Name: exercise test for evaluation of the functional efficacy of the pig cardiovascular system
Uploaded: 2023-05-12T13:50:00.000+00:00
Duration: 2 min 47 s
Description: Watch this Scientific Journal Video about Exercise Test for Evaluation of the Functional Efficacy of the Pig Cardiovascular System at JoVE.com

作者要感谢国家实验动物中心的Minna Törrönen，Riikka Venäläinen，Heikki Karhunen和Inkeri Niemi在动物工作方面的帮助。这项研究得到了芬兰科学院、ERC和CardioReGenix EU Horizon资助的支持。

所有实验均得到东芬兰大学动物实验委员会的批准。该协议描述了一种临床相关的猪跑步机运动测试，以评估心脏病新疗法的安全性和有效性。本研究使用体重25-80公斤的雌性家猪。这些动物是从商业来源获得的（见 材料表）。
1. 设置跑道
<ol><li>设置跑道，使动物只能向一个方向移动。使用门和舱口防止动物后退。跑道的平面图如图 1 所示，跑道示例如图 2 所示。</li>
	<li>确保跑步机（见 材料表）有足够的空间来改变倾斜度。</li>
	<li>确保跑步机的宽度可调，以防止动物在跑步过程中转动。</li>
	<li>使用透明塑料制作跑步机的前壁。这可以防止动物从跑步机上跑开，但仍然允许动物透过墙壁看到。 注意:动物必须能够透过前墙看到，因为我们的经验表明，如果猪看到墙的另一侧的猪同伴，它们就会更有动力奔跑。</li>
	<li>将心电监护仪和除颤器（见 材料表）放在跑步机旁边。 注意:在压力测试期间可能发生致命的心律失常，特别是如果猪有心肌缺血14,15,16。</li>
	<li>确保跑道包括一个饮水点，动物可以在跑步后喝水和降温。</li>
</ol>2.猪在试验前的适应期
<ol><li>在开始实验之前，将动物安置2周。</li>
	<li>在适应环境的第一周，确保动物习惯他们的处理者和新的住房环境，不包括跑道。</li>
	<li>在适应期的第二周，确保动物习惯跑道。</li>
	<li>开始习惯，让动物熟悉跑道。首先，保持所有大门打开，以便动物可以在赛道上自由行走并探索环境。</li>
	<li>当动物对赛道比较熟悉时，打开跑步机，让动物一次跑一小段时间，比如7分钟。运行时间的长度必须每天延长。 注意:记得在适应期间奖励动物。例如，在本研究中，猪获得了无盐爆米花的奖励。</li>
</ol>3.运动试验
注意:猪应在运动测试前至少 2 小时禁食或在跑步前只喂一小部分食物。
<ol><li>打开跑步机并将坡度设置为5%-10%。</li>
	<li>一旦动物在跑步机上，以 2 公里/小时的启动速度启动跑步机。</li>
	<li>每 60 秒将速度提高 0.5 公里/小时，直到达到 5 公里/小时。总运行时间为15分钟。</li>
	<li>如果动物无法以最大速度全程奔跑，请执行以下步骤。<ol><li>如果猪没有跑到选定的速度，从后面轻轻地推它，因为这可能会给动物一种感觉，它需要跑得更快而不会减速。</li>
		<li>尝试轻轻推动动物最多三次;之后，一次将速度减慢 0.5 公里/小时，直到猪能够处理速度。不要减速到2公里/小时以下。</li>
		<li>如果动物即使以低速也拒绝跑步，请关闭跑步机并停止测试。</li>
	</ol></li>
</ol>4. 运动测试期间的心电图监测
<ol><li>将心电图电极（见 材料表）放置在跑步过程中运动最小的解剖位置，例如肩胛骨或胸部。 注意:使用专为运动测试设计的心电图电极，以获得更好的皮肤粘附。请记住从放置ECG电极的区域剃掉头发。</li>
	<li>记录跑步过程中的心率变化。 注意:我们的经验表明，ST段分析通常由于移动和其他伪影而变得复杂。节律监测也可以使用植入式循环记录器或起搏器来完成。</li>
</ol>5. 数据收集
<ol><li>记录每次更改速度时的运行距离、总时间和速度。 注意:现代跑步机可能会收集许多其他数据，因此必须熟悉跑步机手册以充分发挥设备的潜力。</li>
	<li>注意动物行为的可能变化，例如跛行。 注意:如果需要，请联系兽医并确保动物接受必要的镇痛。将动物从未来的锻炼中移开，直到它完全恢复。</li>
</ol>6. 术后护理
<ol><li>确保动物可以进入供水点。</li>
	<li>例如，用零食或玩具奖励动物。</li>
	<li>跑步后监测动物30分钟是否有可能的不良反应。</li>
</ol>

猪运动耐力评价

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作者声明不存在利益冲突。

这种大型动物运动试验模仿了临床中使用的试验，缩小了临床前研究和临床试验之间终点的差距。它可用于评估严重心血管疾病的新疗法的疗效，例如闭塞性动脉硬化，心力衰竭和缺血性心脏病。本协议中应用的时间点可能因测试的治疗而异。该方案已基于与大型动物合作的长期经验进行标准化，可用于评估心血管基因治疗和其他新型治疗方法的安全性和有效性。
猪的心脏?...

慢性心血管疾病是全世界死亡和发病的重要原因1,2。尽管目前的治疗方法对大多数患者有效，但由于弥漫性慢性疾病或合并症等原因，许多人仍然无法从目前的治疗中受益。此外，在一些患者中，可用的治疗并不能缓解心脏症状，尽管进行了最佳药物治疗，他们的心血管疾病仍会进展3。因此，显然需要为严重的心血管疾病开发新的治疗方案。
在过去的几年中，已经发现了新的分子途径和操纵这些靶点的方法，使基因疗法，细胞疗法和其他新疗法成为治疗严重心血管疾病的现实选择4。然而，在有希望的临床前结果之后，许多心血管应用未能满足临床试验的期望。尽管临床试验疗效不佳，但一些试验已经建立了新疗法的良好安全性5,6,7,8,9。因此，为患者带来新的心血管疗法将需要改进的方法和更好的临床前模型、研究环境和可以预测临床疗效的临床前研究的终点。
在动物模型中，重点通常放在易于量化的终点上，例如从组织学切片计算的毛细血管的数量和面积，或从静息和药理应激下的左心室成像参数。在临床试验中，许多终点更加主观，例如运动耐量或症状缓解4。因此，临床前研究和临床试验中的终点很可能测量应用疗法的不同方面。例如，血管数量的增加并不总是与更好的灌注、心脏功能或运动耐量相关。然而，开发成功的治疗方法需要两种类型的终点10。尽管如此，主要目标始终是缓解症状并改善患者的预后和生活质量。为了实现这一目标，终点测量必须在临床前和临床研究之间更好地匹配4。
心肺健康反映了循环和呼吸系统在持续体力活动期间提供氧气的能力，因此它量化了个体的功能能力。功能能力是关键的预后标志，因为它是心血管和全因死亡风险的强有力的独立预测指标11。心肺健康的改善与死亡风险降低有关12。运动测试适用于评估心血管疾病的有氧表现和治疗反应。根据可用性，在自行车测力计或跑步机上进行测试。通常使用每分钟工作量的逐渐增加，避免突然增加;这导致线性生理反应。运动测试中最重要的变量包括总运动时间、达到的代谢当量 （MET）、心率以及 QRS 波群（Q、R 和 S 波）和 T 波（ST 段）之间心电图 （ECG） 线的变化。临床压力测试成本低，易于获得13.由于这些原因，压力测试，如6分钟步行测试，已被广泛用于临床，也应该用于新疗法的临床前评估。
据我们所知，没有描述良好的大型动物模型来评估基因疗法或其他新疗法的功能疗效。因此，临床相关的运动测试为评估这些新疗法在临床前环境中的效率提供了一个极好的视角。

<table><tbody><tr><td>Defibrillator</td><td>Zoll M series</td><td>TO9K116790</td><td>All portable defribrillators will work</td></tr><tr><td>Defibrillator pads</td><td>Philips</td><td>M3713A</td><td>All pads work, as long as the pads are compatible with the defibrillator</td></tr><tr><td>ECG electrodes</td><td>Several providers</td><td></td><td>Prefer ECG electrodes designed for exercise tests</td></tr><tr><td>Loop recorder</td><td>Abbott Oy</td><td>DM3500</td><td>Optional for rhythm monitoring</td></tr><tr><td>Patient monitor</td><td>Schiller Argus LCM Plus</td><td>7,80,05,935</td><td>All portable ecg monitors will work</td></tr><tr><td>Pigs</td><td>Emolandia Oy</td><td></td><td></td></tr><tr><td>Treadmill</td><td>NordicTrack</td><td></td><td>All treadmills with adjustable incline and speed are suitable for the exercise test.&amp;nbsp; The treadmill should be as long and wide as possible.</td></tr><tr><td>Ultrasound system</td><td>Philips EPIQ 7 ultrasound</td><td></td><td></td></tr><tr><td>Various building materials</td><td>Several providers</td><td></td><td>For building fences, ramps and gates according to the Figure 1 and Figure 2</td></tr><tr><td>Various treats for the animals</td><td></td><td></td><td></td></tr></tbody></table>

exercise test for evaluation of the functional efficacy of the pig cardiovascular system

尽管在治疗方面取得了进展，但心血管疾病仍然是全世界死亡和发病的最大原因之一。基于基因治疗的治疗性血管生成是一种有前途的方法，用于治疗有明显症状的患者，尽管有最佳的药物治疗和侵入性操作。然而，许多有前途的心血管基因治疗技术未能在临床试验中达到预期。一种解释是用于衡量疗效的临床前终点和临床终点不匹配。在动物模型中，重点通常放在易于量化的终点上，例如从组织学切片计算的毛细血管的数量和面积。除了死亡率和发病率外，临床试验的终点是主观的，例如运动耐量和生活质量。然而，临床前和临床终点可能测量应用疗法的不同方面。然而，开发成功的治疗方法需要这两种类型的终点。在诊所，主要目标始终是缓解患者的症状并改善他们的预后和生活质量。为了从临床前研究中获得更好的预测数据，终点测量必须与临床研究中的测量更好地匹配。在这里，我们介绍了临床相关的猪跑步机运动测试方案。本研究旨在:（1）提供可靠的猪运动测试，可用于评估基因疗法和其他新疗法的安全性和功能有效性，以及（2）更好地匹配临床前和临床研究之间的终点。

必须具有与大型动物合作的经验才能成功使用此协议。研究人员需要能够评估动物是否由于疲劳或缺乏动力而停止奔跑。记录速度和距离可能有助于评估这一点，像往常一样，缺乏动力的动物完全停止奔跑，而疲劳的动物在放慢速度后继续奔跑（图3）。如有必要，如果结果似乎不可靠，可以在第二天重复该方案。
腺相关病毒（AAV）处理动物的代表性时?...

Watch this Scientific Journal Video about Exercise Test for Evaluation of the Functional Efficacy of the Pig Cardiovascular System at JoVE.com

作者聚焦:用于评估猪心血管系统功能功效的运动试验  

本协议描述了一种大型动物运动试验模型，用于评估心血管系统在临床前环境中评估新疗法效率的功能能力。它与临床运动测试相当。

猪心血管系统功能功效评价的运动试验

Despite the progress in treatments, cardiovascular diseases are still one of the biggest causes of mortality and morbidity worldwide. Gene therapy-based ...

该研究的目的是为猪提供可靠的运动测试，可用于评估基因疗法和其他新疗法的安全性和功能有效性。通常，心血管动物研究强调易于量化的终点，就像从组织学切片计算毛细血管面积一样。相比之下，临床研究使用更主观的终点，如过度耐受。该方案更好地匹配了临床前和临床研究之间的终点。先前发表的具有较长时间跑步会话的方法旨在评估慢性运动适应，而所提出的方法更适合评估心肺健康。

exercise-test-for-evaluation-functional-efficacy-pig-cardiovascular

Universidad San Sebastian

Research

JoVE Journal

Genetics

Exercise Test for Evaluation of the Functional Efficacy of the Pig Cardiovascular System

1.2K 次观看.  University of Eastern Finland. 该研究的目的是为猪提供可靠的运动测试，可用于评估基因疗法和其他新疗法的安全性和功能有效性。通常，心血管动物研究强调易于量化的终点，就像从组织学切片计算毛细血管面积一样。相比之下，临床研究使用更主观的终点，如过度耐受。该方案更好地匹配了临床前和临床研究之间的终点。先前发表的具有较长时间跑步会话的方法旨在评估慢性运动适应，而所提?...

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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 ...

科研

医学

An Isolated Working Heart System for Large Animal Models

Since its introduction in the late 19th century, the Langendorff isolated heart perfusion apparatus, and the subsequent development of the working heart model, have been invaluable tools for studying cardiovascular function and disease1-15. Although the Langendorff heart preparation can be used for any mammalian heart, most studies involving this apparatus use small animal models (e.g., mouse, rat, and rabbit) due to the increased complexity of systems for larger mammals1,3,11. One major difficulty is ensuring a constant coronary perfusion pressure over a range of different heart sizes &#8211; a key component of any experiment utilizing this device1,11. By replacing the classic hydrostatic afterload column with a centrifugal pump, the Langendorff working heart apparatus described below allows for easy adjustment and tight regulation of perfusion pressures, meaning the same set-up can be used for various species or heart sizes. Furthermore, this configuration can also seamlessly switch between constant pressure or constant flow during reperfusion, depending on the user&#8217;s preferences. The open nature of this setup, despite making temperature regulation more difficult than other designs, allows for easy collection of effluent and ventricular pressure-volume data.

Most studies involving the Langendorff apparatus use small animal models due to the increased complexity of systems for larger mammals. We describe a Langendorff system for large animal models that allows for use across a range of species, including humans, and relatively easy data acquisition.

一个孤立的工作心脏系统的大型动物模型

Since its introduction in the late 19th century, the Langendorff isolated heart perfusion apparatus, and the subsequent development of the working heart ...

Chronic Thromboembolic Pulmonary Hypertension and Assessment of Right Ventricular Function in the Piglet

An original piglet model of Chronic Thromboembolic Pulmonary Hypertension (CTEPH) associated with chronic Right Ventricular (RV) dysfunction is described. Pulmonary Hypertension (PH) was induced in 3-week-old piglets by a progressive obstruction of the pulmonary vascular bed. A ligation of the left Pulmonary Artery (PA) was performed first through a mini-thoracotomy. Second, weekly embolizations of the right lower pulmonary lobe were done under fluoroscopic guidance with n-butyl-2-cyanoacrylate during 5 weeks. Mean Pulmonary Arterial Pressure (mPAP) measured by ritght heart catheterism, increased progressively, as well as Right Atrial pressure and Pulmonary Vascular Resistances (PVR) after 5 weeks compared to sham animals. Right Ventricular (RV) structural and functional remodeling were assessed by transthoracic echocardiography (RV diameters, RV wall thickness, RV systolic function). RV elastance and RV-pulmonary coupling were assessed by Pressure-Volume Loops (PVL) analysis with conductance method. Histologic study of the lung and the right ventricle were also performed. Molecular analyses on RV fresh tissues could be performed through repeated transcutaneous endomyocardial biopsies. Pulmonary microvascular disease in obstructed and unobstructed territories was studied from lung biopsies using molecular analyses and pathology. Furthermore, the reliability and the reproducibility was associated with a range of PH severity in animals. Most aspects of the human CTEPH disease were reproduced in this model, which allows new perspectives for the understanding of the underlying mechanisms (mitochondria, inflammation) and new therapeutic approaches (targeted, cellular or gene therapies) of the overloaded right ventricle but also pulmonary microvascular disease.

Chronic Thromboembolic Pulmonary Hypertension (CTEPH) and Right Ventricular (RV) dysfunction were induced in piglets by progressive obstruction of the pulmonary arteries. Consequences were remarkably similar to those observed in CTEPH patients. This animal model would be a very useful tool for pathophysiology and therapeutic experiments on CTEPH and RV failure.

慢性血栓栓塞性肺动脉高压和右心室功能的仔猪评估

An original piglet model of Chronic Thromboembolic Pulmonary Hypertension (CTEPH) associated with chronic Right Ventricular (RV) dysfunction is described. ...

Surgical Placement of Catheters for Long-term Cardiovascular Exercise Testing in Swine

This protocol describes the surgical procedure to chronically instrument swine and the procedure to exercise swine on a motor-driven treadmill. Early cardiopulmonary dysfunction is difficult to diagnose, particularly in animal models, as cardiopulmonary function is often measured invasively, requiring anesthesia. As many anesthetic agents are cardiodepressive, subtle changes in cardiovascular function may be masked. In contrast, chronic instrumentation allows for measurement of cardiopulmonary function in the awake state, so that measurements can be obtained under quiet resting conditions, without the effects of anesthesia and acute surgical trauma. Furthermore, when animals are properly trained, measurements can also be obtained during graded treadmill exercise.
Flow probes are placed around the aorta or pulmonary artery for measurement of cardiac output and around the left anterior descending coronary artery for measurement of coronary blood flow. Fluid-filled catheters are implanted in the aorta, pulmonary artery, left atrium, left ventricle and right ventricle for pressure measurement and blood sampling. In addition, a 20 G&#160;catheter is positioned in the anterior interventricular vein to allow coronary venous blood sampling.
After a week of recovery, swine are placed on a motor-driven treadmill, the catheters are connected to pressure and flow meters, and swine are subjected to a five-stage progressive exercise protocol, with each stage lasting 3 min. Hemodynamic signals are continuously recorded and blood samples are taken during the last 30 sec of each exercise stage.
The major advantage of studying chronically instrumented animals is that it allows serial assessment of cardiopulmonary function, not only at rest but also during physical stress such as exercise. Moreover, cardiopulmonary function can be assessed repeatedly during disease development and during chronic treatment, thereby increasing statistical power and hence limiting the number of animals required for a study.

Here we present a protocol to assess cardiopulmonary function in awake swine, at rest and during graded treadmill exercise. Chronic instrumentation allows for repeated hemodynamic measurements uninfluenced by cardiodepressive anesthetic agents.

导管手术放置了长期的心血管运动试验猪

This protocol describes the surgical procedure to chronically instrument swine and the procedure to exercise swine on a motor-driven treadmill. Early ...

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 ...

Tachycardia-Induced Cardiomyopathy As a Chronic Heart Failure Model in Swine

A stable and reliable model of chronic heart failure is required for many experiments to understand hemodynamics or to test effects of new treatment methods. Here, we present such a model by tachycardia-induced cardiomyopathy, which can be produced by rapid cardiac pacing in swine.
A single pacing lead is introduced transvenously into fully anaesthetized healthy swine, to the apex of the right ventricle, and fixated. Its other end is then tunneled dorsally to the paravertebral region. There, it is connected to an in-house modified heart pacemaker unit that is then implanted in a subcutaneous pocket. 
After 4 - 8 weeks of rapid ventricular pacing at rates of 200 - 240 beats/min, physical examination revealed signs of severe heart failure - tachypnea, spontaneous sinus tachycardia, and fatigue. Echocardiography and X-ray showed dilation of all heart chambers, effusions, and severe systolic dysfunction. These findings correspond well to decompensated dilated cardiomyopathy and are also preserved after the cessation of pacing.
This model of tachycardia-induced cardiomyopathy can be used for studying the pathophysiology of progressive chronic heart failure, especially hemodynamic changes caused by new treatment modalities like mechanical circulatory supports. This methodology is easy to perform and the results are robust and reproducible.

Here, we present a protocol to produce tachycardia-induced cardiomyopathy in swine. This model represents a potent way to study the hemodynamics of progressive chronic heart failure and the effects of applied treatment.

心动过速诱发的心肌病作为猪慢性心力衰竭模型的研究

A stable and reliable model of chronic heart failure is required for many experiments to understand hemodynamics or to test effects of new treatment ...

Optocardiography and Electrophysiology Studies of Ex Vivo Langendorff-perfused Hearts

Small animal models are most commonly used in cardiovascular research due to the availability of genetically modified species and lower cost compared to larger animals. Yet, larger mammals are better suited for translational research questions related to normal cardiac physiology, pathophysiology, and preclinical testing of therapeutic agents. To overcome the technical barriers associated with employing a larger animal model in cardiac research, we describe an approach to measure physiological parameters in an isolated, Langendorff-perfused piglet heart. This approach combines two powerful experimental tools to evaluate the state of the heart: electrophysiology (EP) study and simultaneous optical mapping of transmembrane voltage and intracellular calcium using parameter sensitive dyes (RH237, Rhod2-AM). The described methodologies are well suited for translational studies investigating the cardiac conduction system, alterations in action potential morphology, calcium handling, excitation-contraction coupling and the incidence of cardiac alternans or arrhythmias.

The objective of this study was to establish a method for investigating cardiac dynamics using a translational animal model. The described experimental approach incorporates dual-emission optocardiography in conjunction with an electrophysiological study to assess electrical activity in an isolated, intact porcine heart model.

前维沃·兰根多夫注入心脏的心电生理学研究

Small animal models are most commonly used in cardiovascular research due to the availability of genetically modified species and lower cost compared to ...

Post-Myocardial Infarction Heart Failure in Closed-chest Coronary Occlusion/Reperfusion Model in G&#246;ttingen Minipigs and Landrace Pigs

The development of heart failure is the most powerful predictor of long-term mortality in patients surviving acute myocardial infarction (MI). There is an unmet clinical need for prevention and therapy of post-myocardial infarction heart failure (post-MI HF). Clinically relevant pig models of post-MI HF are prerequisites for final proof-of-concept studies before entering into clinical trials in drug and medical device development.
Here we aimed to characterize a closed-chest porcine model of post-MI HF in adult G&#246;ttingen minipigs with long-term follow-up including serial cardiac magnetic resonance imaging (CMRI) and to compare it with the commonly used Landrace pig model.
MI was induced by intraluminal balloon occlusion of the left anterior descending coronary artery for 120 min in G&#246;ttingen minipigs and for 90 min in Landrace pigs, followed by reperfusion. CMRI was performed to assess cardiac morphology and function at baseline in both breeds and at 3 and 6 months in G&#246;ttingen minipigs and at 2 months in Landrace pigs, respectively.
Scar sizes were comparable in the two breeds, but MI resulted in a significant decrease of left ventricular ejection fraction (LVEF) only in G&#246;ttingen minipigs, while Landrace pigs did not show a reduction of LVEF. Right ventricular (RV) ejection fraction increased in both breeds despite the negligible RV scar sizes. In contrast to the significant increase of left ventricular end-diastolic (LVED) mass in Landrace pigs at 2 months, G&#246;ttingen minipigs showed a slight increase in LVED mass only at 6 months.
In summary, this is the first characterization of post-MI HF in G&#246;ttingen minipigs in comparison to Landrace pigs, showing that the G&#246;ttingen minipig model reflects post-MI HF parameters comparable to the human pathology. We conclude that the G&#246;ttingen minipig model is superior to the Landrace pig model to study the development of post-MI HF.

The overall goal of the current study is to present the techniques of induction of myocardial infarction (MI) and post-myocardial infarction heart failure (post-MI HF) in closed-chest, adult G&#246;ttingen minipigs and the characterization of post-MI HF model in G&#246;ttingen minipigs as compared to Landrace pigs.

封闭胸冠状动脉闭塞/输液模型中的心肌梗塞后心力衰竭

The development of heart failure is the most powerful predictor of long-term mortality in patients surviving acute myocardial infarction (MI). There is an ...

Measuring Cardiac Output in a Swine Model

Swine are frequently used in medical research given their similar cardiac physiology to that of humans. Measuring cardiac parameters such as stroke volume and cardiac output are essential in this type of research. Contrast ventriculography, thermodilution, and pressure-volume loop (PV-loop) catheters can be used to accurately obtain cardiac performance data depending on which resources and expertise are available. For this study,five Yorkshire swine were anesthetized and intubated. Central venous and arterial access was obtained to place the necessary measurement instruments.A temperature probe was placed in the aortic root. A cold saline bolus was delivered to the right atrium and temperature deflection curve was recorded. Integration of the area under the curve allowed for the calculation of the current cardiac output.A pigtail catheter was percutaneously placed in the left ventricle and 30 mL of iodinated contrast was power injected over 2 seconds. Digital subtraction angiography images were uploaded to volumetric analysis software to calculate the stroke volume and cardiac output. A pressure volume-loop catheter was placed into the left ventricle (LV) and provided continuous pressure and volume data of the LV, which allowed the calculation of both stroke volume and cardiac output.All three methods demonstrated good correlation with each other. The PV-loop catheter and thermodilution exhibited the best correlation with a 3% error and a Pearson coefficient of 0.99, with 95% CI=0.97 to 1.1, (p=0.002). The PV-loop catheter against ventriculography also showed good correlation with a 6% error and a Pearson coefficient of 0.95, 95% CI=0.96 to 1.1 (p=0.01). Finally, thermodilution against ventriculography had a 2% error with r=0.95, 95% CI=0.93 to 1.11, (p=0.01). In conclusion, we state that the PV-loop catheter, contrast ventriculography, and thermodilution each offer certain advantages depending on the researcher's requirements. Each method is reliable and accurate for measuring various cardiac parameters in swine such as the stroke volume and cardiac output.

Thermodilution, pressure-volume loop catheters, and contrast ventriculography are reliable and accurate methods for determining cardiac physiology such as stroke volume and cardiac output in a laboratory setting in swine.

Swine are frequently used in medical research given their similar cardiac physiology to that of humans. Measuring cardiac parameters such as stroke volume ...

Echocardiography Recording in Awake Miniature Pigs

Echocardiography uses ultrasonic waves to non-invasively assess cardiac structure and function and is the standard of care for cardiac assessment and monitoring. The miniature pig, or minipig, is increasingly being used as a model of cardiac disease in medical research. Pigs are notoriously difficult to restrain and handle safely, and, therefore, research echocardiography in this species is almost always performed under anesthesia or heavy sedation. Anesthetics and sedatives universally affect cardiovascular function and may cause the depression of cardiac output and blood pressure, increases or decreases in heart rate and systemic vascular resistance, changes in the electrical rhythm, and altered coronary blood flow. Therefore, sedated or anesthetized echocardiography may not accurately depict the progression of cardiac disease in large animal models, thereby limiting the translational value of these important studies. This paper describes a novel device that allows for standing awake echocardiography in minipigs. In addition, training techniques used to teach pigs to tolerate this painless and non-invasive procedure without the need for hemodynamic-altering anesthetics are described. Standing awake echocardiography represents a safe and feasible way to perform the most common cardiac monitoring test in minipigs for cardiovascular research.

A simple cart construct, built to perform research echocardiography in standing awake minipigs, is described, along with building considerations, training techniques, and representative ultrasound images.

清醒微型猪的超声心动图记录

Echocardiography uses ultrasonic waves to non-invasively assess cardiac structure and function and is the standard of care for cardiac assessment and ...