Fig. 1.

Steady-state action potential (AP) and ionic currents under control conditions (solid line) and atrial fibrillation-related electrical remodeling (AFER) conditions (dashed line) at cycle length (CL) = 1,000 ms using a human atrial AP model proposed by Maleckar et al. (42) based on the original Nygren et al. model (49) (referred to as the MGGT model; left) and a second AP model developed by Courtemanche et al. (17) (referred to as the CRN model; right) human atrial AP models. I_NaK, Na⁺/K⁺ pump current; I_K1, inward rectifier potassium current; I_Na, Na⁺ current; I_Kur, ultrarapid delayed potassium current; I_to, transient outward current; I_CaL, L-type calcium current; I_NaCa, Na⁺/Ca²⁺ exchanger current.