The role of Ca2+-channel blockers in the transition from ventricular fibrillation to ventricular tachycardia in an anatomical model of the human ventricles: a simulation study

We have investigated the effect of blocking the Ca²⁺-channel on the transition from fibrillation to tachycardia in simulations in an anatomical model of the human ventricles, using a previously developed model of human ventricular cells where ventricular fibrillation was obtained by the process of spiral wave breakup. We show that blocking the Ca²⁺-current by 75% can convert fibrillation into a periodic regime with a single stable spiral waves, which anchored to an anatomical obstacle. We show that the observed effects were due to a flattening of the restitution curve, which prevented the generation of wave breaks and stabilized the activation patterns.