动功能减退表示心脏壁的运动完全和部分损失分别。异步表示不规则，不协调的心脏室壁运动。 </li><li>切换到M模式，地点M型光标垂直于左心室壁在乳头肌水平，并获得用于心脏尺寸和缩短分数（ 图3）的后面测量图像。 </li></ol> 4.在胸骨旁短轴视图中，使用B型和M型成像，以评估心脏形态和功能<ol><li>神父OM胸骨旁长轴切面，通过换能器顺时针旋转90°旋转获得胸骨旁短轴观。调整换能器，得到的横截面"横向"在B模式心脏的图，这两个乳头肌清楚可见，位于右侧（在2和4点的位置）。 </li><li>切换到M型，并将M型轴在左心室的级别中旬。获取和存储图像供以后心脏壁厚，腔尺寸和短轴缩短率（ 图4）测量。用"心套餐"，在SAX（短轴），包括IVS或LVAW，LVID和LVPW，并在图像上单击选择参数绘制相应的线对每个参数，以获得测量结果。 注意:此处获得的测量应在胸骨旁长轴视图（ 图5）获得的那些密切相关。 </li></ol> 5.在心尖四腔心切面，用多普勒显像评估收缩与舒张功能<ol><li>获得心尖四腔视图与在屏幕的底部的心房形象化左，右心室。在B模式中，从短轴视图，向下倾斜平台的左上角角鼠标的头部和定向换能器朝鼠标的右肩。这实质上是实现了心脏抬头朝顶点的"冠"的看法。 </li><li>可视化B模式二尖瓣，并切换到彩色多普勒模式，放置在二尖瓣的末端的样品体积（虚线光标框）。 </li><li>切换到脉冲多普勒模式，以评估跨二尖瓣流动模式。对齐平行于二尖瓣血液流动的方向的多普勒探头光标。使用探针角度小于20°，以确定峰值速度（ 图6）。 </li><li>保存图像供以后的测量。用"心包"，然后选择"MV流"点击各参数，并绘制相应行获得的测量可用测量包括:E峰速度（年初主动心室舒张充盈），峰值速度（与心房收缩晚期充盈），二尖瓣等容舒张和收缩时间（IVRT和IVCT分别），和喷射时间（ET）。 </li><li>通过计算MPI =（IVCT + IVRT）/ ET心肌的性能指数（MPI）。 </li></ol>动物6.后处理程序<ol><li>得到的镇痛和/或无菌盐水腹膜内手术的动物需要时。 </li><li>让动物在俯卧位加热垫恢复。无人看管，直到它已经恢复了足够的意识，以保持胸骨斜卧不要让动物。不返回已经历的过程，以公司的其他动物，直到完全恢复的动物。 </li></ol>

<ol>
	<li>Rockman, H. A., 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=Segregation+of+atrial-specific+and+inducible+expression+of+an+atrial+natriuretic+factor+transgene+in+an+in+vivo+murine+model+of+cardiac+hypertrophy.">Segregation of atrial-specific and inducible expression of an atrial natriuretic factor transgene in an in vivo murine model of cardiac hypertrophy.</a> Proc Natl Acad Sci USA. 88 (18), 8277-8281 (1991).</li><li>Tanaka, N., 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=Transthoracic+echocardiography+in+models+of+cardiac+disease+in+the+mouse.">Transthoracic echocardiography in models of cardiac disease in the mouse.</a> Circulation. 94 (5), 1109-1117 (1996).</li><li>Patten, R. D., Hall-Porter, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Small+animal+models+of+heart+failure:+development+of+novel+therapies,+past+and+present.">Small animal models of heart failure: development of novel therapies, past and present.</a> Circ Heart Fail. 2 (2), 138-144 (2009).</li><li>Heineke, J., Molkentin, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regulation+of+cardiac+hypertrophy+by+intracellular+signalling+pathways.">Regulation of cardiac hypertrophy by intracellular signalling pathways.</a> Nat Rev Mol Cell Biol. 7 (8), 589-600 (2006).</li><li>Oka, T., 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=Cardiac-specific+deletion+of+Gata4+reveals+its+requirement+for+hypertrophy,+compensation,+and+myocyte+viability.">Cardiac-specific deletion of Gata4 reveals its requirement for hypertrophy, compensation, and myocyte viability.</a> Circ Res. 98 (6), 837-845 (2006).</li><li>Gardin, J. M., Siri, F. M., Kitsis, R. N., Edwards, J. G., Leinwand, L. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Echocardiographic+assessment+of+left+ventricular+mass+and+systolic+function+in+mice.">Echocardiographic assessment of left ventricular mass and systolic function in mice.</a> Circ Res. 76 (5), 907-914 (1995).</li><li>Respress, J. L., Wehrens, X. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transthoracic+echocardiography+in+mice.">Transthoracic echocardiography in mice.</a> J Vis Exp. (39), e1738 (2010).</li><li>Pistner, A., Belmonte, S., Coulthard, T., Blaxall, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Murine+echocardiography+and+ultrasound+imaging.">Murine echocardiography and ultrasound imaging.</a> J Vis Exp. (42), e2100 (2010).</li><li>Patten, R. D., Aronovitz, M. J., Bridgman, P., Pandian, N. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Use+of+pulse+wave+and+color+flow+Doppler+echocardiography+in+mouse+models+of+human+disease.">Use of pulse wave and color flow Doppler echocardiography in mouse models of human disease.</a> J Am Soc Echocardiogr. 15 (7), 708-714 (2002).</li><li>deAlmeida, A. C., van Oort, R. J., Wehrens, X. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Transverse+aortic+constriction+in+mice.">Transverse aortic constriction in mice.</a> J Vis Exp. (38), e1729 (2010).</li><li>Pacher, P., Nagayama, T., Mukhopadhyay, P., B&#225;tkai, S., Kass, D. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measurement+of+cardiac+function+using+pressure-volume+conductance+catheter+technique+in+mice+and+rats.">Measurement of cardiac function using pressure-volume conductance catheter technique in mice and rats.</a> Nat Protoc. 3 (9), 1422-1434 (2008).</li><li>Larsen, T. 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=The+isolated+working+mouse+heart:+methodological+considerations.">The isolated working mouse heart: methodological considerations.</a> Pflugers Arch. 437 (6), 979-985 (1999).</li><li>Roth, D. M., Swaney, J. S., Dalton, N. D., Gilpin, E. A., Ross, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Impact+of+anesthesia+on+cardiac+function+during+echocardiography+in+mice.">Impact of anesthesia on cardiac function during echocardiography in mice.</a> Am J Physiol Heart Circ Physiol. 282 (6), H2134-H2140 (2002).</li><li>Pearlman, A. S., Stevenson, J. G., Baker, D. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Doppler+echocardiography:+applications,+limitations+and+future+directions.">Doppler echocardiography: applications, limitations and future directions.</a> Am J Cardiol. 46 (7), 1256-1262 (1980).</li><li>Bauer, 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+speckle-tracking+based+strain+imaging+for+rapid+cardiovascular+phenotyping+in+mice.">Echocardiographic speckle-tracking based strain imaging for rapid cardiovascular phenotyping in mice.</a> Circ Res. 108 (8), 908-916 (2011).</li></ol>

This work was supported in part by NIH/NHLBI grants R00HL0908076 and R01HL116507 (to Q.L.).

超声心动图已被广泛用于评估心脏疾病2,6的啮齿动物模型的心脏功能。相比于侵入或终端的方法，如压力容积环测量11和体外工作心脏12，超声心动图提供了强大的，非侵入性工具来评估在动物活体心脏正在进行结构和功能的改变。获得可靠的数据，通过仔细调节加热装置和麻醉水平保持体温和心脏速率生理范围13内是很重要的。所有图像应该始终根据标准?...

Mouse models of heart disease, such as TAC and myocardial infarction (MI), have been proven to be valuable to study disease mechanisms as well as to develop novel therapeutic strategies3. TAC initially induces compensatory hypertrophy, but prolonged pressure overload leads to cardiac dilatation and heart failure4. The tightness of the aortic constriction directly determines the degree of cardiac hypertrophy and its transition to heart failure. Noninvasive and reliable measurement of pressure gradient across the aortic constriction is essential for the success of these studies. Doppler imaging has been used to assess pressure gradient produced by TAC5, which is a noninvasive alternative for catheter-based pressure measurement.
Echocardiography has been widely used to noninvasively measure cardiac morphology as well as systolic and diastolic function in mice6-8. Two-dimensional B-mode imaging is used to detect abnormal movements or structural changes of the heart. One-dimensional M-mode imaging is used for quantification of cardiac dimensions and contractility. Color and PW Doppler imaging has recently been used on rodent ultrasound, which has broad applications for echocardiography, including measurement of flow directionality and velocity, as well as systolic and diastolic performance9. 
Longitudinal real-time monitoring of cardiac function using echocardiography in B-mode, M-mode, color and PW Doppler mode provides comprehensive assessment of cardiac structure and function in mice under physiological and pathological conditions. Here we provide a detailed description of the use of echocardiographic imaging to monitor dynamic cardiac morphological and functional changes in mice following TAC or sham surgery.

<table><tbody><tr><td>Anesthesia equipment</td><td>Harvard Apparatus, 84 October Hill Road&lt;br/&gt; Holliston, MA</td><td>723015</td><td></td></tr><tr><td>Vevo 2100 Imaging System</td><td>VisualSonics Inc., 3080 Yonge Street Suite 6100, Box 66, Toronto, Ontario, Canada</td><td>Vevo 2100</td><td></td></tr><tr><td>Aquasonic ultrasound gel</td><td>Parker Laboratories, 286 Eldridge Rd, Fairfield, NJ&amp;nbsp;</td><td>03-50</td><td></td></tr><tr><td>Isoflurane</td><td>Piramal Healthcare, Inc, 3950 Schelden Circle&lt;br/&gt; Bethlehem, PA&amp;nbsp;</td><td>NDC 66794-017-25</td><td></td></tr><tr><td>F/air anesthesia gas filter unit</td><td>A.M. Bickford, Inc, 12318 Big Tree Rd, Wales Center, NY&amp;nbsp;</td><td>80120</td><td></td></tr></tbody></table>

assessment of cardiac morphological and functional changes in mouse model of transverse aortic constriction by echocardiographic imaging

Transverse aortic constriction (TAC) in mice has been used as a valuable model to study mechanisms of cardiac hypertrophy and heart failure1. A reliable noninvasive method is essential to assess real-time cardiac morphological and functional changes in animal models of heart disease. Transthoracic echocardiography represents an important tool for noninvasive assessment of cardiac structure and function2. Here we used a high-resolution ultrasound imaging system to monitor myocardial remodeling and heart failure progression over time in a mouse model of TAC. B-mode, M-mode, and Doppler imaging were used to precisely assess cardiac hypertrophy, ventricular dilatation, and functional deterioration in mice following TAC. Color and pulse wave (PW) Doppler imaging was used to noninvasively measure pressure gradient across the aortic constriction created by TAC and to assess transmitral blood flow in mice. Thus transthoracic echocardiographic imaging provides comprehensive noninvasive measurements of cardiac dimensions and function in mouse models of heart disease.

图1示出了进行假（ 图1A）的小鼠心脏或TAC手术（ 图1B）的主动脉弓视图的B模式图像。主动脉弓，无名动脉，左颈总动脉和左锁骨下动脉被示出。需要注意的是主动脉缩窄是TAC清晰可见，但不假心脏。从主动脉视图彩色多普勒图像示于图2A。穿过缩颈部位的主动脉流的波形是由脉冲多普勒成像（ 图2B）捕获。?...

Watch this Scientific Journal Video about Assessment of Cardiac Morphological and Functional Changes in Mouse Model of Transverse Aortic Constriction by Echocardiographic Imaging at JoVE.com

Assessment of Cardiac Morphological and Functional Changes in Mouse Model of Transverse Aortic Constriction by Echocardiographic Imaging

此协议的目的是通过横向主动脉缩窄创建心脏疾病的小鼠模型评估无创心脏结构和功能改变，采用B和M型超声心动图和彩色/脉冲多普勒成像。

在横向主动脉缩窄的小鼠模型和心脏形态学评估功能改变通过超声心动图成像

Transverse aortic constriction (TAC) in mice has been used as a valuable model to study mechanisms of cardiac hypertrophy and heart failure1. A reliable ...

assessment-cardiac-morphological-functional-changes-mouse-model

Research

JoVE Journal

Medicine

18.1K 次观看.  University of Washington. 此协议的目的是通过横向主动脉缩窄创建心脏疾病的小鼠模型评估无创心脏结构和功能改变，采用B和M型超声心动图和彩色/脉冲多普勒成像。 

视频: Assessment of Cardiac Morphological and Functional Changes in Mouse Model of Transverse Aortic Constriction by Echocardiographic Imaging

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

Murine Echocardiography and Ultrasound Imaging

Rodent models of cardiac pathophysiology represent a valuable research tool to investigate mechanism of disease as well as test new therapeutics.1 Echocardiography provides a powerful, non-invasive tool to serially assess cardiac morphometry and function in a living animal.2 However, using this technique on mice poses unique challenges owing to the small size and rapid heart rate of these animals.3 Until recently, few ultrasound systems were capable of performing quality echocardiography on mice, and those generally lacked the image resolution and frame rate necessary to obtain truly quantitative measurements. Newly released systems such as the VisualSonics Vevo2100 provide new tools for researchers to carefully and non-invasively investigate cardiac function in mice. This system generates high resolution images and provides analysis capabilities similar to those used with human patients. Although color Doppler has been available for over 30 years in humans, this valuable technology has only recently been possible in rodent ultrasound.4,5 Color Doppler has broad applications for echocardiography, including the ability to quickly assess flow directionality in vessels and through valves, and to rapidly identify valve regurgitation. Strain analysis is a critical advance that is utilized to quantitatively measure regional myocardial function.6 This technique has the potential to detect changes in pathology, or resolution of pathology, earlier than conventional techniques. Coupled with the addition of three-dimensional image reconstruction, volumetric assessment of whole-organs is possible, including visualization and assessment of cardiac and vascular structures. Murine-compatible contrast imaging can also allow for volumetric measurements and tissue perfusion assessment.

This video demonstrates use of a rail-mounted high-frequency ultrasound probe to perform echocardiography on an anesthetized mouse. The methods describe both conventional two-dimensional and M-mode measurements of cardiac function in addition to newer, more powerful tools such as color Doppler, strain analysis, as well as general and targeted contrast imaging.

小鼠超声心动图和超声成像

Rodent models of cardiac pathophysiology represent a valuable research tool to investigate mechanism of disease as well as test new therapeutics.1  ...

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, ...

Transverse Aortic Constriction in Mice

Transverse aortic constriction (TAC) in the mouse is a commonly used experimental model for pressure overload-induced cardiac hypertrophy and heart failure.1 TAC initially leads to compensated hypertrophy of the heart, which often is associated with a temporary enhancement of cardiac contractility. Over time, however, the response to the chronic hemodynamic overload becomes maladaptive, resulting in cardiac dilatation and heart failure.2 The murine TAC model was first validated by Rockman et al.1, and has since been extensively used as a valuable tool to mimic human cardiovascular diseases and elucidate fundamental signaling processes involved in the cardiac hypertrophic response and heart failure development. When compared to other experimental models of heart failure, such as complete occlusion of the left anterior descending (LAD) coronary artery, TAC provides a more reproducible model of cardiac hypertrophy and a more gradual time course in the development of heart failure. Here, we describe a step-by-step procedure to perform surgical TAC in mice. To determine the level of pressure overload produced by the aortic ligation, a high frequency Doppler probe is used to measure the ratio between blood flow velocities in the right and left carotid arteries.3, 4 With surgical survival rates of 80-90%, transverse aortic banding is an effective technique of inducing left ventricular hypertrophy and heart failure in mice.

Transverse aortic constriction (TAC) in the mouse is a commonly used experimental model to study mechanisms underlying cardiac hypertrophy and heart failure development. Here, we describe procedures to constrict the aorta to create a reproducible degree of cardiac hypertrophy in mice.

在小鼠体内的横向主动脉缩窄

Transverse aortic constriction (TAC) in the mouse is a commonly used experimental model for pressure overload-induced cardiac hypertrophy and heart ...

生物学

Echocardiographic Approaches and Protocols for Comprehensive Phenotypic Characterization of Valvular Heart Disease in Mice

The aim of this manuscript and accompanying video is to provide an overview of the methods and approaches used for imaging heart valve function in rodents, with detailed descriptions of the appropriate methods for anesthesia, the echocardiographic windows used, the imaging planes and probe orientations for image acquisition, the methods for data analysis, and the limitations of emerging technologies for the evaluation of cardiac and valvular function. Importantly, we also highlight several future areas of research in cardiac and heart valve imaging that may be leveraged to gain insights into the pathogenesis of valve disease in preclinical animal models. We propose that using a systematic approach to evaluating cardiac and heart valve function in mice can result in more robust and reproducible data, as well as facilitate the discovery of previously underappreciated phenotypes in genetically-altered and/or physiologically-stressed mice.

This protocol provides a detailed description of the echocardiographic approach for comprehensive phenotyping of heart and heart valve function in mice.

超声心动图方法和协议心脏瓣膜疾病的综合表型特征小鼠

The aim of this manuscript and accompanying video is to provide an overview of the methods and approaches used for imaging heart valve function in ...

Minimally Invasive Transverse Aortic Constriction in Mice

Minimally invasive transverse aortic constriction (MTAC) is a more desirable method for the constriction of the transverse aorta in mice than standard open-chest transverse aortic constriction (TAC). Although transverse aortic constriction is a highly functional method for the induction of high pressure in the left ventricle, it is a more difficult and lengthy procedure due to its use of artificial ventilation with tracheal intubation. TAC is oftentimes also less survivable, as the newer method, MTAC, neither requires the cutting of the ribs and intercostal muscles nor tracheal intubation with a ventilation setup. In MTAC, as opposed to a thoracotomy to access to the chest cavity, the aortic arch is reached through a midline incision in the anterior neck. The thyroid is pulled back to reveal the sternal notch. The sternum is subsequently cut down to the second rib level, and the aortic arch is reached simply by separating the connective tissues and thymus. From there, a suture can be wrapped around the arch and tied with a spacer, and then the sternal cut and skin can be closed. MTAC is a much faster and less invasive way to induce left ventricular hypertension and enables the possibility for high-throughput studies. The success of the constriction can be verified using high-frequency trans-thoracic echocardiography, particularly color Doppler and pulsed-wave Doppler, to determine the flow velocities of the aortic arch and left and right carotid arteries, the dimension of the blood vessels, and the left ventricular function and morphology. A successful constriction will also trigger significant histopathological changes, such as cardiac muscle cell hypertrophy with interstitial and perivascular fibrosis. Here, the procedure of MTAC is described, demonstrating how the resulting flow changes in the carotid arteries can be examined with echocardiography, gross morphology, and histopathological changes in the heart.

Minimally invasive transverse aortic constriction (MTAC) conserves the essentials of regular transverse aortic constriction (TAC) while eliminating the use of a ventilator with tracheal intubation. It proves to be a highly desirable method for high-throughput studies on left ventricular overload, particularly in translational studies.

微创横向主动脉缩窄小鼠

Minimally invasive transverse aortic constriction (MTAC) is a more desirable method for the constriction of the transverse aorta in mice than standard ...

Echocardiographic and Histological Examination of Cardiac Morphology in the Mouse

An increasing number of genetically modified mouse models has become available in recent years. Moreover, the number of pharmacological studies performed in mice is high. Phenotypic characterization of these mouse models also requires the examination of cardiac function and morphology. Echocardiography and magnetic resonance imaging (MRI) are commonly used approaches to characterize cardiac function and morphology in mice. Echocardiographic and MRI equipment specialized for use in small rodents is&#160;expensive and requires a dedicated space. This protocol describes cardiac measurements in mice using a clinical echocardiographic system with a 15 MHz human vascular probe. Measurements are performed on anesthetized adult mice. At least three image sequences are recorded and analyzed for each animal in M-mode in the parasternal short-axis view. Afterwards, cardiac histological examination is performed, and cardiomyocyte diameters are determined on hematoxylin-eosin- or wheat germ agglutinin (WGA)-stained paraffin sections. Vessel density is determined morphometrically after Pecam-1 immunostaining. The protocol has been applied successfully to pharmacological studies and different genetic animal models under baseline conditions, as well as after experimental myocardial infarction by the permanent ligation of the left anterior descending coronary artery (LAD). In our experience, echocardiographic investigation is limited to anesthetized animals and is feasible in adult mice weighing at least 25 g.

Echocardiographic examination is frequently used in mice. Expensive high-resolution ultrasound devices have been developed for this purpose. This protocol describes an affordable echocardiographic procedure combined with histological morphometric analyses to determine cardiac morphology.

超声心动图与小鼠心脏形态学的组织学检查

An increasing number of genetically modified mouse models has become available in recent years. Moreover, the number of pharmacological studies performed ...

Revealing Subtle Changes in Cardiac Function using Transthoracic Dobutamine Stress Echocardiography in Mice

Left ventricular (LV) dysfunction paves the final pathway for a multitude of cardiac disorders. With the non-invasive high-frequency transthoracic dobutamine stress echocardiography in humans, a reductionist investigation approach to unmask subtle changes in cardiac function has become possible. Here, we provide a protocol for using this technique in mice to facilitate expanded analysis of LV architecture and function in physiology and pathology enabling the observation of alterations in models of cardiac disease hidden in unstressed hearts. This investigation can be performed in one and the same animal and allows both, basal and pharmacologically stress-induced measurements. We outline detailed criteria for appropriate anesthesia, imaging-based LV analysis, consideration of intra- and interobserver variability, and obtaining positive inotrope response that can be attained in mice after intraperitoneal injection of dobutamine under near physiological conditions. To recapitulate the characteristics of human physiology and disease in small animal models, we highlight critical pitfalls in evaluation, e.g., a pronounced Bowditch effect in mice. To further meet translational objectives, we compare stress-induced effects in humans and mice. When used in translational studies, attention must be paid to physiological differences between mice and human. Experimental rigor dictates that some parameters assessed in patients can only be used with caution due to restrictions in spatial and temporal resolution in mouse models.

Left ventricular dysfunction constitutes the final common pathway for a host of cardiac disorders. We here provide a detailed protocol of transthoracic dobutamine stress echocardiography approach for comprehensive evaluation of the left ventricular function of mouse models of cardiac disease as well as cardiac phenotyping.

Left ventricular (LV) dysfunction paves the final pathway for a multitude of cardiac disorders. With the non-invasive high-frequency transthoracic ...

A Modified Technique for Transverse Aortic Constriction in Mice

Transverse aortic constriction (TAC) is a frequently used surgery in research regarding heart failure and cardiac hypertrophy based on the formation of pressure overload in mouse models. The main challenge of this procedure is to clearly visualize the transverse aortic arch and precisely band the target vessel. Classical approaches perform a partial thoracotomy to expose the transverse aortic arch. However, it is an open-chest model that causes a rather large surgical trauma and requires a ventilator during the surgery. To prevent unnecessary trauma and simplify the operating procedure, the aortic arch is approached via the proximal proportion of the sternum, reaching and binding the target vessel using a small self-made retractor that contains a snare. This procedure can be conducted without entering the pleura cavity and does not need a ventilator or microsurgical operation, which leaves the mice with physiological breathing patterns, simplifies the procedure, and significantly reduces operation time. Due to the less invasive approach and less operation time, mice can undergo fewer stress reactions and recover rapidly.

The present protocol describes a modified and simplified technique with a minimally invasive transverse aortic constriction (TAC) procedure using a self-made retractor. This procedure can be conducted without a ventilator or microscope and introduces pressure overload, eventually leading to cardiac hypertrophy or heart failure.

一种改良的小鼠横主动脉收缩技术

Transverse aortic constriction (TAC) is a frequently used surgery in research regarding heart failure and cardiac hypertrophy based on the formation of ...