Effect of Intravenous Lidocaine, Used to Attenuate Pain With Propofol Injection, on Defibrillation Threshold Testing

Summary: The purpose is to observe the incidence of successful defibrillation on the first attempt during implantation of an implantable cardioverter-defibrillator (ICD) among patients who receive a standard dose of intravenous lidocaine (for attenuation of pain associated with propofol injection) versus patients who do not receive an intravenous lidocaine dose. During implantation of an ICD, defibrillation threshold (DFT) testing is performed. DFT is calibrated as the lowest energy delivered by the ICD that will successfully terminate malignant arrhythmia. Lidocaine, a routine anesthetic agent, is also identified as an antiarrhythmic drug. Experimentally, lidocaine has been shown to increase thresholds during DFT' testing due to the drugs dual effect. The rationale behind this project is that the lidocaine may yield falsely elevated DFT, resulting in higher calibration of the ICD device. This alteration can affect ICD battery and overall ICD life. Comparisons between study groups may elucidate effects of IV lidocaine on DFT.