Truong VT, Phan HT, Pham KNP, et al. - Experts conducted a meta-analysis of normal ranges of left ventricular (LV) global longitudinal strain (GLS), global circumferential strain (GCS), global radial strain (GRS), and global area strain (GAS) measurements derived by three-dimensional speckle-tracking echocardiography (3DSTE) and recognized confounding factors that may add to difference in reported measures. A total of 895 articles were discovered. Following abstract and full-text screening, 33 data sets with 2,346 individuals for meta-analysis were involved. Among the studies, the reported normal mean values of GLS, GCS, GRS, and GAS differed from −15.80% to −23.40%, from −15.50% to −39.50%, from 19.81% to 86.61%, and from –27.40% to –50.80%, respectively. Software for strain analysis was constantly related to changes in normal strain values. Thus, across studies, changes in the normal ranges were significantly related to the software utilized for strain analysis, highlighting that this factor should be acknowledged in the elucidation of strain data.