Figure 1.
Simulation of drug-induced LQTS. Cardiac ventricular action potentials generated by using the Luo—Rudy cellular model (28) representing control, drug-free conditions (0% block) and conditions in which the same drug concentration blocks 50% and 100% of available IKr channels. Modest action potential prolongation caused by 50% channel block can be antiarrhythmic, but extreme prolongation caused by block of all available channels induces secondary depolarizing activity, which can be proarrhythmic.