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.

This protocol follows the guidelines of the Semmelweis University Regional and Institutional Committee of Science and Research Ethics. The present protocol applies to a specific vendor. Although some steps remain valid regardless of the ultrasound machine and postprocessing software, important differences may exist if using other vendors&#39; solutions.
1. Technical requirements
<ol>
	<li>Utilize an echocardiography machine capable of 3D imaging.</li>
	<li>Connect a 3D transthoracic echocardiography capable phased array transducer.</li>
	<li>Apply the built-in 3-lead ECG of the ultrasound system to allow the system to synchronize the recordings and analyses to the cardiac cycle.</li>
</ol>
2. Acquisition of the 3D echocardiographic images
<ol>
	<li>Position the patient in the left lateral decubitus position (patient lying on the left side with the left arm stretched above the head).</li>
	<li>Ensure that the ECG tracing on the screen is of good quality. 
	NOTE: This is a prerequisite for postprocessing as the software will detect the different points of the cardiac cycle based on the ECG signal.</li>
	<li>Unfreeze the image, and start to examine the patient with the transducer. Visualize a conventional apical four-chamber view.</li>
	<li>Optimize the image quality by adjusting sector width to LV, lowering the depth to truncate the left atrium, and by using a slight overgain. 
	NOTE: Ensure the entire LV endo- and also the epicardial surface is visible.</li>
	<li>Press the 4D button to switch to 3D mode. 
	NOTE: By pressing the Multi-Slice... button on the touch screen, four options will be available (5, 7, 8, 12 slices) to overview the 3D dataset using standard short- and long axis cuts. If needed, transducer positioning can be corrected to ensure the inclusion of the entire LV wall thickness from apical to mitral valve level into the pyramidal 3D dataset. The use of 12 slices (with nine adjustable short-axis views) is recommended.</li>
	<li>Acquire 3D images using Multi Beat or Single Beat mode.
	<ol>
		<li>Use the Multi Beat mode to achieve higher spatial and temporal resolution, where the dataset will be reconstructed from 2, 3, 4 or 6 cardiac cycles (this can be set-up on the screen) - end-expiratory breath-hold of the patient and stable transducer positioning needed to minimize stitching artifacts. 
		NOTE: Single Beat acquisition is of lower spatial and temporal resolution; however, most modern transducers have better quality and, therefore, can be used to acquire proper 3D datasets without reconstruction to undergo further analysis. As a general recommendation, volume rates over 15 volumes per second are recommended for further analysis.</li>
		<li>When the full-volume is reconstructed from the subvolumes, and the entire LV is visible, freeze the image. Using the Cycle Select and Number of Cycles knobs, select the optimal acquired cardiac cycle(s) and press Image Store. 
		NOTE: Stitching artifacts are spatially or temporarily misaligned subvolumes next to each other. Datasets with a significant dropout of LV walls or with stitching artifacts are generally not suitable for further analysis. The quality of the already acquired 3D dataset can be double-checked using the Multi-Slice mode.</li>
	</ol>
	</li>
</ol>
3. Postprocessing to quantify LV morphology and function
<ol>
	<li>Select a 3D dataset appropriate for further analysis. 
	NOTE: This part of the protocol requires the previously acquired and saved good-quality 3D images and can be performed on the ultrasound machine and a separate workstation, either.</li>
	<li>Click on Measure | Volume, and then select 4D Auto LVQ.</li>
	<li>On the quad-screen (three apical views: four-, two-, and three-chamber views, and one short-axis view, the latter can be adjusted by a horizontal plane on long-axis views), the software asks Modify alignment of apical slices to standard views. If required, correct the apical views manually by tilting and rotation to show the corresponding standard view, thereby eliminating foreshortening. Set tilting to align the caliper with the long axis of the LV by dragging and moving the calipers on long-axis views. Set rotation by the corresponding or the Rotate All knobs on the machine or by adjusting the calipers on the short-axis image. 
	NOTE: Software recommendation can be reset by pushing the Auto Align button.</li>
	<li>After finishing view alignment, click to the next step EDV. The end-diastolic (ED) frame is automatically detected using the ECG signal, but can be manually corrected if necessary.</li>
	<li>Semi-automatic detection of LV endo- and epicardial surface
	<ol>
		<li>Select two landmark points manually on any apical views. Firstly, identify the LV apex and then the middle of the LV base (mitral annulus level) in any apical view. The algorithm will automatically contour the endocardial border of the entire LV. 
		NOTE: There are two more options: Manual, which means that two basal and one apical landmark should be set in every apical view, and Auto Init, which will automatically contour the LV without any user interaction.</li>
		<li>Check contour credibility in three apical views, three short-axis views of different levels, and a fourth user-controlled short axis, to allow visual verification of the detected surface. Contour correction is possible by manually adding points that will then be incorporated in the contour line. 
		NOTE: With Undo, the previously added point can be deleted. Reset button resets the contouring to start the entire section from the beginning. Contour visibility can be adjusted to allow the appreciation of the endocardial surface on the grey-scale image. Endocardial and epicardial contouring should be performed in an accurate and consistent manner. For a detailed recommendation, please check the following reference6.</li>
		<li>Choose the next step, which is the ESV.</li>
		<li>Repeat the same procedure (3.5.1-3.5.2) as mentioned in the previous points to identify and correct the endocardial contour on the end-systolic frame. 
		NOTE: The end-systolic (ES) frame is automatically detected using the ECG signal, but can be manually corrected if necessary. Values of end-diastolic volume (EDV), end-systolic volume (ESV), ejection fraction (EF), heart rate (HR), stroke volume (SV), cardiac output (CO) and sphericity index (SpI) are already displayed on the screen.</li>
		<li>Press Volume waveform for the next step. The software displays a dynamic 3D model of the LV and also time-volume curve as it traces the endocardial surface throughout the cardiac cycle frame-by-frame (Figure 1). 
		NOTE: Here, there is a possibility to edit the endocardial border at any frame.</li>
		<li>For the next step, press LV Mass. The software automatically contours LV epicardial contour on the end-diastolic frame and calculates LV mass (EDMass). 
		NOTE: If necessary, edit the contour of the epicardial surface by adding points to include (same method as previously described) in any short- or long-axis plane. It can be selected which contour to adjust: Endo, Epi, or Endo+Epi.</li>
		<li>Press 4D Strain ROI for the next step. The software automatically contours LV epicardial contour on the end-systolic frame and calculates LV end-systolic mass (ESMass). 
		NOTE: If necessary, edit the end-systolic contour of the epicardial surface by adding points to include (same method as previously described) in any short- or long-axis plane. ESMass should be of similar value than EDMass. This step is essential to calculate 3D strain values by speckle tracking.</li>
		<li>Press 4D Strain Results for the next step. The software visualizes the 3D myocardial tracking on multiple short- and long-axis planes and corresponding strain values of the 17 standard LV segments throughout the cardiac cycle, frame-by-frame. Time-strain curves and bull&#39;s eye plot are also displayed. The following parameters are calculated and can be demonstrated: longitudinal strain, circumferential strain, radial strain, area strain, rotation, and torsion. 
		NOTE: There is a possibility to exclude a particular LV segment from analysis if it is considered as having a low tracking quality by visual observation of images or based on the time-strain curve. However, the software recommends by default on segment approval or rejection. Color-coded strain values can be visualized on a dynamic 3D model of the LV by changing the &#34;Layout&#34;.</li>
	</ol>
	</li>
	<li>To terminate the analysis, press Approve &#38; Exit.</li>
</ol>

<ol>
	<li>Guta, A. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Three-dimensional+echocardiography+to+assess+left+ventricular+geometry+and+function.">Three-dimensional echocardiography to assess left ventricular geometry and function.</a> Expert Review of Cardiovascular Therapy. 17 (11), 801-815 (2019).</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=Current+Clinical+Applications+of+Three-Dimensional+Echocardiography:+When+the+Technique+Makes+the+Difference.">Current Clinical Applications of Three-Dimensional Echocardiography: When the Technique Makes the Difference.</a> Current Cardiology Reports. 18 (11), 109 (2016).</li><li>Lang, R. 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=Recommendations+for+cardiac+chamber+quantification+by+echocardiography+in+adults:+an+update+from+the+American+Society+of+Echocardiography+and+the+European+Association+of+Cardiovascular+Imaging.">Recommendations for cardiac chamber quantification by echocardiography in adults: an update from the American Society of Echocardiography and the European Association of Cardiovascular Imaging.</a> Journal of the American Society of Echocardiography. 28 (1), 1-39 (2015).</li><li>Matyas, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+speckle-tracking+echocardiography+with+invasive+hemodynamics+for+the+detection+of+characteristic+cardiac+dysfunction+in+type-1+and+type-2+diabetic+rat+models.">Comparison of speckle-tracking echocardiography with invasive hemodynamics for the detection of characteristic cardiac dysfunction in type-1 and type-2 diabetic rat models.</a> Cardiovascular Diabetology. 17 (1), 13 (2018).</li><li>Kovacs, 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=Impact+of+hemodialysis,+left+ventricular+mass+and+FGF-23+on+myocardial+mechanics+in+end-stage+renal+disease:+a+three-dimensional+speckle+tracking+study.">Impact of hemodialysis, left ventricular mass and FGF-23 on myocardial mechanics in end-stage renal disease: a three-dimensional speckle tracking study.</a> International Journal of Cardiovascular Imaging. 30 (7), 1331-1337 (2014).</li><li>Muraru, 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=Comprehensive+analysis+of+left+ventricular+geometry+and+function+by+three-dimensional+echocardiography+in+healthy+adults.">Comprehensive analysis of left ventricular geometry and function by three-dimensional echocardiography in healthy adults.</a> Journal of the American Society of Echocardiography. 26 (6), 618-628 (2013).</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=Relationship+between+Cardiac+Remodeling+and+Exercise+Capacity+in+Elite+Athletes:+Incremental+Value+of+Left+Atrial+Morphology+and+Function+Assessed+by+Three-Dimensional+Echocardiography.">Relationship between Cardiac Remodeling and Exercise Capacity in Elite Athletes: Incremental Value of Left Atrial Morphology and Function Assessed by Three-Dimensional Echocardiography.</a> Journal of the American Society of Echocardiography. 33 (1), 101-109 (2020).</li><li>Muraru, 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=Intervendor+Consistency+and+Accuracy+of+Left+Ventricular+Volume+Measurements+Using+Three-Dimensional+Echocardiography.">Intervendor Consistency and Accuracy of Left Ventricular Volume Measurements Using Three-Dimensional Echocardiography.</a> Journal of the American Society of Echocardiography. 31 (2), 158-168 (2018).</li><li>Kalam, K., Otahal, P., Marwick, T. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Prognostic+implications+of+global+LV+dysfunction:+a+systematic+review+and+meta-analysis+of+global+longitudinal+strain+and+ejection+fraction.">Prognostic implications of global LV dysfunction: a systematic review and meta-analysis of global longitudinal strain and ejection fraction.</a> Heart. 100 (21), 1673-1680 (2014).</li><li>Muraru, 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=Validation+of+a+novel+automated+border-detection+algorithm+for+rapid+and+accurate+quantitation+of+left+ventricular+volumes+based+on+three-dimensional+echocardiography.">Validation of a novel automated border-detection algorithm for rapid and accurate quantitation of left ventricular volumes based on three-dimensional echocardiography.</a> European Journal of Echocardiography. 11 (4), 359-368 (2010).</li><li>Doronina, 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=The+Female+Athlete's+Heart:+Comparison+of+Cardiac+Changes+Induced+by+Different+Types+of+Exercise+Training+Using+3D+Echocardiography.">The Female Athlete's Heart: Comparison of Cardiac Changes Induced by Different Types of Exercise Training Using 3D Echocardiography.</a> BioMed Research International. 2018, 3561962 (2018).</li><li>Takeuchi, 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=Measurement+of+left+ventricular+mass+by+real-time+three-dimensional+echocardiography:+validation+against+magnetic+resonance+and+comparison+with+two-dimensional+and+m-mode+measurements.">Measurement of left ventricular mass by real-time three-dimensional echocardiography: validation against magnetic resonance and comparison with two-dimensional and m-mode measurements.</a> Journal of the American Society of Echocardiography. 21 (9), 1001-1005 (2008).</li><li>Armstrong, A. C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=LV+mass+assessed+by+echocardiography+and+CMR,+cardiovascular+outcomes,+and+medical+practice.">LV mass assessed by echocardiography and CMR, cardiovascular outcomes, and medical practice.</a> JACC Cardiovasc Imaging. 5 (8), 837-848 (2012).</li><li>Olah, 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=Characterization+of+the+dynamic+changes+in+left+ventricular+morphology+and+function+induced+by+exercise+training+and+detraining.">Characterization of the dynamic changes in left ventricular morphology and function induced by exercise training and detraining.</a> International Journal of Cardiology. 277, 178-185 (2019).</li><li>Nagy, V. 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=Role+of+Right+Ventricular+Global+Longitudinal+Strain+in+Predicting+Early+and+Long-Term+Mortality+in+Cardiac+Resynchronization+Therapy+Patients.">Role of Right Ventricular Global Longitudinal Strain in Predicting Early and Long-Term Mortality in Cardiac Resynchronization Therapy Patients.</a> PLoS One. 10 (12), e0143907 (2015).</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>Badano, L. 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LV morphological and functional measurements represent cornerstones of diagnosis, management, and follow-up of cardiac diseases; moreover, they are powerful predictors of outcome. Generally, 2D echocardiography-based evaluation of the LV is recommended by current practice guidelines; however, 3D echocardiography has been proven to be more accurate as it is free from geometrical assumptions concerning LV shape7,8. Deformation imaging by speckle tracking is a robus...

The assessment of left ventricular (LV) morphology and function is the predominant purpose of general and even more specific investigations in cardiology1. The widely available and noninvasive transthoracic echocardiography (TTE), which can provide dense amounts of information, is the method of choice for a convenient, fast, and cost-effective evaluation.
Measurement of LV mass, volumes, and subsequent ejection fraction holds significant diagnostic and also prognostic value2. The more accurate a given measure is, the higher its value will be. A better correlation with gold standard cardiac magnetic resonance (CMR) imaging derived values is an ongoing chase for echocardiographic techniques. Generally, clinical practice guidelines recommend the biplane Simpson&#39;s method for LV volume and ejection fraction measurement3. However, the LV is a three-dimensional (3D) structure with an often irregular shape, and therefore, several tomographic planes will undoubtedly fail in some clinical scenarios to accurately delineate LV morphology and function. Recent advancements in ultrasonic hardware and software technology permitted the development of real-time 3D imaging, which revolutionalizes echocardiographic protocols.
Moreover, the need for a quantitative approach concerning wall motion abnormalities resulted in the rise of deformation imaging4. Strain and strain rate parameters can be calculated by speckle tracking using standard grey-scale images. 3D echocardiography may also overcome several shortcomings of a two-dimensional strain assessment5. From an expensive scientific tool, 3D echocardiography started to become a powerful technique used in everyday clinical practice, and the quantification of the LV is certainly in the first line in this breakthrough.
The present article aims to guide the reader through a detailed 3D protocol by presenting tips and tricks and also by highlighting the potential pitfalls to facilitate the widespread but technically sound use of this important technique concerning the LV.

<table><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 LVQ</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>

evaluation of left ventricular structure and function using 3d echocardiography

Three-dimensional (3D) quantification of the left ventricle (LV) provides significant added value in terms of diagnostic accuracy and precise risk stratification in various cardiac disorders. Recently, 3D echocardiography became available in routine cardiology practice; however, high-quality image acquisition and subsequent analysis have a steep learning curve. The present article aims to guide the reader through a detailed 3D protocol by presenting tips and tricks and also by highlighting the potential pitfalls to facilitate the widespread but technically sound use of this important technique concerning the LV. First and foremost, we show the acquisition of a high-quality 3D dataset with optimal spatial and temporal resolution. Then, we present the analytical steps toward a detailed quantification of the LV by using one of the most widely applied built-in software. We will quantify LV volumes, sphericity, mass and also systolic function by measuring ejection fraction and myocardial deformation (longitudinal and circumferential strain). We will discuss and provide clinical examples about the essential scenarios where the transition from a conventional echocardiographic approach to a 3D-based quantification is highly recommended.

3D analysis of the LV is feasible in the majority of patients. Case 1 is a healthy volunteer with normal ventricular volumes and function (Figure 1). Case 2 (Figure 2) is a 64-year old male patient with dilated cardiomyopathy and a wide QRS complex (160 ms) of left bundle branch block morphology. Gold standard CMR measurements were the following: end-diastolic volume: 243 mL, end-systolic volume: 160 mL, ejection fraction: 34%, L...

Watch this Scientific Journal Video about Evaluation of Left Ventricular Structure and Function using 3D Echocardiography at JoVE.com

Evaluation of Left Ventricular Structure and Function using 3D Echocardiography

In this article, we provide a step-by-step acquisition and analysis protocol for the volumetric assessment and speckle-tracking analysis of the left ventricle by 3D echocardiography, particularly focusing on practical aspects that maximize the feasibility of this technique.

Three-dimensional (3D) quantification of the left ventricle (LV) provides significant added value in terms of diagnostic accuracy and precise risk ...

evaluation-left-ventricular-structure-function-using-3d

Research

JoVE Journal

Bioengineering

3.8K Views.  Semmelweis University. In this article, we provide a step-by-step acquisition and analysis protocol for the volumetric assessment and speckle-tracking analysis of the left ventricle by 3D echocardiography, particularly focusing on practical aspects that maximize the feasibility of this technique.

Video: Evaluation of Left Ventricular Structure and Function using 3D Echocardiography

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 ...

Medicine

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.

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.

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

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.

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 ...

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 ...

Murine Echocardiography of Left Atrium, Aorta, and Pulmonary Artery

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

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

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

Three-Dimensional Echocardiographic Method for the Visualization and Assessment of Specific Parameters of the Pulmonary Veins

The dimensions of the pulmonary veins are important parameters when planning pulmonary vein isolation (PVI), especially with the cryoballoon ablation technique. Acknowledging the dimensions and anatomical variations of the pulmonary veins (PVs) may improve the outcome of the intervention. Conventional 2D transoesophageal echocardiography can only provide limited data about the dimensions of the PVs; however, 3D echocardiography can further evaluate relevant diameters and areas of the PVs, as well as their spatial relationship to surrounding structures. In previous literature data, parameters influencing the success rate of PVI have already been identified. These are the left lateral ridge, the intervenous ridge, the ostial area of the PVs and the ovality index of the ostium. Proper imaging of the PVs by 3D echocardiography is a technically challenging method. One crucial step is the collection of images. Three individual transducer positions are necessary to visualize the important structures; these are the left lateral ridge, the ostium of the PVs and the intervenous ridge of the left and right PVs. Next, 3D images are acquired and saved as digital loops. These datasets are cropped, which result in the en face views displaying spatial relationships. This step can also be employed to determine the anatomical variations of the PVs. Finally, multiplanar reconstructions are created to measure each individual parameter of the PVs.
Optimal quality and orientation of the acquired images are paramount for the appropriate assessment of PV anatomy. In the present work, we examined the 3D visibility of the PVs and the suitability of the above method in 80 patients. The aim was to provide a detailed outline of the essential steps and potential pitfalls of PV visualization and assessment with 3D echocardiography.

The dimensions of the pulmonary veins (PV) are important parameters when planning pulmonary vein isolation. 2D transoesophageal echocardiography can only provide limited data about the PVs; however, 3D echocardiography can evaluate relevant diameters and areas of the PVs, as well as their spatial relationship to surrounding structures.

The dimensions of the pulmonary veins are important parameters when planning pulmonary vein isolation (PVI), especially with the cryoballoon ablation ...

Echocardiographic Assessment of Cardiac Anatomy and Function in Adult Rats

The use of experimental animal models has become crucial in cardiovascular science. Most studies using rodent models are focused on two-dimensional imaging to study the cardiac anatomy of the left ventricle and M-mode echo to assess its dimensions. However, this could limit a comprehensive study. Herein, we describe a protocol that allows an assessment of the heart chamber size, left ventricular function (systolic and diastolic) and valvular function. A conventional medical ultrasound machine was used in this protocol and different echo views were obtained through left parasternal, apical and suprasternal windows. In the left parasternal window, the long and short axis were acquired to analyze left chamber dimensions, right ventricle and pulmonary artery dimensions, and mitral, pulmonary and aortic valve function. The apical window allows the measurement of heart chamber dimensions and evaluation of systolic and diastolic parameters. It also allows Doppler assessment with detection and quantification of heart valve disturbances (regurgitation or stenosis). Different segments and walls of the left ventricle are visualized throughout all views. Finally, the ascending aorta, aortic arch, and descending aorta can be imaged through the suprasternal window. A combination of ultrasound imaging, Doppler flow and tissue Doppler assessment have been obtained to study cardiac morphology and function. This represents an important contribution to improve the assessment of cardiac function in adult rats with impact for research using these animal models.

A non-invasive protocol for transthoracic echocardiography assessment of cardiac anatomy and function for adult rats is presented in the current study. The heart valves, all four cardiac chambers and the ascending aorta, aortic arch and descending aorta are studied in detail.

The use of experimental animal models has become crucial in cardiovascular science. Most studies using rodent models are focused on two-dimensional ...

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

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

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

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 ...

The Use of 3D Echocardiography in Surgical Planning of the Mitral Valve in Pediatric Cardiology

Mitral valve disease in pediatric cardiology is complex and can involve a combination of annular, leaflet, chordae tendineae and papillary muscle abnormalities. Transthoracic two-dimensional echocardiography (2DE) remains the primary diagnostic imaging technique utilized in pediatric surgical planning. However, given that the mitral valve is a three-dimensional (3D) structure, the addition of 3D echocardiography (3DE) to better define the mechanisms of stenosis and/or regurgitation is advantageous. Transthoracic 3DE technology has improved with advances in probe technology and ultrasound scanners, producing images with good spatial resolution and adequate temporal resolution. Specifically, the addition of pediatric 3D transducers with higher frequencies and a smaller footprint provides better 3DE imaging in children. Improved efficiency of 3DE acquisition and analysis allow 3D assessment of the mitral valve to be more easily integrated by the sonographer, the cardiologist and the surgeon in mitral valve assessment. This improvement was also made possible by the postprocessing software optimization.
In this method paper, we aim to describe the transthoracic 3DE assessment of the mitral valve in children and its use in the surgical planning of pediatric mitral valve disease. Firstly, the 3DE assessment begins by selecting the correct probe and by obtaining a view of the mitral valve. Then, the appropriate data acquisition method should be selected based on the individual patient. Next, optimization of the data set is critical in order to properly balance spatial and temporal resolution. During live scanning or following acquisition, the data set can be cropped using innovative tools that allow the user to quickly obtain an infinite number of cut planes or volumetric reconstructions. The cardiologist and surgeon can view the mitral valve en face; thus, accurately reconstructing its morphology in order to support medical or surgical planning. Finally, a review of some clinical applications is proposed, showing examples in pediatric mitral valve managements.

3D echocardiography of the mitral valve in pediatric cardiology produces full anatomic reconstructions that contribute to improved surgical management. Here, we outline a protocol for 3D acquisition and post-processing of the mitral valve in pediatric cardiology.