Left ventricle
For two-dimensional global longitudinal peak strain, three consecutive cardiac cycles in the apical two, three and four-chamber views were acquired for analysis with frame rates between 50 to 80 frames/second using velocity vector imaging. The automatized software tracked the contour of the endocardium and automatically divided the left ventricle into six segments. Deformation was assessed frame by frame. Left ventricular global longitudinal strain represents the apical to base deformation, and it is expressed with negative values because the LV shortens during systole. More negative values are associated with a better longitudinal performance. Decreased LV-GS was defined as values ≥-20% as previously described (Figure 2A) (13).