Fig. 1

Schematic diagram of calculating ICA. Panel 1: CAMM plot showing the strain rate propagation throughout systole obtained by three-chamber STE-analysis. Panel 2: Zoom on the CAMM plot illustrating the pixels and the color scale used to decode the strain rate values. Panel 3: Extraction of strain rate values from the CAMM plot followed by pairwise subtraction of strain rate values of the opposing corresponding pixels [top rows (T) minus bottom rows (B)] for each column (C), creating a new table containing the strain rate differences (middle table). Panel 4: Density plot of the strain rate differences between the two opposing walls and the corresponding standard deviation (SD) of those differences. This value is referred to as ICA. In this example, ICA in the three-chamber view is 0.76 s^− 1. CAMM, curved anatomical M-mode; ICA, Index of Contractile Asymmetry; SrL, strain rate; STE, speckle tracking echocardiography