Computer simulation of ventricular fibrillation and of defibrillating electric shocks

Computer simulations of the depolarizing wave inside a bidimensional ventricle element using the Huyghens principle are described. The authors simulate permanent conditions leading to uncoordinated contraction of the ventricular fibers induced by unidirectional blocks. They study the influence of anisotropic conduction on the initialization of reentry. They calculate the critical size of the unidirectional block required to generate a reentry for normal and ischemic tissues, for both isotropic and anisotropic conduction. Once a permanent malfunction is initialized, they simulate electric shocks with different percentages of cells depolarized by the shock. They show that in order to be sure to stop the rotating waves, it is necessary to depolarize all the excitable cells. Even a few nondepolarized cells are sufficient to reinitialize several periodic rotating waves