The authors thank the echocardiographic study subject for volunteering in the video as well as Witten/Herdecke University and HELIOS Research Center (HRC-ID 000416 assigned to Kai O. Hensel) for funding.

The protocol content has been ethically approved by the Witten/Herdecke University Ethics Committee.
1. Technical Requirements
<ol>
	<li>Utilize an echocardiography device featuring speckle tracking technology equipped with an adequate sector array tissue harmonic imaging transducer.</li>
	<li>During image acquisition, record and connect a standard 3-lead EKG directly to the echocardiography device in order to synchronize echocardiographic motion images to electromechanical activity. This is mandatory for timing purposes during subsequent postprocessing analyses. Connect the study subject to the EKG and unfreeze the ultrasound image to start detecting the EKG signal.</li>
	<li>Record digital loops as explained in detail below (steps 2.1-2.5) and store the data as moving images in DICOM format on an external disk. Subsequently, transfer the files to an off-line workstation.</li>
	<li>Perform post-processing analyses using appropriate software as outlined in detail below (steps 3.1-3.13).</li>
</ol>
2. Recording of Echocardiographic Digital Loops
<ol>
	<li>Examine the patient in the left lateral decubitus position (patient lying on the left side with the left arm stretched above the head). 
	NOTE: This part of the protocol requires the patient/study subject to be present.</li>
	<li>Alternatively, when combining STE with stress echocardiography modalities such as a bicycle ergometer, ensure that the patient is in a 45-degree upright position. In this case, utilize a standard bicycle ergometry device and perform standard stress echocardiography testing as previously described11. During the recording of echocardiographic images, tilt the ergometer to achieve a left lateral body position in order to minimize artifacts by interfering lung tissue.</li>
	<li>Take special care to optimize image quality to guarantee accurate assessment of myocardial deformation. To do so, adjust the frame rate between 60 and 80 frames per second using the &#34;adjust frame rate&#34; option. Furthermore, pay attention to include all aspects of the myocardial structures that shall be analyzed throughout the entirety of the cardiac cycle.</li>
	<li>Obtain cross-sectional two-dimensional greyscale B-mode images in standard apical long axis and parasternal short axis planes as described by the European Association of Cardiovascular Imaging and the American Society of Echocardiography12. Record several consecutive cardiac cycles (actually only one is necessary, recording of at least three cardiac cycles is advised in order to be able to choose the one with the best image quality during subsequent post processing) in each of the following planes:
	<ol>
		<li>For the assessment of longitudinal &#949; and SR, capture standard apical 4-, 3-, and 2-chamber views as previously described12. To do so, position the transducer at the apex of the heart near the apical impulse (usually between the 3rd and 5th intercostal space and between the mid-clavicular and anterior axillary line). Aim towards the right shoulder and angulate the transducer until all anatomical structures of interest become visible.</li>
		<li>Record images in the parasternal short axis view at the level of the mitral valve, the papillary muscles and the apex to detect circumferential &#949; and SR as well as radial &#949; and SR as described elsewhere in detail12. To do so, place the probe at the left parasternal border at the 2nd or 3rd intercostal space and angulate until you obtain a cross-sectional perpendicular view of the LV.</li>
	</ol>
	</li>
	<li>When combining STE with cardiac stress testing such as bicycle ergometry or any other functional testing modality requiring serial measurements (see step 2.2), repeat step 2.4 at each desired time point.</li>
</ol>
3. Postprocessing Analysis
NOTE: This part of the protocol includes the evaluation and interpretation of the recorded echocardiographic images. It does not require the patient to be present and can be performed at any time following the previous part of the procedure.
<ol>
	<li>Utilizing the quantitative echocardiography analysis software, click &#39;File&#39; and &#39;Open&#39; and chose the desired echocardiographic study data. Select a patient/study and pick an echocardiographic plane that shall be analyzed.</li>
	<li>Click the &#39;Q&#39;-icon in the right lower corner of the selected image. Next, press the &#39;aCMQ&#39; button on the left.</li>
	<li>Chose the cardiac cycle of the highest image quality by using the green &#39;QRS&#39; skip keys at the bottom of the screen. Use the keyboard space bar to play and pause the loop.</li>
	<li>Select a region of interest (ROI) to be analyzed by confirming the echocardiographic view on the left side of the screen. Next, have the software automatically detect the timing of end-diastole and suggest a ROI. 
	NOTE: A first speckle tracking analysis is subsequently being computed by the software. Segmental and global &#949; curves are displayed on the bottom of the screen.</li>
	<li>Click &#39;Strain rate&#39; below the graphs to visualize segmental and global SR.</li>
	<li>Visually verify the tracking quality suggested by the software. 
	NOTE: To do so, critically control whether all aspects of the myocardium to be analyzed are completely covered by the ROI during the entirety of the cardiac cycle. Avoid including surrounding non-myocardial tissues into the ROI.</li>
	<li>If necessary, manually reposition the entire ROI or single aspects of it, or even re-draw the ROI completely (see 3.8-3.9) in order to guarantee exact measurements. 
	NOTE: Optionally, set the ROI to be transparent to adjust the ROI coverage to the appropriate position and width of the myocardium.</li>
	<li>In the apical 4-, 3-, and 2-chamber view, have the software automatically determine a possible ROI dividing the myocardium into seven segments.
	<ol>
		<li>In case ROI re-definition is necessary, click &#39;Draw&#39; on the left and start out tagging the endocardial border at three reference points: the two opposing insertion points of the AV valve and the LV wall starting with the basal infero-septal/ basal infero-lateral/basal inferior part of the valve finishing with the center of the apex. Ensure that both endpoints of the tracked-endocardium are on the same level completely excluding the valvular tissue.</li>
		<li>If repositioning is necessary in order to optimize position and width of the ROI, click &#39;Edit&#39; on the left side of the screen. Move each segment margin as well as the endocardial and epicardial borders individually with the cursor. Utilize an orthogonal line pointing towards the apex for navigation/orientation when moving the ROI in its entirety.</li>
		<li>Finally, start the speckle tracking re-analysis by pressing the &#39;Compute&#39; button on the left side of the screen. 
		NOTE: The software now automatically detects &#34;acoustic markers&#34;, which deflect myocardial ultrastructures corresponding to myocardial fiber organization in their movement throughout the contraction and relaxation of the myocardium. These acoustic markers are traced through the entire duration of a complete cardiac cycle. The necessary calculation may take seconds to minutes. &#949; and SR are calculated by the software and presented in a numeric and graphic manner.</li>
	</ol>
	</li>
	<li>In the parasternal view, have the software automatically suggest a predefined ROI. Adjust this ROI manually, dividing the myocardium into six segments. 
	NOTE: The width of the ROI, should exactly match the thickness of the myocardium. Where necessary, optimize position and width of the ROI as described in 3.8.2. A dot in the center of the ROI may be utilized for navigation/orientation when moving the ROI in its entirety.
	<ol>
		<li>Next, start the speckle tracking re-analysis by pressing the &#39;Compute&#39; button on the left side of the screen.</li>
	</ol>
	</li>
	<li>Chose segmental and global &#949; and SR to be displayed in curves or the comprehensive bull&#39;s eye format. To do so, click the &#39;Preferences&#39; button at the bottom left corner of the screen. Different types of waveforms and displaying options can be selected in this menu.</li>
	<li>If manual repositioning of the ROI is not sufficient to achieve appropriate overall speckle tracking quality, start over from 3.1 and redefine the ROI or consider selecting a different cardiac cycle prior to continuing to the next step.</li>
	<li>Save and export the data for subsequent statistical analyses. If desired, cine loops or still frames can be exported as illustrations. To do so, click &#39;Export&#39; at the bottom left corner of the screen and select the desired format and file directory.</li>
</ol>

<ol>
	<li>Leischik, R., Dworrak, B., Hensel, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intraobserver+and+interobserver+reproducibility+for+radial,+circumferential+and+longitudinal+strain+echocardiography.">Intraobserver and interobserver reproducibility for radial, circumferential and longitudinal strain echocardiography.</a> Open Cardiovasc. Med. J. 8, 102-109 (2014).</li><li>Smiseth, O. A., Torp, H., Opdahl, A., Haugaa, K. H., Urheim, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Myocardial+strain+imaging:+how+useful+is+it+in+clinical+decision+making?.">Myocardial strain imaging: how useful is it in clinical decision making?.</a> Eur Heart J. , (2015).</li><li>Opdahl, A., Helle-Valle, T., Skulstad, H., Smiseth, O. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Strain,+strain+rate,+torsion,+and+twist:+echocardiographic+evaluation.">Strain, strain rate, torsion, and twist: echocardiographic evaluation.</a> Curr. Cardiol. Rep. 17, 568 (2015).</li><li>Kukulski, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+of+acutely+ischemic+myocardium+using+ultrasonic+strain+measurements.+A+clinical+study+in+patients+undergoing+coronary+angioplasty.">Identification of acutely ischemic myocardium using ultrasonic strain measurements. A clinical study in patients undergoing coronary angioplasty.</a> J. Am. Coll. Cardiol. 41, 810-819 (2003).</li><li>Suffoletto, M. S., Dohi, K., Cannesson, M., Saba, S., Gorcsan, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Novel+speckle-tracking+radial+strain+from+routine+black-and-white+echocardiographic+images+to+quantify+dyssynchrony+and+predict+response+to+cardiac+resynchronization+therapy.">Novel speckle-tracking radial strain from routine black-and-white echocardiographic images to quantify dyssynchrony and predict response to cardiac resynchronization therapy.</a> Circulation. 113, 960-968 (2006).</li><li>Hensel, K. O., 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=Subclinical+Alterations+of+Cardiac+Mechanics+Present+Early+in+the+Course+of+Pediatric+Type+1+Diabetes+Mellitus:+A+Prospective+Blinded+Speckle+Tracking+Stress+Echocardiography+Study.">Subclinical Alterations of Cardiac Mechanics Present Early in the Course of Pediatric Type 1 Diabetes Mellitus: A Prospective Blinded Speckle Tracking Stress Echocardiography Study.</a> J Diabetes Res. 2016, 2583747 (2016).</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, 1673-1680 (2014).</li><li>Hensel, K. O., Grimmer, F., Jenke, A. C., Wirth, S., Heusch, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+influence+of+real-time+blood+glucose+levels+on+left+ventricular+myocardial+strain+and+strain+rate+in+pediatric+patients+with+type+1+diabetes+mellitus+-+a+speckle+tracking+echocardiography+study.">The influence of real-time blood glucose levels on left ventricular myocardial strain and strain rate in pediatric patients with type 1 diabetes mellitus - a speckle tracking echocardiography study.</a> BMC Cardiovasc. Disord. 15, 175 (2015).</li><li>Kurt, M., Tanboga, I. H., Aksakal, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Two-Dimensional+Strain+Imaging:+Basic+principles+and+Technical+Consideration.">Two-Dimensional Strain Imaging: Basic principles and Technical Consideration.</a> Eurasian J Med. 46, 126-130 (2014).</li><li>Cameli, M., Lisi, M., Righini, F. M., Mondillo, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Novel+echocardiographic+techniques+to+assess+left+atrial+size,+anatomy+and+function.">Novel echocardiographic techniques to assess left atrial size, anatomy and function.</a> Cardiovasc. Ultrasound. 10 (4), (2012).</li><li>Pellikka, P. A., Nagueh, S. F., Elhendy, A. A., Kuehl, C. A., Sawada, S. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=American+Society+of+Echocardiography+recommendations+for+performance,+interpretation,+and+application+of+stress+echocardiography.">American Society of Echocardiography recommendations for performance, interpretation, and application of stress echocardiography.</a> J. Am. Soc. Echocardiogr. 20, 1021-1041 (2007).</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> J. Am. Soc. Echocardiogr. 28, 1-39 (2015).</li><li>Curtis, J. 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=The+association+of+left+ventricular+ejection+fraction,+mortality,+and+cause+of+death+in+stable+outpatients+with+heart+failure.">The association of left ventricular ejection fraction, mortality, and cause of death in stable outpatients with heart failure.</a> J. Am. Coll. Cardiol. 42, 736-742 (2003).</li><li>Liebson, P. R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Echocardiographic+correlates+of+left+ventricular+structure+among+844+mildly+hypertensive+men+and+women+in+the+Treatment+of+Mild+Hypertension+Study+(TOMHS).">Echocardiographic correlates of left ventricular structure among 844 mildly hypertensive men and women in the Treatment of Mild Hypertension Study (TOMHS).</a> Circulation. 87, 476-486 (1993).</li><li>Hensel, K. O., Jenke, A., Leischik, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Speckle-tracking+and+tissue-Doppler+stress+echocardiography+in+arterial+hypertension:+a+sensitive+tool+for+detection+of+subclinical+LV+impairment.">Speckle-tracking and tissue-Doppler stress echocardiography in arterial hypertension: a sensitive tool for detection of subclinical LV impairment.</a> Biomed Res Int. , 472562 (2014).</li><li>Gorcsan, J., Tanaka, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Echocardiographic+assessment+of+myocardial+strain.">Echocardiographic assessment of myocardial strain.</a> J. Am. Coll. Cardiol. 58, 1401-1413 (2011).</li><li>Holmes, A. A., Taub, C. C., Garcia, M. J., Shan, J., Slovut, D. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Increased+Apical+Rotation+in+Severe+Aortic+Stenosis+is+Associated+with+Reduced+Survival:+A+Speckle-Tracking.">Increased Apical Rotation in Severe Aortic Stenosis is Associated with Reduced Survival: A Speckle-Tracking.</a> J. Am. Soc. Echocardiogr. , (2015).</li><li>Auger, 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=Effect+of+cardiac+resynchronization+therapy+on+the+sequence+of+mechanical+activation+assessed+by+two-dimensional+radial+strain+imaging.">Effect of cardiac resynchronization therapy on the sequence of mechanical activation assessed by two-dimensional radial strain imaging.</a> Am. J. Cardiol. 113, 982-987 (2014).</li><li>To, 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=Strain-time+curve+analysis+by+speckle+tracking+echocardiography+in+cardiac+resynchronization+therapy:+Insight+into+the+pathophysiology+of+responders+vs.+non-responders.">Strain-time curve analysis by speckle tracking echocardiography in cardiac resynchronization therapy: Insight into the pathophysiology of responders vs. non-responders.</a> Cardiovasc. Ultrasound. 14 (14), (2016).</li><li>Seo, 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=Three-dimensional+propagation+imaging+of+left+ventricular+activation+by+speckle-tracking+echocardiography+to+predict+responses+to+cardiac+resynchronization+therapy.">Three-dimensional propagation imaging of left ventricular activation by speckle-tracking echocardiography to predict responses to cardiac resynchronization therapy.</a> J. Am. Soc. Echocardiogr. 28, 606-614 (2015).</li><li>Trache, T., Stobe, S., Tarr, A., Pfeiffer, D., Hagendorff, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+agreement+between+3D,+standard+2D+and+triplane+2D+speckle+tracking:+effects+of+image+quality+and+3D+volume+rate.">The agreement between 3D, standard 2D and triplane 2D speckle tracking: effects of image quality and 3D volume rate.</a> Echo Res Pract. 1, 71-83 (2014).</li><li>Sanchez, A. 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=Effects+of+frame+rate+on+two-dimensional+speckle+tracking-derived+measurements+of+myocardial+deformation+in+premature+infants.">Effects of frame rate on two-dimensional speckle tracking-derived measurements of myocardial deformation in premature infants.</a> Echocardiography. 32, 839-847 (2015).</li><li>Hensel, K. O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Non-ischemic+diabetic+cardiomyopathy+may+initially+exhibit+a+transient+subclinical+phase+of+hyperdynamic+myocardial+performance.">Non-ischemic diabetic cardiomyopathy may initially exhibit a transient subclinical phase of hyperdynamic myocardial performance.</a> Medical Hypotheses. 94, 7-10 (2016).</li></ol>

The authors have nothing to disclose.

Significance of the technique with respect to alternative methods
The current gold standard for the echocardiographic assessment of LV systolic function is the LV ejection fraction (EF)13. However, determination of EF is based on a simplistic approach that is closely correlated to the radial component of myocardial contraction but does not take into consideration the important longitudinal and circumferential planes. Hence, EF oversimplifies the three-dimensional co...

Scientific and clinical scenarios in cardiovascular medicine are more and more addressed by continuous variables and cutoff values rather than simplistic &#34;yes or no&#34; algorithms. Imaging techniques have evolved to be able to assess cardiac function in ever increasing detail. Speckle tracking echocardiography (STE) is an emerging diagnostic tool for the quantitative evaluation of myocardial performance. While conventional echocardiography is limited by subjective image interpretation and a strong dependence on the individual examiner&#39;s expertise, STE has been introduced as a reproducible and more objective method to quantify global and regional systolic and diastolic function1,2.
Left ventricular (LV) myocardial deformation &#8212; longitudinal and circumferential shortening as well as radial thickening in systole and vice versa in diastole &#8212; can be described measuring the parameters strain (&#949;) and strain rate (SR). &#949; is a dimensionless percent change in myocardial length. SR is a time derivate of &#949;3. These important indices of myocardial function have been shown to be able to identify myocardial ischemia4, predict response to cardiac resynchronization therapy5 and to detect subclinical myocardial dysfunction while conventional echocardiographic parameters still remain normal6. In a systematic meta-analysis, global longitudinal &#949;, the most frequently used quantitative LV systolic function parameter, has been shown to have superior prognostic value for the prediction of major adverse cardiac events then LV ejection fraction (EF), the current gold standard for the assessment of LV systolic function7. Even very subtle alterations such as the effect of short term metabolic changes on myocardial mechanics in asymptomatic patients can be detected utilizing STE8.
Technically, STE uses greyscale 2D or 3D B-mode motion images recorded in standard echocardiography views. Several consecutive cardiac cycles are recorded in apical 4-, 3- and 2-chamber views to measure longitudinal deformation and in the parasternal short axis view for circumferential and radial deformation9. Moreover, by capturing the short axis view at the level of the mitral valve, the papillary muscles and the apex, LV torsion can be assessed3. Subsequently to image acquisition and storage as digital loops, myocardial deformation is measured on an off-line work station or on the ultrasound device itself. The software detects unique myocardial pixel patterns in the recorded greyscale images, so-called &#34;speckles&#34; and traces them throughout the analyzed cardiac cycle. Vectors are measured and deformation parameters are subsequently calculated. This way regional and global myocardial deformation can be assessed in systole and diastole for both the left and right ventricle and atrium10.

<table><tbody><tr><td>Phillips iE33 ultrasound system</td><td>Philips Healthcare</td><td></td><td>http://www.umiultrasound.com/ultrasound-machine/philips/ie33</td></tr><tr><td>S5-1 broadband sector array transducer&amp;nbsp;</td><td>Philips Healthcare</td><td></td><td>5-1 MHz, http://www.usa.philips.com/healthcare/product/HC989605412081/s5-1</td></tr><tr><td>QLAB Advanced Quantification Software Version 10.5</td><td>Philips Healthcare</td><td></td><td>Q-App: Automated Cardiac Motion Quantification (aCMQ), www.philips.com/QLAB-cardiology</td></tr><tr><td>Xcelera R3.3L1 (Version 3.3.1.1103)&amp;nbsp;</td><td>Philips Healthcare</td><td></td><td>http://www.usa.philips.com/healthcare/product/HC830038/xcelera-r41-cardiology-information-management-system</td></tr></tbody></table>

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.

The principle parameters for the quantitative assessment of myocardial performance are ε and SR. Technically, all cardiac chambers can be analyzed using STE. However, since speckle tracking methodology has been mostly used to study the LV, the focus of this article is on LV myocardial mechanics. Generally, longitudinal ε and SR are the most commonly assessed LV deformation parameters. Longitudinal ε and SR describe systolic shortening (and diastolic lengthening) of the myocardium. Henc...

Watch this Scientific Journal Video about Transthoracic Speckle Tracking Echocardiography for the Quantitative Assessment of Left Ventricular Myocardial Deformation at JoVE.com

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

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 ...

transthoracic-speckle-tracking-echocardiography-for-quantitative

Research

JoVE Journal

Medicine

19.4K Views.  Witten/Herdecke University.  Speckle-tracking echocardiografie is een opkomende diagnostische beeldvorming techniek voor de kwantitatieve beoordeling van wereldwijde en regionale hartspierprestatie. Standaard weergave echocardiografische bewegende beelden worden opgenomen en vervorming parameters worden vervolgens gemeten met behulp van geautomatiseerde continue frame per frame van tracking en bewegingsanalyse van spikkels binnen de B-modus beelden van de hartspier. 

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

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 ...

High-frequency High-resolution Echocardiography: First Evidence on Non-invasive Repeated Measure of Myocardial Strain, Contractility, and Mitral Regurgitation in the Ischemia-reperfused Murine Heart

Ischemia-reperfusion (IR) was surgically performed in murine hearts which were then subjected to repeated imaging to monitor temporal changes in functional parameters of key clinical significance. Two-dimensional movies were acquired at high frame rate (8 kHz) and were utilized to estimate high-quality myocardial strain. Two-dimensional elastograms (strain images), as well as strain profiles, were visualized. Results were powerful in quantitatively assessing IR-induced changes in cardiac events including left-ventricular (LV) contraction, LV relaxation and isovolumetric phases of both pre-IR and post-IR beating hearts in intact mice. In addition, compromised sector-wise wall motion and anatomical deformation in the infarcted myocardium were visualized.  The elastograms were uniquely able to provide information on the following parameters in addition to standard physiological indices that are known to be affected by myocardial infarction in the mouse: internal diameters of mitral valve orifice and aorta, effective regurgitant orifice, myocardial strain (circumferential as well as radial), turbulence in blood flow pattern as revealed by the color Doppler movies and velocity profiles, asynchrony in LV sector, and changes in the length and direction of vectors demonstrating slower and asymmetrical wall movement. This work emphasizes on the visual demonstration of how such analyses are performed. 

High-frequency High-resolution Echocardiography: First Evidence on Non-invasive Repeated Measure of Myocardial Strain, Contractility, and Mitral Regurgitation in the Ischemia-reperfused Murine Heart 

High frequency Doppler ultrasound is a novel technology for assessing regional myocardial function. This work presents first evidence demonstrating applicability of this versatile imaging platform for the repeated measure of myocardial strain, dp/dt, and mitral regurgitation in the ischemia-reperfused (IR) murine heart.

Ischemia-reperfusion (IR) was surgically performed in murine hearts which were then subjected to repeated imaging to monitor temporal changes in ...

Magnetic Resonance Derived Myocardial Strain Assessment Using Feature Tracking 

Purpose: An accurate and practical method to measure parameters like strain in myocardial tissue is of great clinical value, since it has been shown, that strain is a more sensitive and earlier marker for contractile dysfunction than the frequently used parameter EF. Current technologies for CMR are time consuming and difficult to implement in clinical practice. Feature tracking is a technology that can lead to more automization and robustness of quantitative analysis of medical images with less time consumption than comparable methods.
Methods: An automatic or manual input in a single phase serves as an initialization from which the system starts to track the displacement of individual patterns representing anatomical structures over time. The specialty of this method is that the images do not need to be manipulated in any way beforehand like e.g. tagging of CMR images.
Results: The method is very well suited for tracking muscular tissue and with this allowing quantitative elaboration of myocardium and also blood flow.
Conclusions: This new method offers a robust and time saving procedure to quantify myocardial tissue and blood with displacement, velocity and deformation parameters on regular sequences of CMR imaging. It therefore can be implemented in clinical practice.

Magnetic Resonance Derived Myocardial Strain Assessment Using Feature Tracking

An accurate and practical method to measure parameters like strain in myocardial tissue is of great clinical value, since it has been shown, that strain is a more sensitive and earlier marker for contractile dysfunction than the frequently used parameter EF.

Purpose: An accurate and practical method to measure parameters like strain in myocardial tissue is of great clinical value, since it has been shown, that ...

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 ...

Displacement Analysis of Myocardial Mechanical Deformation (DIAMOND) Reveals Segmental Heterogeneity of Cardiac Function in Embryonic Zebrafish

Zebrafish are increasingly utilized as a model organism for cardiomyopathies and regeneration. Current methods evaluating cardiac function fail to reliably detect segmental mechanics and are not readily feasible in zebrafish. Here we present a semiautomated, open-source method for the quantitative assessment of four-dimensional (4D) segmental cardiac function: displacement analysis of myocardial mechanical deformation (DIAMOND). Transgenic embryonic zebrafish were imaged in vivo using a light-sheet fluorescence microscopy system with 4D cardiac motion synchronization. Acquired 3D digital hearts were reconstructed at end-systole and end-diastole, and the ventricle was manually segmented into binary datasets. Then, the heart was reoriented and isotropically resampled along the true short axis, and the ventricle was evenly divided into eight portions (I&#8211;VIII) along the short axis. Due to the different resampling planes and matrices at end-systole and end-diastole, a transformation matrix was applied for image registration to restore the original spatial relationship between the resampled systolic and diastolic image matrices. After image registration, the displacement vector of each segment from end-systole to end-diastole was calculated based on the displacement of mass centroids in three dimensions (3D). DIAMOND shows that basal myocardial segments adjacent to the atrioventricular canal undergo the highest mechanical deformation and are the most susceptible to doxorubicin-induced cardiac injury. Overall, DIAMOND provides novel insights into segmental cardiac mechanics in zebrafish embryos beyond traditional ejection fraction (EF) under both physiological and pathological conditions.

Displacement Analysis of Myocardial Mechanical Deformation DIAMOND Reveals Segmental Heterogeneity of Cardiac Function in Embryonic Zebrafish

The goal of this protocol is to detail a novel method for the assessment of segmental cardiac function in embryonic zebrafish under both physiological and pathological conditions.

Zebrafish are increasingly utilized as a model organism for cardiomyopathies and regeneration. Current methods evaluating cardiac function fail to ...

Developmental Biology

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 ...

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.

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 ...

Bioengineering

Quantification of Mouse Heart Left Ventricular Function, Myocardial Strain, and Hemodynamic Forces by Cardiovascular Magnetic Resonance Imaging

Mouse models have contributed significantly to understanding genetic and physiological factors involved in healthy cardiac function, how perturbations result in pathology, and how myocardial diseases may be treated. Cardiovascular magnetic resonance imaging (CMR) has become an indispensable tool for a comprehensive in vivo assessment of cardiac anatomy and function. This protocol shows detailed measurements of mouse heart left ventricular function, myocardial strain, and hemodynamic forces using 7-Tesla CMR. First, animal preparation and positioning in the scanner are demonstrated. Survey scans are performed for planning imaging slices in various short- and long-axis views. A series of prospective ECG-triggered short-axis (SA) movies (or CINE images) are acquired covering the heart from apex to base, capturing end-systolic and end-diastolic phases. Subsequently, single-slice, retrospectively gated CINE images are acquired in a midventricular SA view, and in 2-, 3-, and 4-chamber views, to be reconstructed into high-temporal resolution CINE images using custom-built and open-source software. CINE images are subsequently analyzed using dedicated CMR image analysis software.
Delineating endomyocardial and epicardial borders in SA end-systolic and end-diastolic CINE images allows for the calculation of end-systolic and end-diastolic volumes, ejection fraction, and cardiac output. The midventricular SA CINE images are delineated for all cardiac time frames to extract a detailed volume-time curve. Its time derivative allows for the calculation of the diastolic function as the ratio of the early filling and atrial contraction waves. Finally, left ventricular endocardial walls in the 2-, 3-, and 4-chamber views are delineated using feature-tracking, from which longitudinal myocardial strain parameters and left ventricular hemodynamic forces are calculated. In conclusion, this protocol provides detailed in vivo quantification of the mouse cardiac parameters, which can be used to study temporal alterations in cardiac function in various mouse models of heart disease.

This study describes a comprehensive cardiovascular magnetic resonance imaging (CMR) protocol to quantify the left ventricular functional parameters of the mouse heart. The protocol describes the acquisition, post-processing, and analysis of the CMR images as well as assessment of different cardiac functional parameters.

Mouse models have contributed significantly to understanding genetic and physiological factors involved in healthy cardiac function, how perturbations ...

Transthoracic Echocardiographic Examination in the Rabbit Model

Large animal models such as the rabbit are valuable for translational preclinical research. Rabbits have a similar cardiac electrophysiology compared to that of humans and that of other large animal models such as dogs and pigs. However, the rabbit model has the additional advantage of lower maintenance costs compared to other large animal models. The longitudinal evaluation of cardiac function using echocardiography, when appropriately implemented, is a useful methodology for preclinical assessment of novel therapies for heart failure with reduced ejection fraction (e.g. cardiac regeneration). The correct use of this non-invasive tool requires the implementation of a standardized examination protocol following international guidelines. Here we describe, step by step, a detailed protocol supervised by veterinary cardiologists for performing echocardiography in the rabbit model, and demonstrate how to correctly obtain the different echocardiographic views and imaging planes, as well as the different imaging modes available in a clinical echocardiography system routinely used in human and veterinary patients.

Here we describe, step by step, a detailed protocol for performing echocardiography in the rabbit model. We show how to correctly obtain the different echocardiographic views and imaging planes, as well as the different imaging modes available in a clinical echocardiography system routinely used in human and veterinary patients.

Large animal models such as the rabbit are valuable for translational preclinical research. Rabbits have a similar cardiac electrophysiology compared to ...

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

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

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

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

Samenvatting

Meer video's verkennen

Hoofdstukken in deze video