Normal Ranges of Left Atrial Strain and 3D Echocardiographic Volume Measurements in Türkiye

Objective: The clinical importance of left atrial (LA) remodeling and function have been shown in various cardiovascular diseases, such as heart failure and atrial fibrillation. The LA dimension and volume index are the currently recommended parameters for evaluation of LA. Speckle tracking echocardiography makes it possible to evaluate the physio-mechanics of the LA method and threedimensional echocardiography have been shown to provide robust calculations of LA volume. However, there is still a lack of reference values regarding the LA longitudinal strain (LS) and three-dimensional (3D) volumetric measurements in Türkiye. Thus, we sought to investigate and determine normal references for mentioned echocardiographic methodologies by examining healthy individuals. Methods: The echocardiographic data of one-hundred and forty-six volunteers without known cardiovascular pathologies were analyzed. 3D volume measurements and LA longitidinal strain in the reservoir, conduit, and contraction phase were investigated. Trigger points were placed on the R-waves on the electrocrocardiogram, as suggested by recent recommendations. Results: Our study revealed a normal reference range for LA reservoir LS [40% (95% confidence interval (CI): 38-43%)], LA conduit LS [24% (95% CI: 22-26%)], LA contraction phase LS [16% (95% CI: 13-18%)] and for 3D maximal LA volume of 28 mL/m2 (95% CI: 25-32). Conclusion: We have provided normal reference ranges for phasic LA LS and 3D volume measurements. Having normal reference ranges for Turkish population carries importance as regional difference can occur.