Chronic effects of epicardial patch electrodes on transthoracic defibrillation

Patients occasionally have epicardial patch electrodes implanted without a functional generator, and may need to be defibrillated transthoracically. Studies in acute animal models indicate these patches adversely effect the ability to defibrillate externally, on the day of surgery. However a study of patients 3 weeks after implant surgery, failed to demonstrate this adverse effect. Here a chronic animal model is used to quantify the effect of epicardial patch electrodes on transthoracic defibrillation after recovery from the surgery.