Figure 1. Testing IC₅₀ of flecainide in the cell model for I_Na, RyR2 and both targets in combination .

Voltage dynamics is shown for each IC₅₀ case, and the voltage and Ca²⁺ transient maxima are binned for each pacing frequency between 0.5 and 3 Hz during the second half of a 2 min simulation time course. A, CASQ2(−/−) myocytes with 3, 4 and 5 μM IC₅₀ effects on both Na⁺ channels and RyRs. B, flecainide interaction with just Na⁺ channels. C, flecainide concentrations acting on only RyRs.