LVEF – global 4Ch strain correlation. Correlation plot of absolute strain values vs LV ejection fraction (LVEF) in a CRT population (unpublished data, De Boeck, et al). Absolute strain values are calculated as mean of the end systolic (global) strain values of the septal and lateral wall using 2DSE. LVEF is calculated using the Simpson's rule. Note the good correlation over a broad range of LVEF.