Effects of Monopolar Electrocautery Use During Surgery on Implanted Cardiac Defibrillators

This observational protocol will evaluate the effects of monopolar electrocautery (ME) on implantable cardioverter defibrillators (ICDs) in patients undergoing surgery. ME can cause electromagnetic interference (EMI) leading to ICD damage or inadvertent ICD discharge (shocks). Recommended practice calls for the preoperative reprogramming of ICDs when ME will be used to prevent patients from receiving inadvertent shocks. This requires the presence of someone trained in ICD programming, but a trained person is not always readily available. In this study the investigators will reprogram ICDs prior to surgery according to current practice, but will also record what would have happened had the ICD reprogramming not occurred ("detection on" but "therapy off"). In addition, the investigators will evaluate the effect of the location of the electrosurgery unit (ESU) return pad on the incidence of EMI. The investigators hypothesize that directing the current return path away from the ICD will result in lower EMI rates than previously described.