Figure 2.

Propafenone interactions with sodium channels. (Ai) Simulated (solid lines) and experimental (points) use-dependent block of sodium channels by propafenone (PROPAF) elicited using a series of 8 pulses from −90 mV to 0 mV at 3 Hz for three different test concentrations. (Aii) Steady state block of sodium channels using pulses from −90 mV to 0 mV at 3 Hz until a steady state was achieved. Experimental data are taken from Harmer et al. (2008), where the steady state block IC₅₀ value is given as 1.4 μM. (B) Simulated and (C) experimentally-measured PROPAF-induced reduction in maximum upstroke velocity (${\stackrel{°}{V}}_{max}$) upon application of 0.3 and 1.5 μM PROPAF at a cycle length (CL) of (i) 500 ms and (ii) 300 ms. All ${\stackrel{°}{V}}_{max}$ reductions are relative to the control (C) value at a CL of 500 ms. Experimental data, recorded from canine atrial myocytes, are taken from Burashnikov et al. (2012).