Speckle-tracking echocardiography
All images were analyzed by a single investigator (S.C.) who was blinded to the participants’ characteristics and exercise performance. For the LA strain, the LA endocardium was manually traced at the end systole stage of LV, and the software automatically tracked the myocardium throughout the cardiac cycle on electrocardiography using R-to-R gating. Figure The LV endocardium was traced at end systole in the 4-, 3-, and 2- apical views; the region of interest was selected with software and was adjusted to accommodate the thickness of the LV myocardium. The LV global longitudinal strain (LVGLS) was measured as the average strain of 17 segments.