Test of four defibrillation dosing strategies using a two-dimensional finite-element model

The most widely used defibrillation dosing strategy is that adopted by the American Heart Association in 1986. However, several alternative dosing strategies have been proposed to match delivered energy to the individual requirements of defibrillation subjects. In this study, two-dimensional finite element methods are used to investigate the performance of four of these dosing strategies applied to three thoracic models representative of men and women of different thoracic aspect ratios. From the resulting current density distributions, the relative effectiveness of the following dosing strategies are evaluated and compared: constant current; current proportional to body weight; constant energy; energy proportional to body weight. Our results show that the strategy of applying current proportional to subject body weight with a current dose of 0.58 A kg-1 was able to defibrillate all three subjects with only minimal overexposure of any one of them. None of the other dosing strategies examined could be made to successfully defibrillate all three subjects without significantly overexposing at least one.