This work was funded by the Hungarian Government Research Fund [GINOP-2.3.2-15-2016-00043, Sz&#237;v- &#233;s &#233;rkutat&#225;si kiv&#225;l&#243;s&#225;gk&#246;zpont (IRONHEART)].

All the patients signed informed consent before examination according to approval of the local ethical committee (OGY&#201;I/12743/2018).
1. Preparation
<ol>
	<li>Start the examination with patient preparation: ensuring at least a 4-hour fasting status, questionnaire about problems with swallowing and known upper gastrointestinal diseases.</li>
	<li>Ensure that written informed consent is read and signed.</li>
	<li>Prepare an intravenous line before the examination.</li>
	<li>Position the patient in a left lateral decubitus position.</li>
	<li>Administer mild sedation using intravenous midazolam (2.5-5 mg).</li>
	<li>Monitor ECG and oxygen saturation.</li>
</ol>
2. Image acquisition
<ol>
	<li>Visualization of the left PVs
	<ol>
		<li>Insert the probe into the oesophagus at approximately 30-40 cm from the front teeth.</li>
		<li>In the upper (or mid) transoesophageal probe position visualize the LAA using 2D image acquisition at 20-45&#176;.</li>
		<li>Turn the probe slightly clockwise and change the crystal angulation to 60-80&#176; in order to centralize the LAA on the image.</li>
		<li>Click the full volume button in order to applying full volume 3D acquisition.</li>
		<li>Adjust the image&#8217;s lateral and elevational width to display the LAA and the left upper PV. This enhances visualization of the left lateral ridge.</li>
		<li>Optimize the image quality (adjusting the depth and gain, applying harmonic imaging).</li>
		<li>Record a one-beat (if feasible, multibeat) loop with 2 cardiac cycles.</li>
		<li>Change the angulation to approximately 120&#176; on the 2D image to centralize the LAA.</li>
		<li>Turn the probe slightly counterclockwise and apply anteflexion to visualize the ostia of the left PVs.</li>
		<li>Apply color Doppler-coded imaging to confirm that both the upper and lower PVs are visible.</li>
		<li>Click the full volume button in order to applying full volume 3D acquisition.</li>
		<li>Adjust the image&#8217;s lateral and elevational width to display the left PVs. This enhances visualization of the ostia of the left upper and lower PVs and the intervenous ridge.</li>
		<li>Control dataset quality. Check the recorded dataset. If the dataset does not contain both the upper and lower PVs, change the patient position by further tilting to the lateral position, and repeat the procedure from step 2.1.8.</li>
		<li>Acquire 3D full volume datasets from the left PVs: one-beat (if feasible, multibeat) loop with 2 cardiac cycles.</li>
		<li>Confirm the visibility of PV ostia by cropping the image to the upper or lower PV ostium, respectively. The lower PV ostium requires a specifically careful confirmation. It is not unsual, that some parts of the ostium are outside the 3D dataset due to anatomical reasons, e.g. angulation or close proximity to the transducer.</li>
		<li>In case the image is not suitable for visualizing the complete PV structure, repeat the procedure from step 2.1.10. Change the lateral or elevational width of the 3D dataset, if necessary.</li>
	</ol>
	</li>
	<li>Visualization of the right PVs
	<ol>
		<li>Switch back to 2D mode and focus the image to the LAA at 45&#176; upper (or mid) oesophageal probe position.</li>
		<li>Turn the probe clockwise and move the probe head to anteflexion position in order to visualize the right PVs.</li>
		<li>Apply color Doppler-coded imaging to confirm that both the upper and lower PVs are visible.</li>
		<li>Click the full volume button in order to applying full volume 3D acquisition.</li>
		<li>Adjust the image&#8217;s lateral and elevational width to display the right PVs. This enhances visualization of the ostia of the right upper and lower PVs and the intervenous ridge. This image can be used to identify the presence of supernumerary PVs.</li>
		<li>Acquire 3D full volume datasets from the right PVs: one-beat (if feasible, multibeat) loop with 2 cardiac cycles.</li>
		<li>Confirm the visibility of PV ostia by cropping the image to the upper or lower PV ostium, respectively. The lower PV ostium requires a specifically careful confirmation. It is not unusual that some parts of the ostium are outside the 3D dataset due to anatomical reasons (e.g., angulation or close proximity to the transducer).</li>
		<li>If the dataset does not contain both the upper and lower PVs, patient position should be changed by further tilting to the right position, and the procedure should be repeated from step 2.2.1. Change the lateral or elevational width of the 3D dataset, if necessary.</li>
	</ol>
	</li>
</ol>
3. 3D image reconstruction and measurements
<ol>
	<li>Offline 3D multiplanar reconstruction
	<ol>
		<li>Activate the 3D&#160;analysis software on your scanner or&#160;workstation (Philips: activate the&#160;3DQ software in QApps panel;&#160;Tomtec: activate the 4D Cardio-view&#160;3 application; GE: activate the&#160;FlexiSlice software).</li>
		<li>Select a frame in diastolic phase for the measurements. For standardization, it is recommended to select a frame timed to the T wave.</li>
		<li>Set the two perpendicular planes to the requested structure (left lateral ridge or each PVs ostium) and adjust plane direction while the 3rd plane represents the en face view of the examined structure.</li>
		<li>On the left panel, select the measurement option. The en face view is suitable for measurements (diameter, area, distance).</li>
	</ol>
	</li>
</ol>

<ol><li>Altinkaynak, D., Koktener, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Evaluation+of+pulmonary+venous+variations+in+a+large+cohort%3A+Multidetector+computed+tomography+study+with+new+variations%5BTitle%5D)+AND+%22Wiener+klinische+Wochenschrift%22%5BJournal%5D)">Evaluation of pulmonary venous variations in a large cohort: Multidetector computed tomography study with new variations.</a> Wiener klinische Wochenschrift. 131 (19-20), 475-484 (2019).</li>
<li>Haissaguerre, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Spontaneous+initiation+of+atrial+fibrillation+by+ectopic+beats+originating+in+the+pulmonary+veins%5BTitle%5D)+AND+%22New+England+Journal+of+Medicine%22%5BJournal%5D)">Spontaneous initiation of atrial fibrillation by ectopic beats originating in the pulmonary veins.</a> New England Journal of Medicine. 339 (10), 659-666 (1998).</li>
<li>Nault, I., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Drugs+vs.+ablation+for+the+treatment+of+atrial+fibrillation%3A+the+evidence+supporting+catheter+ablation%5BTitle%5D)+AND+%22European+Heart+Journal%22%5BJournal%5D)">Drugs vs. ablation for the treatment of atrial fibrillation: the evidence supporting catheter ablation.</a> European Heart Journal. 31 (9), 1046-1054 (2010).</li>
<li>Calkins, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((HRS%2FEHRA%2FECAS+expert+consensus+statement+on+catheter+and+surgical+ablation+of+atrial+fibrillation%3A+recommendations+for+patient+selection%2C+procedural+techniques%2C+patient+management+and+follow-up%2C+definitions%2C+endpoints%2C+and+research+trial+design%3A+a+report+of+the+Heart+Rhythm+Society+%28HRS%29+Task+Force+on+Catheter+and+Surgical+Ablation+of+Atrial+Fibrillation%5BTitle%5D)+AND+%22Heart+Rhythm%22%5BJournal%5D)">HRS/EHRA/ECAS expert consensus statement on catheter and surgical ablation of atrial fibrillation: recommendations for patient selection, procedural techniques, patient management and follow-up, definitions, endpoints, and research trial design: a report of the Heart Rhythm Society (HRS) Task Force on Catheter and Surgical Ablation of Atrial Fibrillation.</a> Heart Rhythm. 9 (4), 632-696 (2012).</li>
<li>Kojodjojo, P., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Pulmonary+venous+isolation+by+antral+ablation+with+a+large+cryoballoon+for+treatment+of+paroxysmal+and+persistent+atrial+fibrillation%3A+medium-term+outcomes+and+non-randomised+comparison+with+pulmonary+venous+isolation+by+radiofrequency+ablation%5BTitle%5D)+AND+%22Heart%22%5BJournal%5D)">Pulmonary venous isolation by antral ablation with a large cryoballoon for treatment of paroxysmal and persistent atrial fibrillation: medium-term outcomes and non-randomised comparison with pulmonary venous isolation by radiofrequency ablation.</a> Heart. 96 (17), 1379-1384 (2010).</li>
<li>Packer, D. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Cryoballoon+ablation+of+pulmonary+veins+for+paroxysmal+atrial+fibrillation%3A+first+results+of+the+North+American+Arctic+Front+%28STOP+AF%29+pivotal+trial%5BTitle%5D)+AND+%22Journal+of+the+American+College+of+Cardiology%22%5BJournal%5D)">Cryoballoon ablation of pulmonary veins for paroxysmal atrial fibrillation: first results of the North American Arctic Front (STOP AF) pivotal trial.</a> Journal of the American College of Cardiology. 61 (16), 1713-1723 (2013).</li>
<li>Kuck, K., Brugada, J., Albenque, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Cryoballoon+or+Radiofrequency+Ablation+for+Atrial+Fibrillation%5BTitle%5D)+AND+%22New+England+Journal+of+Medicine%22%5BJournal%5D)">Cryoballoon or Radiofrequency Ablation for Atrial Fibrillation.</a> New England Journal of Medicine. 375 (11), 1100-1101 (2016).</li>
<li>Knecht, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Anatomical+predictors+for+acute+and+mid-term+success+of+cryoballoon+ablation+of+atrial+fibrillation+using+the+28+mm+balloon%5BTitle%5D)+AND+%22Journal+of+Cardiovascular+Electrophysiology%22%5BJournal%5D)">Anatomical predictors for acute and mid-term success of cryoballoon ablation of atrial fibrillation using the 28 mm balloon.</a> Journal of Cardiovascular Electrophysiology. 24 (2), 132-138 (2013).</li>
<li>Cabrera, J. A., Ho, S. Y., Climent, V., Sanchez-Quintana, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((The+architecture+of+the+left+lateral+atrial+wall%3A+a+particular+anatomic+region+with+implications+for+ablation+of+atrial+fibrillation%5BTitle%5D)+AND+%22European+Heart+Journal%22%5BJournal%5D)">The architecture of the left lateral atrial wall: a particular anatomic region with implications for ablation of atrial fibrillation.</a> European Heart Journal. 29 (3), 356-362 (2008).</li>
<li>Kubala, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Normal+pulmonary+veins+anatomy+is+associated+with+better+AF-free+survival+after+cryoablation+as+compared+to+atypical+anatomy+with+common+left+pulmonary+vein%5BTitle%5D)+AND+%22Pacing+and+Clinical+Electrophysiology%22%5BJournal%5D)">Normal pulmonary veins anatomy is associated with better AF-free survival after cryoablation as compared to atypical anatomy with common left pulmonary vein.</a> Pacing and Clinical Electrophysiology. 34 (7), 837-843 (2011).</li>
<li>Guler, E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Effect+of+Pulmonary+Vein+Anatomy+and+Pulmonary+Vein+Diameters+on+Outcome+of+Cryoballoon+Catheter+Ablation+for+Atrial+Fibrillation%5BTitle%5D)+AND+%22Pacing+and+Clinical+Electrophysiology%22%5BJournal%5D)">Effect of Pulmonary Vein Anatomy and Pulmonary Vein Diameters on Outcome of Cryoballoon Catheter Ablation for Atrial Fibrillation.</a> Pacing and Clinical Electrophysiology. 38 (8), 989-996 (2015).</li>
<li>Baran, J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Impact+of+pulmonary+vein+ostia+anatomy+on+efficacy+of+cryoballoon+ablation+for+atrial+fibrillation%5BTitle%5D)+AND+%22Heart+Beat+Journal%22%5BJournal%5D)">Impact of pulmonary vein ostia anatomy on efficacy of cryoballoon ablation for atrial fibrillation.</a> Heart Beat Journal. 1, 65-70 (2017).</li>
<li>Sorgente, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Pulmonary+vein+ostium+shape+and+orientation+as+possible+predictors+of+occlusion+in+patients+with+drug-refractory+paroxysmal+atrial+fibrillation+undergoing+cryoballoon+ablation%5BTitle%5D)+AND+%22Europace%22%5BJournal%5D)">Pulmonary vein ostium shape and orientation as possible predictors of occlusion in patients with drug-refractory paroxysmal atrial fibrillation undergoing cryoballoon ablation.</a> Europace. 13 (2), 205-212 (2011).</li>
<li>Chun, K. R., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((The+%27single+big+cryoballoon%27+technique+for+acute+pulmonary+vein+isolation+in+patients+with+paroxysmal+atrial+fibrillation%3A+a+prospective+observational+single+centre+study%5BTitle%5D)+AND+%22European+Heart+Journal%22%5BJournal%5D)">The 'single big cryoballoon' technique for acute pulmonary vein isolation in patients with paroxysmal atrial fibrillation: a prospective observational single centre study.</a> European Heart Journal. 30 (6), 699-709 (2009).</li>
<li>Cabrera, J. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Morphological+evidence+of+muscular+connections+between+contiguous+pulmonary+venous+orifices%3A+relevance+of+the+interpulmonary+isthmus+for+catheter+ablation+in+atrial+fibrillation%5BTitle%5D)+AND+%22Heart+Rhythm%22%5BJournal%5D)">Morphological evidence of muscular connections between contiguous pulmonary venous orifices: relevance of the interpulmonary isthmus for catheter ablation in atrial fibrillation.</a> Heart Rhythm. 6 (8), 1192-1198 (2009).</li>
<li>McLellan, A. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Pulmonary+vein+isolation%3A+the+impact+of+pulmonary+venous+anatomy+on+long-term+outcome+of+catheter+ablation+for+paroxysmal+atrial+fibrillation%5BTitle%5D)+AND+%22Heart+Rhythm%22%5BJournal%5D)">Pulmonary vein isolation: the impact of pulmonary venous anatomy on long-term outcome of catheter ablation for paroxysmal atrial fibrillation.</a> Heart Rhythm. 11 (4), 549-556 (2014).</li>
<li>Mansour, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Three-dimensional+anatomy+of+the+left+atrium+by+magnetic+resonance+angiography%3A+implications+for+catheter+ablation+for+atrial+fibrillation%5BTitle%5D)+AND+%22Journal+of+Cardiovascular+Electrophysiology%22%5BJournal%5D)">Three-dimensional anatomy of the left atrium by magnetic resonance angiography: implications for catheter ablation for atrial fibrillation.</a> Journal of Cardiovascular Electrophysiology. 17 (7), 719-723 (2006).</li>
<li>Ottaviano, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Cryoballoon+ablation+for+atrial+fibrillation+guided+by+real-time+three-dimensional+transoesophageal+echocardiography%3A+a+feasibility+study%5BTitle%5D)+AND+%22Europace%22%5BJournal%5D)">Cryoballoon ablation for atrial fibrillation guided by real-time three-dimensional transoesophageal echocardiography: a feasibility study.</a> Europace. 15 (7), 944-950 (2013).</li>
<li>Faletra, F. F., Regoli, F., Acena, M., Auricchio, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Value+of+real-time+transesophageal+3-dimensional+echocardiography+in+guiding+ablation+of+isthmus-dependent+atrial+flutter+and+pulmonary+vein+isolation%5BTitle%5D)+AND+%22Circulation+Journal%22%5BJournal%5D)">Value of real-time transesophageal 3-dimensional echocardiography in guiding ablation of isthmus-dependent atrial flutter and pulmonary vein isolation.</a> Circulation Journal. 76 (1), 5-14 (2012).</li>
<li>Coulombe, N., Paulin, J., Su, W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/pubmed?term=((Improved+in+vivo+performance+of+second-generation+cryoballoon+for+pulmonary+vein+isolation%5BTitle%5D)+AND+%22Journal+of+Cardiovascular+Electrophysiology%22%5BJournal%5D)">Improved in vivo performance of second-generation cryoballoon for pulmonary vein isolation.</a> Journal of Cardiovascular Electrophysiology. 24 (8), 919-925 (2013).</li>
</ol>

The authors report no conflicts of interest.

Here, we demonstrate a step-by-step methodology to study the PVs, their surrounding structures and anatomical characteristics with 3D echocardiography. The above described method for 3D imaging of the PVs is an easily standardizable method, which provides high quality 3D images in most patients suitable for precise measurements. Optimal quality and orientation of the acquired images are paramount for the appropriate assessment of PV anatomy. The 3D reconstructed images enhance the visualization of the PV drainage pattern...

The drainage pattern of the pulmonary veins (PV) is highly variable with 56.5% variation in the average population1. Evaluation of the PV drainage pattern is crucial when planning PV isolation (PVI), which is the most common interventional treatment of atrial fibrillation nowadays2,3,4. Although radiofrequency catheter ablation has been the standard technology for achieving PVI, the cryoballoon (CB)-based ablation technology (CA) is an alternative method requiring less procedural time. The technique is less complicated compared with radiofrequency ablation5,6, while the efficacy and safety of CA are similar to those of radiofrequency ablation7.
The rate of procedural PV occlusion by the CB and the continuous circumferential extension of tissue injury in the PV ostium determines the permanent success of PVI after CA. One of the main determinants of PV occlusion is the variation of PV anatomy. In recent, computed tomography- (CT) and cardiac MRI-based studies, several PV parameters were identified with predictive values of short and long term success rates following CA. These parameters included variations of both the PV anatomy (left common PV, supernumerary PVs8,9,10, ostial area, ovality index8,11,12,13) and its surroundings (intervenous ridge8,14,15,16, thickness of left lateral ridge8,9,17).
Although conventional 2D echocardiography is not suitable for displaying and measuring most of the above parameters, three-dimensional transesophageal echocardiography (3D TEE) seems to be an alternative tool to visualize the PVs, as demonstrated in previous literature data18,19.
Furthermore, 3D TEE prior to PVI brings additional value compared to CT or MRI, as it not only provides data on PV characteristics for procedural design, but also clarifies whether a thrombus in the left atrial appendage (LAA) is present. This investigation is especially important prior to PVI. At the same time, 3D TEE requires less time, its procedural cost is low, and it does not expose the patient and the medical staff to radiation.
In the past, several types of CBs existed with different sizes, which made it difficult to extrapolate how the various parameters of the PVs influence the success rate of CA. Today, the newly introduced second-generation CB is used for CA, which only exists in one size. Thanks to its improved cooling effect, the second-generation CB offers a much higher performance compared to the first-generation CB20, which further highlights the importance of PV anatomy and interventional planning before PVI.

<table><tbody><tr><td>4D Cardio-view 3 software</td><td>Tomtec Imaging Systems GmbH</td><td></td><td></td></tr><tr><td>Epiq 7G scanner</td><td>Philips</td><td></td><td></td></tr><tr><td>Q-Lab Software</td><td>Philips</td><td></td><td></td></tr><tr><td>X5-1 transducer</td><td>Philips</td><td></td><td></td></tr><tr><td>Vivid E95 Scanner</td><td>GE</td><td></td><td></td></tr><tr><td>4Vc-D transducer</td><td>GE</td><td></td><td></td></tr></tbody></table>

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.

Using the above-described image acquisition protocol, the first step is to visualize the left atrial appendage (LAA) using 2D acquisition (Figure 1). The probe is in the upper (or mid) transoesophageal position at 20-45&#176;. The image shows the LAA. The left lateral ridge and the left upper PV is displayed at 60-80&#176; (Figure 2), and then the 3D dataset is acquired and confirmed by cropping the dataset in order to visualize the LAA and the left lateral ridg...

Watch this Scientific Journal Video about Three-Dimensional Echocardiographic Method for the Visualization and Assessment of Specific Parameters of the Pulmonary Veins at JoVE.com

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

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 ...

three-dimensional-echocardiographic-method-for-visualization

Research

JoVE Journal

Bioengineering

2.7K Views.  University of Debrecen. De afmetingen van de longaders (PV) zijn belangrijke parameters bij het plannen van pulmonale aderisolatie. 2D transo-oesofageale echocardiografie kan slechts beperkte gegevens over de pv's opleveren; 3D-echocardiografie kan echter relevante diameters en gebieden van de PV's evalueren, evenals hun ruimtelijke relatie met omliggende structuren.

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

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

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 ...

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 ...

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 ...

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.

Mitral valve disease in pediatric cardiology is complex and can involve a combination of annular, leaflet, chordae tendineae and papillary muscle ...

Four-Dimensional Computed Tomography-Guided Valve Sizing for Transcatheter Pulmonary Valve Replacement

The measurements of the right ventricle (RV) and pulmonary artery (PA), for selecting the optimal prosthesis size for transcatheter pulmonary valve replacement (TPVR), vary considerably. Three-dimensional (3D) computed tomography (CT) imaging for device size prediction is insufficient to assess the displacement of the right ventricular outflow tract (RVOT) and PA, which could increase the risk of stent misplacement and paravalvular leak. The aim of this study is to provide a dynamic model to visualize and quantify the anatomy of the RVOT to PA over the entire cardiac cycle by four-dimensional (4D) cardiac CT reconstruction to obtain an accurate quantitative evaluation of the required valve size. In this pilot study, cardiac CT from sheep J was chosen to illustrate the procedures. 3D cardiac CT was imported into 3D reconstruction software to build a 4D sequence which was divided into eleven frames over the cardiac cycle to visualize the deformation of the heart. Diameter, cross-sectional area, and circumference of five imaging planes at the main PA, sinotubular junction, sinus, basal plane of the pulmonary valve (BPV), and RVOT were measured at each frame in 4D straightened models prior to valve implantation to predict the valve size. Meanwhile, dynamic changes in the RV volume were also measured to evaluate right ventricular ejection fraction (RVEF). 3D measurements at the end of the diastole were obtained for comparison with the 4D measurements. In sheep J, 4D CT measurements from the straightened model resulted in the same choice of valve size for TPVR (30 mm) as 3D measurements. The RVEF of sheep J from pre-CT was 62.1 %. In contrast with 3D CT, the straightened 4D reconstruction model not only enabled accurate prediction for valve size selection for TPVR but also provided an ideal virtual reality, thus presenting a promising method for TPVR and the innovation of TPVR devices.

This study assessed a new methodology with a straightened model generated from the four-dimensional cardiac computed tomography sequence to obtain the desired measurements for valve sizing in the application of transcatheter pulmonary valve replacement.

The measurements of the right ventricle (RV) and pulmonary artery (PA), for selecting the optimal prosthesis size for transcatheter pulmonary valve ...

Hemodynamic Precision in the Neonatal Intensive Care Unit using Targeted Neonatal Echocardiography

Targeted neonatal echocardiography (TnECHO) refers to the use of comprehensive echocardiographic evaluation and physiologic data to obtain accurate, reliable, and real-time information on developmental hemodynamics in sick newborns. The comprehensive assessment is based on a multiparametric approach that overcomes the reliability issues of individual measurements, allows for earlier recognition of cardiovascular compromise and promotes enhanced diagnostic precision and timely management. TnECHO-driven research has led to an enhanced understanding of the mechanisms of illness and the development of predictive models to identify at-risk populations. This information may then be used to formulate a diagnostic impression and provide individualized guidance for the selection of cardiovascular therapies. TnECHO is based on the expert consultative model in which a neonatologist, with advanced training in neonatal hemodynamics, performs comprehensive and standardized TnECHO assessments. The distinction from point of care ultrasonography (POCUS), which provides limited and brief one-time assessments, is important. Neonatal hemodynamics training is a 1-year structured program designed to optimize image acquisition, measurement analysis, and hemodynamic knowledge (physiology, pharmacotherapy) to support cardiovascular decision-making. Neonatologists with hemodynamic expertise are trained to recognize deviations from normal anatomy and appropriately refer cases of possible structural abnormalities. We provide an outline of neonatal hemodynamics training, the standardized TnECHO imaging protocol, and an example of representative echo findings in a hemodynamically significant patent ductus arteriosus.

Presented here is a protocol to perform comprehensive neonatal echocardiography by trained neonatologists in the neonatal intensive care unit. The trained individuals provide longitudinal assessments of heart function, systemic and pulmonary hemodynamics in a consultative role. The manuscript also describes the requirements to become a fully trained neonatal hemodynamics specialist.

Targeted neonatal echocardiography (TnECHO) refers to the use of comprehensive echocardiographic evaluation and physiologic data to obtain accurate, ...

ICE-Based 3D Remodeling for the Left Atrium and Pulmonary Vein

Three-Dimensional Modeling of the Left Atrium and Pulmonary Veins with a Precise Intracardiac Echocardiography Approach

Intracardiac echocardiography (ICE) is a novel tool for estimating cardiac anatomy during pulmonary vein isolation procedures, particularly the left atrium (LA) anatomy and pulmonary vein structures. ICE is widely used to establish a three-dimensional (3D) left atrial structural model during ablation procedures. However, it is unclear whether using ICE in a precise 3D modeling method can provide a more accurate left atrial 3D model and the transseptal approach. This study proposes a protocol to model the left atrium and pulmonary veins with ICE and fast anatomical mapping (FAM) catheter remodeling. It evaluates the accuracy of the models produced using the two methods through observer scoring. We included 50 patients who underwent ICE-based 3D remodeling and 45 who underwent FAM 3D remodeling based on pulmonary vein isolation procedures. The pulmonary vein antrum remodeling is estimated by comparing the antrum area acquired by remodeling and left atrial computed tomography angiography (CTA). The observer scores for the modeling in the ICE and FAM groups were 3.40 &#177; 0.81 and 3.02 &#177; 0.72 (P &#60; 0.05), respectively. The pulmonary vein antrum area obtained using the ICE- and FAM-based methods showed a correlation with the area acquired by left atrium CT. However, the 95% confidence interval bias was narrower in ICE-acquired models than in FAM-acquired models (-238 cm2 to 323 cm2 Vs. -363 cm2 to 386 cm2, respectively) using Bland-Altman analysis. Therefore, precise ICE possesses high accuracy in estimating the left atrial structure, becoming a promising approach for future cardiac structure estimation.

Author Spotlight: Advancements in Intracardiac Echocardiography for Atrial Anatomy Assessment 

Accurate intracardiac echocardiography (ICE) shows significant accuracy in estimating the left atrial structure, a prospective and promising cardiac structure estimation method. Here we propose a protocol for three-dimensional modeling of the left atrium and pulmonary veins with ICE and fast anatomical mapping (FAM) catheter remodeling.

Intracardiac echocardiography (ICE) is a novel tool for estimating cardiac anatomy during pulmonary vein isolation procedures, particularly the left ...

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

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