Name: morphological and functional assessment of the right ventricle using 3d echocardiography
Uploaded: 2020-10-28T13:00:00
Description: Watch this Scientific Journal Video about Morphological and Functional Assessment of the Right Ventricle Using 3D Echocardiography at JoVE.com

Project no. NVKP_16-1&#8211;2016-0017 (&#8217;National Heart Program&#8217;) has been implemented with the support provided from the National Research, Development and Innovation Fund of Hungary, financed under the NVKP_16 funding scheme. The research was financed by the Thematic Excellence Programme (2020-4.1.1.-TKP2020) of the Ministry for Innovation and Technology in Hungary, within the framework of the Therapeutic Development and Bioimaging thematic programmes of the Semmelweis University.

The protocol follows the guidelines of the institution&#39;s human research ethics committee and the patients of the clinical cases gave their written informed consent to the study.
1. Technical requirements
<ol>
	<li>For 3D acquisition and analysis, use appropriate software and hardware. Use ECG cables of the echocardiography device; moreover, it is mandatory for the complete 3D acquisition protocol described below.</li>
	<li>For 3D acquisition, use a 3D echocardiographic probe and 3D-compa...

<ol>
	<li>Edler, I., Lindstrom, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+history+of+echocardiography.">The history of echocardiography.</a> Ultrasound in Medicine and Biology. 30 (12), 1565-1644 (2004).</li><li>Ho, S. Y., Nihoyannopoulos, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Anatomy,+echocardiography,+and+normal+right+ventricular+dimensions.">Anatomy, echocardiography, and normal right ventricular dimensions.</a> Heart. 92 (Suppl 1), i2-i13 (2006).</li><li>Genovese, D., 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=Comparison+Between+Four-Chamber+and+Right+Ventricular-Focused+Views+for+the+Quantitative+Evaluation+of+Right+Ventricular+Size+and+Function.">Comparison Between Four-Chamber and Right Ventricular-Focused Views for the Quantitative Evaluation of Right Ventricular Size and Function.</a> Journal of the American Society of Echocardiography. 32 (4), 484-494 (2019).</li><li>Kovacs, A., Lakatos, B., Tokodi, M., Merkely, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Right+ventricular+mechanical+pattern+in+health+and+disease:+beyond+longitudinal+shortening.">Right ventricular mechanical pattern in health and disease: beyond longitudinal shortening.</a> Heart Failure Reviews. 24 (4), 511-520 (2019).</li><li>Antoni, M. L., 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=Prognostic+value+of+right+ventricular+function+in+patients+after+acute+myocardial+infarction+treated+with+primary+percutaneous+coronary+intervention.">Prognostic value of right ventricular function in patients after acute myocardial infarction treated with primary percutaneous coronary intervention.</a> Circulation: Cardiovascular Imaging. 3 (3), 264-271 (2010).</li><li>Amsallem, 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=Right+Heart+End-Systolic+Remodeling+Index+Strongly+Predicts+Outcomes+in+Pulmonary+Arterial+Hypertension:+Comparison+With+Validated+Models.">Right Heart End-Systolic Remodeling Index Strongly Predicts Outcomes in Pulmonary Arterial Hypertension: Comparison With Validated Models.</a> Circulation: Cardiovascular Imaging. 10 (6), (2017).</li><li>Merlo, 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=The+Prognostic+Impact+of+the+Evolution+of+RV+Function+in+Idiopathic+DCM.">The Prognostic Impact of the Evolution of RV Function in Idiopathic DCM.</a> JACC: Cardiovascular Imaging. 9 (9), 1034-1042 (2016).</li><li>Addetia, K., Muraru, D., Badano, L. P., Lang, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=New+Directions+in+Right+Ventricular+Assessment+Using+3-Dimensional+Echocardiography.">New Directions in Right Ventricular Assessment Using 3-Dimensional Echocardiography.</a> JAMA Cardiology. , (2019).</li><li>Nagata, Y., 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=Prognostic+Value+of+Right+Ventricular+Ejection+Fraction+Assessed+by+Transthoracic+3D+Echocardiography.">Prognostic Value of Right Ventricular Ejection Fraction Assessed by Transthoracic 3D Echocardiography.</a> Circulation: Cardiovascular Imaging. 10 (2), (2017).</li><li>Surkova, 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=Relative+Prognostic+Importance+of+Left+and+Right+Ventricular+Ejection+Fraction+in+Patients+With+Cardiac+Diseases.">Relative Prognostic Importance of Left and Right Ventricular Ejection Fraction in Patients With Cardiac Diseases.</a> Journal of the American Society of Echocardiography. 32 (11), 1407-1415 (2019).</li><li>Maffessanti, F., 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=Age-,+body+size-,+and+sex-specific+reference+values+for+right+ventricular+volumes+and+ejection+fraction+by+three-dimensional+echocardiography:+a+multicenter+echocardiographic+study+in+507+healthy+volunteers.">Age-, body size-, and sex-specific reference values for right ventricular volumes and ejection fraction by three-dimensional echocardiography: a multicenter echocardiographic study in 507 healthy volunteers.</a> Circulation: Cardiovascular Imaging. 6 (5), 700-710 (2013).</li><li>. GE 4D RVQ White Paper Available from: <a target="_blank" href="https://www.imv-imaging.com/media/5879/4d_auto_rvq_whitepaper_v8.pdf">https://www.imv-imaging.com/media/5879/4d_auto_rvq_whitepaper_v8.pdf</a> (2017)</li><li>Medvedofsky, D., 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=Novel+Approach+to+Three-Dimensional+Echocardiographic+Quantification+of+Right+Ventricular+Volumes+and+Function+from+Focused+Views.">Novel Approach to Three-Dimensional Echocardiographic Quantification of Right Ventricular Volumes and Function from Focused Views.</a> Journal of the American Society of Echocardiography. 28 (10), 1222-1231 (2015).</li><li>Lakatos, B., 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=Quantification+of+the+relative+contribution+of+the+different+right+ventricular+wall+motion+components+to+right+ventricular+ejection+fraction:+the+ReVISION+method.">Quantification of the relative contribution of the different right ventricular wall motion components to right ventricular ejection fraction: the ReVISION method.</a> Cardiovascular Ultrasound. 15 (1), 8 (2017).</li><li>Lakatos, B. 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=Dominance+of+free+wall+radial+motion+in+global+right+ventricular+function+of+heart+transplant+recipients.">Dominance of free wall radial motion in global right ventricular function of heart transplant recipients.</a> Clinical Transplantation. 32 (3), e13192 (2018).</li><li>Raina, A., Vaidya, A., Gertz, Z. M., Susan, C., Forfia, P. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Marked+changes+in+right+ventricular+contractile+pattern+after+cardiothoracic+surgery:+implications+for+post-surgical+assessment+of+right+ventricular+function.">Marked changes in right ventricular contractile pattern after cardiothoracic surgery: implications for post-surgical assessment of right ventricular function.</a> Journal of Heart and Lung Transplantation. 32 (8), 777-783 (2013).</li><li>Nowak-Machen, 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=Regional+Right+Ventricular+Volume+and+Function+Analysis+Using+Intraoperative+3-Dimensional+Echocardiography-Derived+Mesh+Models.">Regional Right Ventricular Volume and Function Analysis Using Intraoperative 3-Dimensional Echocardiography-Derived Mesh Models.</a> Journal of Cardiothoracic and Vascular Anesthesia. 33 (6), 1527-1532 (2019).</li><li>Pettersen, 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=Contraction+pattern+of+the+systemic+right+ventricle+shift+from+longitudinal+to+circumferential+shortening+and+absent+global+ventricular+torsion.">Contraction pattern of the systemic right ventricle shift from longitudinal to circumferential shortening and absent global ventricular torsion.</a> Journal of the American College of Cardiology. 49 (25), 2450-2456 (2007).</li><li>Moceri, P., 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=Three-dimensional+right-ventricular+regional+deformation+and+survival+in+pulmonary+hypertension.">Three-dimensional right-ventricular regional deformation and survival in pulmonary hypertension.</a> European Heart Journal - Cardiovascular Imaging. , (2017).</li><li>Addetia, 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=Three-dimensional+echocardiography-based+analysis+of+right+ventricular+shape+in+pulmonary+arterial+hypertension.">Three-dimensional echocardiography-based analysis of right ventricular shape in pulmonary arterial hypertension.</a> European Heart Journal - Cardiovascular Imaging. 17 (5), 564-575 (2016).</li><li>Addetia, 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=Morphologic+Analysis+of+the+Normal+Right+Ventricle+Using+Three-Dimensional+Echocardiography-Derived+Curvature+Indices.">Morphologic Analysis of the Normal Right Ventricle Using Three-Dimensional Echocardiography-Derived Curvature Indices.</a> Journal of the American Society of Echocardiography. 31 (5), 614-623 (2018).</li><li>Lakatos, B. 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=Exercise-induced+shift+in+right+ventricular+contraction+pattern:+novel+marker+of+athlete's+heart?.">Exercise-induced shift in right ventricular contraction pattern: novel marker of athlete's heart?.</a> American Journal of Physiology - Heart and Circulatory. , (2018).</li><li>Corrado, D., 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=Arrhythmogenic+right+ventricular+cardiomyopathy:+evaluation+of+the+current+diagnostic+criteria+and+differential+diagnosis.">Arrhythmogenic right ventricular cardiomyopathy: evaluation of the current diagnostic criteria and differential diagnosis.</a> European Heart Journal. , (2019).</li><li>Luo, 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=Right+ventricular+outflow+tract+systolic+function+correlates+with+exercise+capacity+in+patients+with+severe+right+ventricle+dilatation+after+repair+of+tetralogy+of+Fallot.">Right ventricular outflow tract systolic function correlates with exercise capacity in patients with severe right ventricle dilatation after repair of tetralogy of Fallot.</a> Interactive Cardiovascular and Thoracic Surgery. 24 (5), 755-761 (2017).</li></ol>

3D analysis of the RV represents an important step in everyday cardiology practice. In parallel with the growing interest of the morphology and function of the previously neglected cardiac chamber, these novel solutions provide clinically meaningful information about the right side of the heart. While 3D acquisition has several aspects that markedly differ from 2D echocardiographic imaging, by keeping special attention to the critical points and by using a thorough protocol, 3D RV analysis may progress from a scientific ...

Echocardiography came a long way from its first clinical applications in the 1950s1. The first one-dimensional ultrasound probes were designed to provide simple linear diameters of the chamber walls and lumens; however, they undoubtedly represent a milestone in cardiovascular imaging. The development of two-dimensional (2D) ultrasound imaging was another major step by providing much more precise quantification of morphology and function and is still considered to be the standard method in everyday clinical practice. Nevertheless, 2D echocardiography-based assessment still carries a major limitation of the technique: imaging of a given chamber from a few tomographic planes does not adequately characterize the morphology and function of a three-dimensional (3D) structure. This problem is even more pronounced in the case of the right ventricle (RV): compared to the relatively simple bullet-shaped left ventricle (LV), the RV has a complex geometry2 that cannot be adequately quantified using linear diameters or areas3. Despite these widely known facts, RV morphology and function are usually measured by such simple parameters in the clinical practice.
For many decades, the RV was considered to have a much less important role in circulation compared to its left counterpart. Several landmark papers defeated this standpoint showing the strong prognostic role of RV geometry and function in a wide variety of diseases4,5,6,7. Numerous studies demonstrated the incremental value of RV measurement even by using relatively simple conventional parameters, which highlights the importance and need for more precise quantification of the chamber with potentially meaningful clinical value.
3D echocardiography overcomes several limitations of the 2D assessment of the cardiac chambers. While the measurement of volumes and also functional parameters free of geometrical assumptions may be of high interest in the case of the LV as well, it may gain particular importance in the assessment of the RV8. 3D-derived RV volumes and ejection fraction (EF) are shown to have significant prognostic value in various cardiovascular conditions9,10.
Nowadays, several vendors provide semi-automated solutions for 3D RV assessment with validated results against gold standard cardiac magnetic resonance (MR) measurements11,12. The technical requirements of 3D assessment are essential parts of a state-of-the-art cardiovascular imaging department nowadays, and it is expected that it will soon be part of the general equipment in every echocardiography lab. With proper expertise in 3D acquisition and post-processing, 3D RV analysis can be easily implemented into the standard examination protocol.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>3V-D/4V-D/4Vc-D</td>
			<td>General Electric</td>
			<td>n.a.</td>
			<td>ultrasound probe</td>
		</tr>
		<tr>
			<td>4D Auto RVQ</td>
			<td>General Electric</td>
			<td>n.a.</td>
			<td>software for analysis</td>
		</tr>
		<tr>
			<td>E9/E95</td>
			<td>General Electric</td>
			<td>n.a.</td>
			<td>ultrasound machine</td>
		</tr>
		<tr>
			<td>EchoPac v203</td>
			<td>General Electric</td>
			<td>n.a.</td>
			<td>software for analysis</td>
		</tr>
	</tbody>
</table>

morphological and functional assessment of the right ventricle using 3d echocardiography

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

3D analysis of the RV is feasible in a wide variety of cardiovascular diseases. Case 1 is a healthy volunteer with normal ventricular volumes and function (Figure 1). Case 2 is a post-mitral valve repair patient who is a typical example for the conflicting results of conventional 2D assessment: while TAPSE is markedly reduced, the patient does not show any signs of RV dysfunction and a maintained RV global systolic function was confirmed by normal 3D RV EF (<...

Watch this Scientific Journal Video about Morphological and Functional Assessment of the Right Ventricle Using 3D Echocardiography at JoVE.com

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

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

Traditionally, it was believed that the right side of the heart has a minor role in circulation; however, more and more data suggest that right ...

Numerous clinical studies highlighted the diagnostic and prognostic role of right ventricle morphology and function, showing the need for detailed quantification of structure and function of the chamber. Compared to its left counterpart, the right ventricle has a much more complex anatomy and motion pattern. Therefore, only 3D acquisitions provide the opportunity of adequate volumetric measurements.3D echocardiographic assessment of the right ventricle is a precise, fast and highly reproducible technique with an established added clinical value in a wide variety of diseases. Beyond right ventricular measurements, 3D acquisitions give the opportunity of three-dimensional left ventricular or even heart in the same setting. Compared to the traditional echocardiographic examination, three-dimensional measurements require a slightly different approach.Nevertheless, the currently available semi-automatic methods facilitate an easy implementation through everyday clinical practice For the acquisition of 3D images, confirm the correct right ventricle focused view from the 2D echocardiography images. If the free wall of the right ventricle is poorly visualized in this view, the expected 3D image quality will not be optimal for further analysis. If the image is acceptable, use the 4D button to switch to live 3D imaging and use the 12-slice mode for the 3D view to acquire a triplane image of the region of interest, as well as nine cross-sectional planes that can be freely modified.By rotation and correct positioning of the cut planes, confirm the visibility of the entire right ventricle free wall, including the outflow tract and apical segments, and use the left tilting of the sector to further adjust the image. Using the single-beat mode, select an optimal image depth, width, and frame rate and obtain 3D loops of the right ventricle. Using the multi-beat mode, reconstruct the acquired 3D loop from a given number of heart cycles.When the acquired 3D volume has been stitched together, position the probe at the region of interest and ask the patient to take and hold a deep breath. The expanding lungs will typically cover the entire image. Ask the patient to exhale slowly.As the lungs deflate, the right ventricle should become visible again. When the entire right ventricle free wall and septum reappear, ask the patient to hold their breath in this state. Select multi-beat and begin the acquisition.The 3D loops will build up during the select number of heart cycles. When the entire right ventricle can be visualized, instruct the patient to breathe freely again. Then check the obtained loop to confirm that there are no stitching or dropout artifacts.For 4D right ventricle analysis, open the right ventricle-focused 3D loop from the patient library in the appropriate 4D analysis software program and orient the right ventricle on four predefined cut planes. Place two markers to the center of the tricuspid valve in the upper and lower left long axis planes and use the rotation tool to adjust the long axis of the image to the actual long axis of the right ventricle. Reference images on the upper right edges show how the correct orientation should appear.In the upper and lower right panels, use rotation to align the short axis images into the correct position using the reference images as a guide. Click set landmarks to set landmarks in two images, and mark the tricuspid annulus at the tricuspid valve free wall and septum and the right ventricle apex on the previously oriented apical four-chamber view. On the right side, set the right ventricle posterior and anterior insertion points and the right ventricle free wall using the reference images as a guide.When all of the landmarks have been set, the software will automatically jump to the review window. Review and manually correct the automatic endocardial border detection throughout the entire cardiac cycle as necessary. In the case of false tracking, click the endocardial borders to correct them as necessary.Using the rotation tool on the short axis, track along the entire circumference of the right ventricle to review the images. Select pen size to adjust the magnitude of correction. When the tracking is correct, click results and review the final 3D volumetric data and other calculated parameters in the worksheet panel.If further adjustments are needed, click on the appropriate parameter to make a modification. If the tracking and the 3D parameters appear to be valid, click approve and exit to save the values. Three dimensional analysis of the right ventricle is feasible in a wide variety of cardiovascular diseases.For example, these images were taken in a healthy volunteer with normal ventricular volumes and function. These images acquired in a post mitral valve repair patient provide a typical example of the conflicting results of conventional 2D assessment. While tricuspid annular plane systolic excursion was markedly reduced, the patient did not exhibit any signs of right ventricle dysfunction and maintained right ventricle global systolic function, as confirmed by a normal 3D right ventricle ejection fraction.In this semi-professional athlete with dilated cardiomyopathy, only a moderate image quality was achievable, resulting in a poorly visualized outflow tract. Three-dimensional right ventricle analysis was successful, however demonstrating good agreement with cardiac MR results. Using the currently available software solutions, 3D right ventricular assessment became easier than ever before.Still, the key for a precise and reproducible analysis is the proper acquisition at bedside. The added clinical value of three-dimensional right high parameters is no longer a question. Beyond being a fascinating research tool, these measures are part of the state-of-the-art patient management, as well.

morphological-functional-assessment-right-ventricle-using-3d

Research

JoVE Journal

Medicine

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.

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

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.

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

Echocardiographic Assessment of the Right Heart in Mice

Transgenic and toxic models of pulmonary arterial hypertension (PAH) are widely used to study the pathophysiology of PAH and to investigate potential therapies. Given the expense and time involved in creating animal models of disease, it is critical that researchers have tools to accurately assess phenotypic expression of disease. Right ventricular dysfunction is the major manifestation of pulmonary hypertension. Echocardiography is the mainstay of the noninvasive assessment of right ventricular function in rodent models and has the advantage of clear translation to humans in whom the same tool is used. Published echocardiography protocols in murine models of PAH are lacking.
In this article, we describe a protocol for assessing RV and pulmonary vascular function in a mouse model of PAH with a dominant negative BMPRII mutation; however, this protocol is applicable to any diseases affecting the pulmonary vasculature or right heart. We provide a detailed description of animal preparation, image acquisition and hemodynamic calculation of stroke volume, cardiac output and an estimate of pulmonary artery pressure.

This article provides a protocol for the echocardiographic assessment of right ventricular size and pulmonary hypertension in mice. Applications include phenotype determination and serial assessment in transgenic and toxin-induced mouse models of cardiomyopathy and pulmonary vascular disease.

Transgenic and toxic models of pulmonary arterial hypertension (PAH) are widely used to study the pathophysiology of PAH and to investigate potential ...

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.

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

Myocardial Infarction and Functional Outcome Assessment in Pigs

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

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

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

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.

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

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.

The goal of this protocol is to noninvasively assess cardiac structural and functional changes in a mouse model of heart disease created by transverse aortic constriction, using B- and M-mode echocardiography and color/pulse wave Doppler 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 ...

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.

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

Assessment of the Anticoagulant and Anti-inflammatory Properties of Endothelial Cells Using 3D Cell Culture and Non-anticoagulated Whole Blood

In vivo, endothelial cells are crucial for the natural anticoagulation of circulating blood. Consequently, endothelial cell activation leads to blood coagulation. This phenomenon is observed in many clinical situations, like organ transplantation in the presence of pre-formed anti-donor antibodies, including xenotransplantation, as well as in ischemia/reperfusion injury. In order to reduce animal experimentation according to the 3R standards (reduction, replacement and refinement), in vitro models to study the effect of endothelial cell activation on blood coagulation would be highly desirable. However, common flatbed systems of endothelial cell culture provide a surface-to-volume ratio of 1 - 5 cm2 of endothelium per mL of blood, which is not sufficient for natural, endothelial-mediated anticoagulation. Culturing endothelial cells on microcarrier beads may increase the surface-to-volume ratio to 40 - 160 cm2/mL. This increased ratio is sufficient to ensure the &#34;natural&#34; anticoagulation of whole blood, so that the use of anticoagulants can be avoided. Here an in vitro microcarrier-based system is described to study the effects of genetic modification of porcine endothelial cells on coagulation of whole, non-anticoagulated human blood. In the described assay, primary porcine aortic endothelial cells, either wild type (WT) or transgenic for human CD46 and thrombomodulin, were grown on microcarrier beads and then exposed to freshly drawn non-anticoagulated human blood. This model allows for the measurement and quantification of cytokine release as well as activation markers of complement and coagulation in the blood plasma. In addition, imaging of activated endothelial cell and deposition of immunoglobulins, complement- and coagulation proteins on the endothelialized beads were performed by confocal microscopy. This assay can also be used to test drugs which are supposed to prevent endothelial cell activation and, thus, coagulation. On top of its potential to reduce the number of animals used for such investigations, the described assay is easy to perform and consistently reproducible.

We present an in vitro model which allows the study and analysis of coagulation in whole, non-anticoagulated blood. Anticoagulation in the system depends on the natural anticoagulation effect of healthy endothelial cells and endothelial cell activation will result in clotting.

In vivo, endothelial cells are crucial for the natural anticoagulation of circulating blood. Consequently, endothelial cell activation leads to blood ...

2D and 3D Echocardiography in the Axolotl (Ambystoma Mexicanum)

Cardiac malfunction as a result of ischemic heart disease is a major challenge, and regenerative therapies to the heart are in high demand. A few model species such as zebrafish and salamanders that are capable of intrinsic heart regeneration hold promise for future regenerative therapies for human patients. To evaluate the outcome of cardioregenerative experiments it is imperative that heart function can be monitored. The axolotl salamander (A. mexicanum) represents a well-established model species in regenerative biology attaining sizes that allows for evaluation of cardiac function. The purpose of this protocol is to establish methods to reproducibly measure cardiac function in the axolotl using echocardiography. The application of different anesthetics (benzocaine, MS-222, and propofol) is demonstrated, and the acquisition of two-dimensional (2D) echocardiographic data in both anesthetized and unanesthetized axolotls is described. 2D echocardiography of the three-dimensional (3D) heart can suffer from imprecision and subjectivity of measurements, and to alleviate this phenomenon a solid method, namely intra/inter-operator/observer analysis, to measure and minimize this bias is demonstrated. Finally, a method to acquire 3D echocardiographic data of the beating axolotl heart at a very high spatiotemporal resolution and with pronounced blood-to-tissue contrast is described. Overall, this protocol should provide the necessary methods to evaluate cardiac function and model anatomy, and flow dynamics in the axolotl using ultrasound imaging with applications in both regenerative biology and general physiological experiments.

2D and 3D Echocardiography in the Axolotl Ambystoma Mexicanum

Here we present echocardiography protocols for two-dimensional and three-dimensional image acquisition of the beating heart of the axolotl salamander (Ambystoma mexicanum), a model species in heart regeneration. These methods allow for longitudinal evaluation of cardiac function at a high spatiotemporal resolution.

Cardiac malfunction as a result of ischemic heart disease is a major challenge, and regenerative therapies to the heart are in high demand. A few model ...