Figure 5.

Electrophysiological properties in HEK293 cells of mutant hNa_v1.5 channels associated with BrS. (A) Inactivation time constants τ_h (ms) as function of voltage. K126E channels inactivated more slowly at −50 mV (^**), R27H inactivated more slowly from −50 to −25 mV (^*), when compared to hNa_v1.5. R18Q, G35S, and V95I channels were indistinguishable from hNa_v1.5 (data not shown). (B) Steady-state activation and steady-state inactivation curves. Mid-activation potentials (V_m) were significantly shifted towards depolarized potentials in both R27H and K126E. Mid-inactivation potential V_h was shifted only in K126E. The figure was drawn using the mean of 4 representative measurements for each. V_m and V_h of the other mutant channels, R18Q, G35S and V95I, were indistinguishable from the respective hNa_v1.5 values. For data and statistics see Table 2.