Evaluation Of Left Ventricular Systolic Function Using Speckle Tracking Echocardiography:a Comparison Between Three-Dimensional And Two-Dimensional Approaches

Objective:To assess left ventricular global longitudinal strains(GLS), global circumferential strains(GCS), global radial strains(GRS) and global area strains(GAS) by using two dimensional speckle tracking(2DT) and three dimensional speckle tracking(3DT), to investigate the feasibility of3DT for assessment of left ventricular systolic function.Methods:Fifty-one healthy volunteers were consecutively enrolled, five subjects were excluded from this study because of poor image quality for analysis. Finally, forty-six subjects were evaluated with three dimensional speckle tracking(3DT), Global strain parameters including Global longitudinal strain(GLS), Global circumferential strain (GCS), Global radial strain(GRS) and Global area strain (GAS), as well as left ventricular volumes including end-diastole dimension volume (EDV), end systole dimension volume (ESV) and left ventricular ejection fraction(LVEF) were examined and then compared the data with those measured by two dimensional speckle tracking.Results:①Out of51subjects prospectively enrolled in this study,5patients were excluded due to inadequate myocardial tracking. Among the remaining46examined subjects (29male, mean age47.3±15.5years), The mean2D-LVEF was slightly but significantly higher than the mean3D-LVEF (65.6±8.9vs60.7±8.3%, P<0.05). The mean EDV was higher in2D than in the3D mode (105.8±19.9vs97.4±17.2mL, P<0.05), whereas ESV was similar in both modes (39.5±14.5vs38.1±13.1mL, P>0.05).②Average acquisition and analysis time was significantly shorter for3DT than2DT (all P<0.05).③GCS values were slightly higher in3DT than in2DT (-29.1±8.8vs.-25.2±8.5%, P<0.05) and GLS values were lower in3DT than in2DT (-19.2±5.9vs.-22.5±6.4%, P<0.05). GRS values were similar between3DT and2DT (30.9±10.0vs.29.7±9.2%, P>0.05).④Both3DT and2DT longitudinal strains, Circumferential strains values were smallest in the basal region and increased in the mid and apex regions. In contrast, radial strains were smaller in the apical region compared with the basal and mid regions (all P<0.05).⑤Linear regression analysis showed that GLS, GCS, GRS and GAS in3DT had a significant correlation with the LVEF(r1=0.86, P1<0.05; r2=0.81,P2<0.05; r3=-0.75,P3<0.05;r4=0.64, P4<0.05; respectively). Among all3DT strain parameters, GAS had closest correlation with left ventricular ejection fraction.⑥All Intra-and inter-observer variability of GLS, GCS and GRS using2DT and3DT were smaller than15%. No significant difference in the intra-observer and inter-observer coefficient variation between3DT and2DT were observed.Conclusion:①3DT allows accurate and faster analysis of deformation when compared with2DT and might represent a viable alternative in the evaluation of global LV function. However, further improvements are needed to firmly establish this technology as superior to2DT in the assessment of deformation.②Area strain is a valuable index for evaluation of left ventricular systolic function. Graph9, Table6, References23...