ABSTRACT
An electric shock delivered to the heart attempts to terminate fibrillation by changing the transmembrane potential of cardiac cells. The success or failure of the shock is a function of both the level of shock-induced change in transmembrane potential as well as the preshock electrical activity in the myocardium. The series of two chapters on defibrillation included in this book dissect these underlying processes: The preceding chapter [1] examined the interaction between the applied electric field and the tissue structure in establishing a shock-induced change in transmembrane potential. The present chapter explores how this induced transmembrane potential alters the preshock electrical state of the tissue to result in a successful or failed defibrillation attempt. Both chapters describe insight achieved through computer simulations of the defibrillation process, underscoring the role of modeling and simulation as an indispensable research tool.
