Automated precision current delivery: an alternative method for cardiac defibrillation.

Substantial evidence suggests that the current associated with the discharge is a more precise predictor of defibrillation success than is the total energy of the discharge. However, virtually all commercially available defibrillators are calibrated in terms of energy. This article describes an alternative type of experimental defibrillator, which provides a precisely controlled current throughout the discharge waveform, independent of the load presented to the discharge electrodes (or "paddles").

Ibutilide: enhanced defibrillation via plateau sodium current activation.

Reductions in current and energy requirements for defibrillation have previously been ascribed to type III antiarrhythmic agents that block outward potassium conductance. This study investigated the effect on defibrillation of ibutilide, a type III antiarrhythmic agent that prolongs action potential duration by activating the sodium component of the plateau inward current. Pentobarbital-anesthetized dogs were subjected to serial episodes of ventricular fibrillation lasting 10 s.

Transepicardial defibrillation dose response: current versus energy.

In pentobarbital-anesthetized dogs, we compared the relative efficacy of current versus energy in applying the dose response method in transcardiac defibrillation. Damped sinusoidal shocks via epicardial patches were administered by a custom defibrillator permitting precise current delivery. Following the establishment of an initial estimated defibrillation threshold for energy and current, the dose response method was performed with regard to either energy defibrillation threshold (group E, n = 8) or current defibrillation threshold (group C, n = 8).