Comparison of defibrillation resistance of various diameter electrodes

The objective of this study was to determine the difference in the resistance of a custom 3 Fr. defibrillation electrode with that of a 9.6 Fr. defibrillation electrode in the canine. An additional objective was to compare these results with those obtained using tank tests and an analytical model of the electrodes. Although thinner leads can be made more reliable and may provide clinical benefit, their increased defibrillation resistance could negatively impact defibrillation efficacy. Therefore, in this study the defibrillation resistance was measured for various electrode diameters in the canine, a tank, and an analytical model to better understand the resistance behavior of defibrillation electrodes. The resistance was the electrostatic resistance in the model, and the leading edge resistance of a defibrillation shock in both the tank and the canine. The resistance increased up to 13 ohms when the diameter was reduced from 0.120" to 0.016" with similar results in the tank, the model, and the canine. The model correctly calculated the differences in the resistance despite the fact that it contained no consideration for electrochemical and interfacial components. Therefore, these elements are unlikely to have a significant effect on defibrillation resistance