Figure 3.

Time-course of final repolarization (top), I_Na availability (middle), and S1S2 CV restitution curves (bottom) in the minimal LR-I model, for (A) V_rest corresponding to [K⁺]_o = 5.4 mmol/L and (B) V_rest corresponding to [K⁺]_o = 2.0 mmol/L. Simulation results are shown for two repolarization time constants (30 and 10 ms). Solid lines correspond to the nominal I_Na formulation and dashed lines were obtained by disabling the j gate of I_Na, simulating accelerated recovery from inactivation. Time is measured from repolarization to −60 mV, defining the beginning of the DI.