Fig. 4.
A–C: transmembrane voltage (Vm; A), free intracellular Ca2+ concentration ([Ca2+]i; B), and total Ca2+ bound to troponin C ([Ca2+]troponin; C) plotted over time for simulations with our electromechanical right atrial (RA) myocyte model with only chronic atrial fibrillation (cAF)-induced ionic remodeling incorporated (blue lines) and the uncoupled cAF RA ionic model (red lines). The final two beats (of the 74 total beats) isometrically paced at a cycle length (CL) of 400 ms and sarcomere length (SL) of 1.9 µm are shown for each model. D: normalized active force plotted only over time for our electromechanical model.