Fig. 5.
Blocking effects of class Ia, Ib and Ic antiarrhythmic agents on ICaL. Top: Representative original traces of ICaL recorded in the absence and presence of the class I antiarrhythmic agents at indicated concentrations. ICaL was elicited by a train of 300-ms test pulses to 0 mV from the HP of −50 mV at 0.2 Hz, with steady-state currents determined at the 20th pulses. Bottom: Concentration-dependent inhibitory effects of the three class I antiarrhythmic agents on ICaL (n = 7–10). The data were fitted by Eq. (1) with the mean IC50 and Hill coefficient values given in the text.