(373h) Optimal Defibrillatory Shock

Patients with congestive heart failure can die suddenly and unpredictably from arrhythmia despite the use of proven medical therapies. In those patients, one of the most efficient therapies to prevent sudden cardiac death is the therapy with an implantable cardioverter-defibrillator (ICD). A defibrillatory shock is the application of a large current to the cardiac tissue that undergoes spatially non-uniform excitable patterns. We consider a general cardiac tissue model and provide simplifications that illustrate the usefulness of the model [1], in order to pose a problem of finding the optimal defibrillatory shock that will annihilate a characteristic ventricular fibrillation excitable pattern. In other words, what is the optimal current input injection in given finite time that drives a system to the rest potential for the given cardiac system described by the nonlinear parabolic differential equation and the FitzHugh-Nagumo-type dynamics. The answer to this question provides a novel insight into an amplitude current strength and the shape of the current applied to the tissue to the clinical practitioners who are highly interested in the features of a successful defibrillatory shock.

[1]. A Biophysical Model for Defibrillation of cardiac Tissue, James P. Keener, A. V. Panfilov, Biophysical Journal, vol 71, 1996, 1335-1345.