Simulation of the Undiseased Human Cardiac Ventricular Action Potential: Model Formulation and Experimental Validation
Figure 17
IKr deactivation is important for APD restitution at very short DIs.
A) APD restitution in control (solid black), and when the fast and slow deactivation gates (xrfast and xrslow) were reset to the DI = S1 = 1000 ms value at the start of the S2 beat (dashed gray). Bottom) Zoom in to more clearly show the consequence of deactivation resetting at short DIs (section outlined by dashed box above). B) Traces for the AP (top) and IKr (bottom) during the S2 beat at different DIs (indicated by arrows). Spiking in IKr occurred early during the AP at short DI. Spiking was caused by slow deactivation, increasing availability of IKr.