ABSTRACT: BACKGROUND:Two-dimensional speckle-tracking echocardiography (2D-STE) enables objective assessment of left atrial (LA) deformation through the analysis of myocardial strain, which can be measured by different speckle-tracking software. The aim of this study was to compare the consistency of 3 different commercially available software, which include vendor-specific software for measuring left ventricle (VSSLV), vendor-independent software packages for measuring LV strain (VISLV) and vendor-independent software packages for measuring LA strain (VISLA). METHODS:Sixty-four subjects (mean age: 44?±?16?years, 50% males) underwent conventional echocardiograms using a GE Vivid 9 (GE Ultrasound, Horten, Norway) cardiac ultrasound system. Standard apical 4 and 2 chamber views of the left atrium were obtained in each subject with a frame-rate range of 40-71 frames/s. LA strain during the contraction phase (Sct), conduit phase (Scd), reservoir phase (Sr?=?Sct?+?Scd) were analyzed by 2 independent observers and 3 different software. RESULTS:Sct, Scd, Sr were, respectively, -?11.26?±?2.45%, -?16.77?±?7.06%, and 28.03?±?7.58% with VSSLV, -?14.77?±?3.59%, -?23.17?±?10.33%, and 38.23?±?10.99% with VISLV, and?-?14.80?±?3.88%, -?23.94?±?10.48%, and 38.73?±?11.56% when VISLA was used. A comparison of strain measurements between VSSLV and VIS (VISLV and VISLA) showed VIS had significantly smaller mean differences and narrower limits of agreement. Similar results were observed in the coefficient of variation (CV) for measurements between VSSLV and VIS (VISLV and VISLA). Comparison of the intra-class correlation coefficients (ICCs) indicated that measurement reliability was weaker with VSSLV (ICC??0.9). For intra-observer ICCs, VISLA?>?VSSLV?=?VISLV. For inter-observer ICCs, VSSLV?>?VISLA?>?VISLV. CONCLUSIONS:Software measurement results of LA strain vary considerably. We recommended not measuring LA strain across vendor platforms.