Fig. 1
3D models of ventricular tissue. a Schematic diagram of the electrical and mechanical components coupled by the Ca2+ transient. The electrical component represents the ionic currents and pumps based on the ionic model of Tusscher et al. [36]. The following are shown: the fast inward Na+ current (INa), background Na+ current (INa,b), L-type inward Ca2+ current (ICa,L), background Ca2+ current (ICa,b), rapid delayed rectifier K+ current (IKr), slow delayed rectifier K+ current (IKs), inward rectifier K1 current (IK1), Na+–Ca2+ exchanger current (INa,Ca), sarcoplasmic Ca2+ pump current (Ip,Ca), Na+–K+ exchange current (INa,K), transient outward K+ current (Ito), K+ pump current (Ip,K), Ca2+ release current from the JSR (Irel), Ca2+ leak current from the JSR (Irel), and Ca2+ uptake current into the NSR (Iup). The mechanical component represents the electromechanical model [41] coupled with the circulatory system [28]. The following are shown: the RV pressure (PRV), RV volume (VRV), LV pressure (PLV), LV volume (VLV), pulmonary artery resistance (RPA), pulmonary artery compliance (RPV), pulmonary vein resistance (RPV), pulmonary vein compliance (CPV), mitral valve resistance (RMI), left atrium compliance (CLA), systemic vein resistance (RSV), systemic vein compliance (CSV), tricuspid valve resistance (RTR), right atrium compliance (CRA), pulmonary valve resistance (RPU), non-permissive and permissive conformations of regulatory proteins (NXB and PXB, respectively), pre-rotated state bounding with the head extended (XBPreR), and post-rotated state illustrating the isomerization for strain inducing the neck region (XBPostR). b Three heterogeneous models with different thicknesses of the heart-wall layers (epicardium, mid-myocardium, and endocardium)