Figure 5.

Modeling the effect of the R12Q variant at the heterozygous state. A, The Kv4.3 current density is increased by an averaged factor of 2.5 at +60 mV and by a minimal factor of 1.5 when considering only the lower limit for the heterozygous R12Q condition. B, Action potentials of the subendocardial (endo), midmyocardial (mid), and subepicardial (epi), corresponding, respectively, to cells 15, 80, and 150 in a 165‐cell fiber (thin, dashed, and thick lines, respectively) in control condition (black) and in presence of a 1.9‐fold (red) or a 2.5‐fold (blue) increase in I _to,f. Shown is the 10th beat at 1 Hz. C, Corresponding right ventricular outflow tract wedge pseudo‐ECG, in arbitrary units (a.u.). D, Heat map of voltage in space and time (vertical and horizontal axes, respectively) in control condition and in the presence of a 1.9‐ and 2.5‐fold increase in I _to,f. Stimulation (stim) was given on cell 1. In all conditions, there was zero I _to in subendocardium, and 85% as much I _to in midmyocardium as in subepicardium.