COMPUTER-SIMULATION OF VENTRICULAR-FIBRILLATION AND OF DEFIBRILLATING ELECTRIC SHOCKS - EFFECTS OF ANTIARRHYTHMIC DRUGS

We present computer simulations of the propagation of the depolarizing wave through the ventricular wall based on the Huygens' construction method. We simulate different self-sustained conduction troubles related to fibrillation. We calculate the critical size of myocardium needed to induce reentries in either normal or ischemic tissues for isotropic and anistropic conduction conditions. Then, in order to stop the reentrant activity, simulation of electrical shocks is achieved by depolarizing different percentages of excitable ventricular cells. It is shown that all the excitable cells must be simultaneously depolarized in order to block the reentry. The model is also extended to pharmacological applications on antiarrhythmic drugs. We simulate a decrease in the refractory period leading to spatial and time adjustments of the size of the reentry. We also simulate effects of class III antiarrhythmic drugs increasing the refractory period and blocking the reentry.