Right atrial longitudinal strain and strain rate determined by 2D speckle tracking echocardiography (2D-STE). The right atrial longitudinal strain and strain rate determined by 2D speckle tracking echocardiography (2D-STE): the right atrial (RA) wall was divided into six segments automatically. Peak right atrial longitudinal strain (RALS) and systolic strain rate (RALSR) were measured in each segment at the mid-RA free wall and interatrial septum, and global values were calculated