Global area strain is a new and robust parameter to characterize left ventricular systolic function by three-dimensional speckle-tracking echocardiography

Background: Three-dimensional (3D) speckle-tracking echocardiography enables the quantification of left ventricular (LV) myocardial deformation in all 3 directions from a single LV full-volume data set. In addition, 3D tracking has the unique advantage of computing area strain (AS) variations, corresponding to the total myocardial contraction that combines the longitudinal (LS) and circumferential strain (CS) of a particular segment. Aim: We sought to assess the potential value of bi-directional AS in comparison to one-directional strain components to predict LV dysfunction (LVEF≤55%). Methods and results: In 60 consecutive patients (pts, age 58±15, 68% men, LVEF range from 17% to 65%) in sinus rhythm, LV full-volume data sets were acquired using Vivid E9 with 4V probe (GE Healthcare, Horten, NO) and analyzed with 4D strain package (EchoPac BT 11). Global peak values of LS, CS, AS and radial strain (RS) and were analyzable in 58 pts. 3D LVEF was correlated with AS in overall population (r=0.87) and in pts with EF>55% (N=33, r=0.46), more closely than LS (r=0.79 and r=0.41) and comparably with CS (r=0.87 and r=0.43, respectively) (p≤0.02 for all). Conversely, RS showed weaker correlation with 3D LVEF in all pts (r=0.53, p<0.001) and no correlation with 3D LVEF in pts with preserved EF (p=0.93). Results for ROC curve analysis to assess the accuracy of various strain parameters to predict a LVEF ≤55% are displayed in Table 1. AS also showed a good intra- and inter-observer reproducibility (intraclass correlation coefficients 0.98 and 0.96; bias ± limits of agreement 0.6±3.4% and 1.7±4.1%, respectively).Conclusions: Novel AS by 3D speckle-tracking seems robust and superior than global LS to predict global LV systolic dysfunction. However, among all strain components, global CS had the best discriminative power to identify a LVEF≤55%.