Fig. 5

Comparison of hemiglobal strain patterns depending on activation delay and ratio of the delayed compartment. a Schemata of a two-compartment ventricular model. Hemiglobal longitudinal strains on the earlier activated and delayed wall regions (brown and purple double arrows, respectively) can be estimated according to Additional file 1: Appendix C. The simulated strains were calculated over hemiglobal three segments among seven global segments without an apical cap segment, irrespective of boundaries (red triangles) between the earlier activated and delayed compartments (walls colored in yellow and blue, respectively). b Simulated time–strain curves during a cardiac cycle. The brown and purple lines represent hemiglobal strains on an earlier activated and delayed regions, respectively. The superimposed gray areas indicate the ejection period. As an activation delay of ΔT (top to bottom row) and the ratio of the delayed compartment (left to right column) increased, an uncoordinated double-peak shortening was exaggerated at an earlier activated hemiglobal wall (red arrows). When the ratio of the delayed compartment was large enough, a first peak became small (green arrow). c A representative hemiglobal longitudinal strain curve at an earlier activated ventricular wall (white dotted line) in a patient with single ventricle. The blue, red, or purple lines represent regional myocardial strain curves, and bottom green line presents the electrocardiogram