This material is the result of work supported with resources and the use of the facilities at the Clement J. Zablocki Veterans Affairs Medical Center in Milwaukee, Wisconsin.

The Institutional Review Board of the Clement J. Zablocki Veterans Affairs Medical Center approved the protocols. Written informed consent was waived because invasive cardiac monitoring and TEE are routinely used in all patients undergoing cardiac surgery in our institution. Patients with relative or absolute contraindications for TEE, those undergoing repeat median sternotomy or emergency surgery, and those with atrial or ventricular tachyarrhythmias were excluded from participation.
1. Anesthesia
<ol>
	<li>Provide each patient with intravenous midazolam (1 to 3 mg) and fentanyl (50 to 150 &#181;g) for conscious sedation before surgery.</li>
	<li>Use local anesthesia (subcutaneous 1% lidocaine) for insertion of intravenous and radial artery catheters. Test the quality of the local anesthesia with a pinprick.</li>
	<li>Ensure that the patient receives supplemental oxygen using a nasal cannula (2 to 4 L/min).</li>
	<li>Place a central venous or pulmonary artery catheter using local anesthesia (subcutaneous 1% lidocaine) under sterile conditions through the right or left internal jugular vein with ultrasound guidance based on appropriate clinical indications.</li>
	<li>Induce anesthesia using intravenous fentanyl (5 mcg/kg), propofol (1 to 2 mg/kg), and rocuronium (0.1 mg/kg). Maintain anesthesia using inhaled isoflurane (end-tidal concentration of 1%) in an air-oxygen mixture, fentanyl (1 to 2 &#181;g/kg/h), and rocuronium (0.05 mg/kg) titrated to effect using neuromuscular monitoring.</li>
	<li>Suction the stomach using an oral-gastric tube.</li>
	<li>Place ultrasound jelly in the patient&#8217;s hypopharynx. Lift the jaw anteriorly and advance a TEE probe into the esophagus with gentle pressure to overcome resistance of the hypopharygeus muscle.</li>
</ol>
2. Transesophageal Echocardiography
<ol>
	<li>Perform a comprehensive TEE examination following American Society of Echocardiography/Society of Cardiovascular Anesthesiologists guidelines42 in each patient.</li>
	<li>Place a pulse-wave Doppler sample volume between the tips of the mitral leaflets to record trans-mitral blood flow velocity in the mid-esophageal four-chamber TEE imaging plane (Figure 1).</li>
	<li>Identify the early LV filling and atrial systole blood flow waveforms of trans-mitral blood flow velocity, and measure their corresponding peak velocities and velocity-time integrals (VTIE and VTIA, respectively) using the echocardiography equipment&#8217;s integrated software package (Figure 1).</li>
	<li>Calculate the atrial filling fraction (&#946;) as the ratio of atrial to total LV filling: 
	<img alt="Equation 1" src="/files/ftp_upload/58374/58374eq1.jpg" /></li>
	<li>Measure the maximum diameter of the LV outflow tract immediately below the aortic valve in the mid-esophageal aortic valve long axis TEE view during mid-systole (Figure 2A).</li>
	<li>Calculate the area of the LV outflow tract assuming circular geometry as the product of &#960;/4 and the square of the diameter (see step 2.5 above).</li>
	<li>Obtain a deep transgastric long axis TEE view, and place a pulse-wave Doppler sample volume in the distal LV outflow tract to record a blood flow velocity envelope (Figure 2B) at the same level where the diameter was measured (see step 2.5 above); integrate the area of this waveform using the echocardiography equipment&#8217;s software package to obtain VTI.</li>
	<li>Multiply the resulting velocity-time integral (VTI) of the LV outflow track blood flow velocity waveform (Figure 2B) by the area of the outflow track (see step 2.6) to obtain stroke volume (SV).</li>
	<li>Record video clips of the mid-esophageal bicommissural and LV long axis TEE imaging planes, respectively42. Be sure to include several cardiac cycles in each recording.</li>
	<li>Visually inspect slow-motion images of the video clips (see step 2.9 above) after the ECG T-wave to choose the maximum opening of the mitral valve leaflets.</li>
	<li>Measure the distance between the mitral leaflets (Figures 3A and 3B) using the echocardiography equipment&#8217;s &#8220;caliper&#8221; function.</li>
	<li>Calculate the mitral valve diameter (D) as the average of the major (transcommissural anterior-lateral-posterior-medial) and minor (anterior-posterior) lengths.</li>
	<li>Calculate VFT using the formula: 
	<img alt="Equation 2" src="/files/ftp_upload/58374/58374eq2.jpg" /></li>
	<li>Perform all quantitative echocardiographic measurements in triplicate at end-expiration.</li>
</ol>
3. Experimental Design
<ol>
	<li>Determine VFT, indices of LV diastolic function, and hemodynamics during steady-state conditions 30 minutes before and 15, 30, and 60 minutes after cardiopulmonary bypass (CPB) in 10 patients with normal preoperative LV ejection fraction under coronary artery surgery to test the hypothesis that CPB transiently decreases VFT39.</li>
	<li>Test the hypothesis that LV pressure-overload hypertrophy produced by aortic valve stenosis reduces VFT by examining (in one group of 8 patients undergoing aortic valve replacement) for severe aortic stenosis and comparing observations to another group of 8 patients with normal LV wall thickness undergoing coronary artery surgery40. Measure VFT, LV diastolic function, hemodynamics, and end-diastolic posterior wall thickness during steady-state conditions 30 minutes before CPB.</li>
	<li>Test the hypothesis that abnormal diastolic blood flow entering the LV affects trans-mitral LV filling efficiency in 8 patients with aortic valve stenosis and moderate aortic insufficiency versus 8 patients with aortic stenosis who do not have regurgitant valves38. Measure VFT and other parameters as described above (step 3.2).</li>
	<li>Test the hypothesis that advanced age is associated with a reduction in LV filling efficiency quantified using VFT in 7 octogenarians (82 &#177; 2 years) compared to 7 younger patients (55 &#177; 6 years)41 undergoing coronary artery surgery. Ensure that both groups have normal preoperative LV ejection fraction. Measure VFT and other parameters as described above (step 3.2).</li>
</ol>
4. Statistics
<ol>
	<li>Present the data as mean &#177; standard deviation.</li>
	<li>Evaluate data using analysis of variance (ANOVA) followed by Bonferroni&#8217;s modification of Student&#8217;s t-test.</li>
	<li>Use linear regression analysis to determine the relationships between VFT and end-diastolic posterior wall thickness and between VFT and age.</li>
	<li>Reject the null hypothesis when p &#60; 0.05.</li>
</ol>

The authors have no competing financial interests or other conflicts of interest pursuant to this work.

The current results illustrate that VFT can be reliably measured during cardiac surgery using the TEE techniques described here. Previous descriptions of VFT used transthoracic echocardiography in conscious subjects, but this approach cannot be utilized when the chest is open. We used intraoperative TEE to determine VFT in the anesthetized patients undergoing cardiac surgery during which changes in LV filling dynamics are often encountered as a result of ischemia-reperfusion injury or surgical interventions. Our findings...

Fluid mechanics is a critical yet often underappreciated determinant of left ventricular (LV) filling. A three-dimensional rotational body of fluid, known as a vortex ring, is generated whenever a fluid traverses an orifice1,2,3. This vortex ring improves the efficiency of fluid transport compared with a continuous linear jet4. Movement of blood through the mitral valve during early LV filling causes a vortex ring to form5,6,7,8 and facilitates its propagation into the chamber by preserving fluid momentum and kinetic energy9. These actions enhance LV filling efficiency4,10,11,12,13. The ring not only inhibits blood flow stasis in the LV apex14,15,16,17 but also directs flow preferentially beneath the anterior mitral leaflet7,18, effects that decrease the risk of apical thrombus formation and facilitate filling of the LV outflow track19, respectively. Contrast echocardiography17, Doppler vector flow mapping6,20,21, magnetic resonance imaging7, and particle imaging velocimetry9,22,23,24 have been used to demonstrate the appearance and behavior of trans-mitral vortex rings under normal and pathological conditions. The left atrial-LV pressure gradient, the degree of diastolic mitral annular excursion, the minimum LV pressure achieved during diastole, and the rate and extent of LV relaxation are the four major determinants of the duration, size, flow intensity, and position of the trans-mitral ring2,12,25,26,27,28,29.
Vortex ring development is most often quantified with a dimensionless parameter (vortex formation time; VFT) based on fluid ejection from a rigid tube3, where VFT is defined as the product of the time-averaged fluid velocity and the duration of ejection divided by the orifice diameter. The optimal size of a vortex ring is achieved when VFT is 4 in vitro because trailing jets and energetic limitations prevent it from attaining a larger size3,4. Mitral valve VFT has been approximated clinically using transthoracic echocardiography8,30,31. Based on analysis of trans-mitral blood flow velocity and mitral valve diameter (D), it can be easily shown8 that VFT = 4 &#215; (1-&#946;) &#215; EF &#215;&#945;3, where &#946; = atrial filling fraction, EF = LV ejection fraction, and &#945; = EDV1/3/D, where EDV = end-diastolic volume. Ejection fraction is the ratio of stroke volume (SV) and EDV, allowing this equation to be simplified to VFT = 4 &#215; (1-&#946;) &#215; SV/(&#960;D3). Because VFT is dimensionless (volume/volume), this index allows direct comparison between patients of varying size without adjustment for weight or body surface area8. Optimal VFT ranges between 3.3 and 5.5 in healthy subjects8, and results are consistent with those obtained in fluid dynamics models3,32. VFT was shown to be &#8804; 2.0 in patients with depressed LV systolic function, findings that are also supported by theoretical predictions8. Reductions in VFT independently predicted morbidity and mortality in patients with heart failure30. Elevated LV afterload33, Alzheimer&#39;s disease34, abnormal diastolic function19, and replacement of the native mitral valve with a prosthesis35 have also been shown to decrease VFT. Measurement of VFT may also be useful to identify blood flow stasis or thrombosis in patients with acute myocardial infarction36,37.
Our group is interested in factors that affect LV filling efficiency during cardiac surgery38,39,40,41. We use standard two-dimensional and Doppler transesophageal echocardiography (TEE) to noninvasively derive the variables required to calculate VFT. In this report, we describe this methodology in detail and review our findings to date.

<table><tbody><tr><td>Echocardiography Machine</td><td>Philips Ultrasound, Bothall, WA</td><td>iE33</td><td></td></tr><tr><td>Transesophageal Echocardiography Probe</td><td>Philips Ultrasound, Bothall, WA</td><td>X7-2t</td><td></td></tr><tr><td>Statistical Software</td><td>AnalystSoft, Walnut, CA</td><td>StatPlus:mac Pro</td><td></td></tr></tbody></table>

noninvasive determination of vortex formation time using transesophageal echocardiography during cardiac surgery

Trans-mitral blood flow produces a three-dimensional rotational body of fluid, known as a vortex ring, that enhances the efficiency of left ventricular (LV) filling compared with a continuous linear jet. Vortex ring development is most often quantified with vortex formation time (VFT), a dimensionless parameter based on fluid ejection from a rigid tube. Our group is interested in factors that affect LV filling efficiency during cardiac surgery. In this report, we describe how to use standard two-dimensional (2D) and Doppler transesophageal echocardiography (TEE) to noninvasively derive the variables needed to calculate VFT. We calculate atrial filling fraction (&#946;) from velocity-time integrals of trans-mitral early LV filling and atrial systole blood flow velocity waveforms measured in the mid-esophageal four-chamber TEE view. Stroke volume (SV) is calculated as the product of the diameter of the LV outflow track measured in the mid-esophageal long axis TEE view and the velocity-time integral of blood flow through the outflow track determined in the deep transgastric view using pulse-wave Doppler. Finally, mitral valve diameter (D) is determined as the average of major and minor axis lengths measured in orthogonal mid-esophageal bicommissural and long axis imaging planes, respectively. VFT is then calculated as 4 &#215; (1-&#946;) &#215; SV/(&#960;D3). We have used this technique to analyze VFT in several groups of patients with differing cardiac abnormalities. We discuss our application of this technique and its potential limitations and also review our results to date. Noninvasive measurement of VFT using TEE is straightforward in anesthetized patients undergoing cardiac surgery. The technique may allow cardiac anesthesiologists and surgeons to assess the impact of pathological conditions and surgical interventions on LV filling efficiency in real time.

The current technique allowed us to reliably measure VFT during cardiac surgery under a variety of clinical conditions by obtaining each determinant from blood flow and dimensional recordings in standard TEE imaging planes. A pulse-wave Doppler sample volume was placed at the tips of the mitral leaflets in the mid-esophageal four-chamber view to obtain the trans-mitral blood flow velocity profile necessary to calculate atrial filling fraction (&#946;; Figure 1</strong...

Watch this Scientific Journal Video about Noninvasive Determination of Vortex Formation Time Using Transesophageal Echocardiography During Cardiac Surgery at JoVE.com

Noninvasive Determination of Vortex Formation Time Using Transesophageal Echocardiography During Cardiac Surgery

We describe a protocol to measure vortex formation time, an index of left ventricular filling efficiency, using standard transesophageal echocardiography techniques in patients undergoing cardiac surgery. We apply this technique to analyze vortex formation time in several groups of patients with differing cardiac pathologies.

Trans-mitral blood flow produces a three-dimensional rotational body of fluid, known as a vortex ring, that enhances the efficiency of left ventricular ...

noninvasive-determination-vortex-formation-time-using-transesophageal

Research

JoVE Journal

Medicine

7.9K Views.  Clement J. Zablocki Veterans Affairs Medical Center. Deze methode kan helpen bij het beantwoorden van belangrijke vragen over linker ventriculaire vulefficiëntie tijdens een hartoperatie. Het belangrijkste voordeel van deze techniek is dat de vortexvormingstijd kan worden berekend tijdens een hartoperatie met behulp van conventionele trans oesofageale echocardiografietechnieken. Als u een uitgebreid trans oesofageale echocardiografieonderzoek of TEE wilt uitvoeren, plaatst u de sonde voorzichtig in de slokdarm van de patiënt door de kaak van ...

Video: Noninvasive Determination of Vortex Formation Time Using Transesophageal Echocardiography During Cardiac Surgery

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 ...

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 ...

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 ...

Bioengineering

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 ...

Echocardiographic Evaluation of Atrial Communications before Transcatheter Closure

Transthoracic (TTE) and transesophageal echocardiography (TEE) is the standard imaging method for atrial septal defect (ASD) and patent foramen ovale (PFO) detection, for patient selection for transcatheter ASD/PFO closure,&#160;for intraoperative guidance and for long-term follow-up. The size, shape, location and the number of the atrial communications schould be determined. The accuracy of PFO detection can be improved by using agitated saline together with maneuvers to transiently increase the right atrial (RA) pressure. The appearance of microbubbles in the left atrium (LA) within 3 cardiac cycles after opacification of the RA is considered positive for the presence of an intracardiac shunt. Three dimensional TEE identifies further septal fenestrations and describes the dynamic morphology of ASD/PFO and atrial septal aneurysm. Follow-up evaluations with TTE is recommended at 1, 6, and 12 months after the procedure, with a subsequent evaluation every year. Previous studies showed an increased incidence of atrial arrhythmias early after device closure. Speckle tracking analysis may help to understand functional left atrial remodeling following percutaneous closure and its impact on atrial arrhythmias.

Transthoracic (TTE) and transesophageal (TEE) echocardiography represent the basic imaging tools for interatrial septum examination. Three dimensional (3D) TEE provides incremental information in the assessment of the interatrial septum. Further advanced echocardiography techniques using speckle tracking echocardiography are applied for sensitive volumetric and functional assessment of the heart chambers.&#160;

Transthoracic (TTE) and transesophageal echocardiography (TEE) is the standard imaging method for atrial septal defect (ASD) and patent foramen ovale ...

Transthoracic Echocardiography to Assess Post-Resuscitation Left Ventricular Dysfunction After Acute Myocardial Infarction and Cardiac Arrest in Pigs

One of the main causes of out-of-hospital cardiac arrest is acute myocardial infarction (AMI). After successful resuscitation from cardiac arrest, approximately 70% of patients die before hospital discharge due to post-resuscitation myocardial and cerebral dysfunction. In experimental models, myocardial dysfunction after cardiac arrest, characterized by an impairment in both left ventricular (LV) systolic and diastolic function, has been described as reversible but very little data are available in cardiac arrest models associated with AMI in pigs. Transthoracic echocardiography is the first-line diagnostic test for the assessment of myocardial dysfunction, structural changes and/or AMI extension. In this pig model of ischemic cardiac arrest, echocardiography was done at baseline and 2-4 and 96 hours after resuscitation. In the acute phase, the examinations are done in anesthetized, mechanically ventilated pigs (weight 39.8 &#177; 0.6 kg) and ECG is recorded continuously. Mono- and bi-dimensional, Doppler and tissue Doppler recordings are acquired. Aortic and left atrium diameter, end-systolic and end-diastolic left ventricular wall thicknesses, end-diastolic and end-systolic diameters and shortening fraction (SF) are measured. Apical 2-, 3-, 4-, and 5-chamber views are acquired, LV volumes and ejection fraction are calculated. Segmental wall motion analysis is done to detect the localization and estimate the extent of myocardial infarction. Pulsed Wave Doppler echocardiography is used to record trans-mitral flow velocities from a 4-apical chamber view and trans-aortic flow from a 5-chamber view to calculate LV cardiac output (CO) and stroke volume (SV). Tissue Doppler Imaging (TDI) of LV lateral and septal mitral anulus is recorded (TDI septal and lateral s&#39;, e&#39;, a&#39; velocities). All the recordings and measurements are done according to the recommendations of the American and European Societies of Echocardiography Guidelines.

Transthoracic echocardiography is the first-line diagnostic test for post-resuscitation left ventricular dysfunction and structural changes in a pig model of cardiac arrest.

One of the main causes of out-of-hospital cardiac arrest is acute myocardial infarction (AMI). After successful resuscitation from cardiac arrest, ...

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, ...

Advancements in Echocardiography-Derived Blood Speckle Imaging Technology

Assessing Intracardiac Vortices with High Frame-Rate Echocardiography-Derived Blood Speckle Imaging in Newborns

The left ventricle (LV) has a unique pattern of hemodynamic filling. During diastole, a rotational body or ring of fluid known as a vortex is formed due to the chiral geometry of the heart. A vortex is reported to have a role in conserving the kinetic energy of blood flow entering into the LV. Recent studies have shown that LV vortices may have prognostic value in describing diastolic function at rest in neonatal, pediatric, and adult populations, and may help with earlier subclinical intervention. However, the visualization and characterization of the vortex remain minimally explored. A number of imaging modalities have been utilized for visualizing and describing intracardiac blood flow patterns and vortex rings. In this article, a technique known as blood speckle imaging (BSI) is of particular interest. BSI is derived from high-frame rate color Doppler echocardiography and provides several advantages over other modalities. Namely, BSI is an inexpensive and noninvasive bedside tool that does not rely on contrast agents or extensive mathematical assumptions. This work presents a detailed step-by-step application of the BSI methodology used in our laboratory. The clinical utility of BSI is still in its early stages, but has shown promise within the pediatric and neonatal populations for describing diastolic function in volume-overloaded hearts. A secondary aim of this study is thus to discuss recent and future clinical work with this imaging technology.

Author Spotlight: Advancing Neonatal Cardiac Diagnostics with Echocardiography-Derived Blood Speckle Imaging 

The present protocol uses echocardiography-derived blood speckle imaging technology to visualize intracardiac hemodynamics in newborns. The clinical utility of this technology is explored, the rotational body of fluid within the left ventricle (known as a vortex) is accessed, and its significance in understanding diastology is determined.

The left ventricle (LV) has a unique pattern of hemodynamic filling. During diastole, a rotational body or ring of fluid known as a vortex is formed due ...

Point-of-Care Ultrasound for Peripheral Veno-Arterial Extracorporeal Membrane Oxygenation Without Left Ventricular Venting

Over the past several decades, veno-arterial extracorporeal membrane oxygenation (V-A ECMO) has become a critical tool in the management of patients with severe cardiogenic shock and cardiopulmonary failure. Due to the inherent instability of these patients, their transport away from intensive care units is fraught with risk. As a result, bedside diagnostic tools are essential for their daily care. One such tool is point-of-care ultrasound (POCUS) of the heart, which can non-invasively assess several parameters: left ventricular (LV) performance (size, systolic function, stroke volume, aortic valve opening), right ventricular (RV) performance (size, systolic function), and the presence of intracardiac thrombus. Additionally, POCUS can assist in evaluating readiness for V-A ECMO weaning and eventual decannulation. Despite its potential, the use of POCUS in the context of V-A ECMO remains inconsistent due to variability in provider training. This study aims to address this gap by detailing POCUS image acquisition in V-A ECMO, particularly in the absence of LV venting. It covers key aspects such as patient positioning, transducer selection, probe placement, acquisition sequence, and image optimization.

This protocol outlines the use of point-of-care ultrasound (POCUS) to monitor patients on peripheral veno-arterial extracorporeal membrane oxygenation (V-A ECMO) without left ventricular venting. It evaluates left ventricular distension, intracardiac or aortic root thrombus, and identifies useful cardiac POCUS parameters for weaning from V-A ECMO.

Over the past several decades, veno-arterial extracorporeal membrane oxygenation (V-A ECMO) has become a critical tool in the management of patients with ...

Noninvasive Determination of Vortex Formation Time Using Transesophageal Echocardiography During Cardiac Surgery

Samenvatting

Meer video's verkennen