Real-time evaluation of longitudinal peak systolic strain (speckle tracking measurement) in left and right ventricles of athletes

<p>Abstract</p> <p>Background</p> <p>Strain, and particularly Longitudinal Peak Systolic Strain (LPSS), plays a role in investigating the segmental and overall contractility of the heart which is a particularly interesting feature in athletes in whom regular training determines several morphological and functional modifications in both the ventricles, that normally work at different loads. Speckle tracking techniques assess the LPSS of LV and RV from B-mode imaging in real time, with uniform accuracy in all segments, and can verify the possible dissimilar segmental contributions of the two chambers to overall myocardial contraction. The aim of the study is to quantify the LPSS in real time in both the ventricles in order to estimate any possible different deformation properties in them during a systolic period.</p> <p>Methods</p> <p>32 subjects (20 athletes and 18 controls) were submitted to a standard echocardiographic examination at rest and after a Hand Grip (HG) stress. From a four-chamber-view image, the LPSS parameter was measured with Speckle Tracking analysis in the basal and medium-apical segments of the two ventricles, at rest and after HG.</p> <p>Results</p> <p>In both athletes and controls, LPSS values were significantly higher in the RV of athletes (RV LPSS ^{medium-apical}-23.87 ± 4.94; ^{basalfreewall}-25.04 ± 4.12 at rest) and controls (RV LPSS^{medium-apical}-25.21 ± 4.97; ^{basalfreewall}-28.69 ± 4.62 at rest) than in the LV of both (athletes LV LPSS ^{medium-apical}-18.14 ± 4.16; ^{basallateralwall}-16.05 ± 12.32; controls ^{medium-apical}-18.81 ± 2.64; ^{basallateralwall}-19.74 ± 3.84) With the HG test a significant enhancement of the LPSS(with P < .05) in the medium-apical segments of LV and RV was evident, but only in athletes; there was no modification of the standard echo-parameters in either group.</p> <p>Conclusion</p> <p>ST analysis is an easy method for investigating the contractility of the RV through deformation parameters, showing greater involvement of the RV than LV at rest. In athletes only, after isometric stress the two ventricles show particular myocardial deformation properties of the regions around the apex where the curvature of the wall is more marked. The clinical application of this new approach in athletes and normal subjects requires further investigation.</p

A new 2D-based method for myocardial velocity strain and strain rate quantification in a normal adult and paediatric population: assessment of reference values

<p>Abstract</p> <p>Background</p> <p>Recent advances in technology have provided the opportunity for off-line analysis of digital video-clips of two-dimensional (2-D) echocardiographic images.</p> <p>Commercially available software that follows the motion of cardiac structures during cardiac cycle computes both regional and global velocity, strain, and strain rate (SR).</p> <p>The present study aims to evaluate the clinical applicability of the software based on the tracking algorithm feature (studied for cardiology purposes) and to derive the reference values for longitudinal and circumferential strain and SR of the left ventricle in a normal population of children and young adults.</p> <p>Methods</p> <p>45 healthy volunteers (30 adults: 19 male, 11 female, mean age 37 ± 6 years; 15 children: 8 male, 7 female, mean age 8 ± 2 years) underwent transthoracic echocardiographic examination; 2D cine-loops recordings of apical 4-four 4-chamber (4C) and 2-chamber (2C) views and short axis views were stored for off-line analysis.</p> <p>Computer analyses were performed using specific software relying on the algorithm of optical flow analysis, specifically designed to track the endocardial border, installed on a Windows™ based computer workstation. Inter and intra-observer variability was assessed.</p> <p>Results</p> <p>The feasibility of measurements obtained with tissue tracking system was higher in apical view (100% for systolic events; 64% for diastolic events) than in short axis view (70% for systolic events; 52% for diastolic events). Longitudinal systolic velocity decreased from base to apex in all subjects (5.22 ± 1.01 vs. 1.20 ± 0.88; p < 0.0001). Longitudinal strain and SR significantly increased from base to apex in all subjects (-12.95 ± 6.79 vs. -14.87 ± 6.78; p = 0.002; -0.72 ± 0.39 vs. -0.94 ± 0.48, p = 0.0001, respectively). Similarly, circumferential strain and SR increased from base to apex (-21.32 ± 5.15 vs. -27.02 ± 5.88, p = 0.002; -1.51 ± 0.37 vs. -1.95 ± 0.57, p = 0.003, respectively).</p> <p>Values of global systolic SR, both longitudinal and circumferential, were significantly higher in children than in adults (-1.3 ± 0.2, vs. -1.11 ± 0.2, p = 0.006; -1.9 ± 0.6 vs. -1.6 ± 0.5, p = 0.0265, respectively). No significant differences in longitudinal and circumferential systolic velocities were identified for any segment when comparing adults with children.</p> <p>Conclusion</p> <p>This 2D based tissue tracking system used for computation is reliable and applicable in adults and children particularly for systolic events. Measured with this technology, we have established reference values for myocardial velocity, Strain and SR for both young adults and children.</p

Characterization and Quantification of Vortex Flow in the Human Left Ventricle by Contrast Echocardiography Using Vector Particle Image Velocimetry.

The aims of this study were to: 1) assess the feasibility of left ventricular (LV) vortex flow analysis using contrast echocardiography (CE); and 2) characterize and quantify LV vortex flow in normal subjects and patients with LV systolic dysfunction. Vortices that form during LV filling have specific geometry and anatomical locations that are critical determinants of directed blood flow during ejection. Therefore, it is clinically relevant to assess the vortex flow patterns to better understand the LV function. Twenty-five patients (10 normal and 15 patients with abnormal LV systolic function) underwent CE with intravenous contrast agent, Definity (Bristol-Myers Squibb Medical Imaging, Inc., North Billerica, Massachusetts). The velocity vector and vorticity were estimated by particle image velocimetry. Average vortex parameters including vortex depth, transverse position, length, width, and sphericity index were measured. Vortex pulsatility parameters including relative strength, vortex relative strength, and vortex pulsation correlation were also estimated. Vortex depth and vortex length were significantly lower in the abnormal LV function group. Vortex width was greater and sphericity index was lower in the abnormal LV function group. Relative strength, vortex relative strength, and vortex pulsation correlation were significantly lower in the abnormal LV function group. It was feasible to quantify LV vorticity arrangement by CE using particle image velocimetry in normal subjects and those with LV systolic dysfunction, and the vorticity imaging by CE may serve as a novel approach to depict vortex, the principal quantity to assess the flow structure