Comparison of line plots and colour plots of the same longitudinal velocity data (a) Regional longitudinal mid-ventricular velocity-time curves averaged over all volunteers. (b) The corresponding 2D colour plot showing regional variation. The positions of end systole, the beginning of diastasis and the beginning of atrial systole are marked by vertical lines. The horizontal lines split the colour plot into 6 regions to make comparison with the velocity-time curves easier. The red dotted circles highlight various regional features of motion and allow comparison of the velocity-time curves and 2D colour plot.