FIGURE 2.

Comparison of ORd and BPS2020 behavior for [Ca²⁺]_o variations. (A) Simulated action potential (AP) for the original ORd and the BPS2020 models (left and right panels, respectively) for three different [Ca²⁺]_o. In control conditions ([Ca²⁺]_o = 1.8 mM, solid lines), results with the two models are quite similar. However, when [Ca²⁺]_o increases ([Ca²⁺]_o = 2.7 mM, dashed lines) or decreases ([Ca²⁺]_o = 0.9 mM, dotted lines), they behave in two opposite ways. Only BPS2020 reproduces the inverse APD-[Ca²⁺]_o relationship observed experimentally. (B) APD-[Ca²⁺]_o relationship for ORd (light blue) vs. BPS2020 (dark blue). (C) Changes observed in the APD-[Ca²⁺]_o relationship of BPS2020 when restoring I_CaL (dotted line) or J_rel (dashed line) to the original ORd formulations.