The present invention reduces patient risks associated with RF-induced thermogenic tissue damage and with pulsed gradient-field-induced arrhythmias by using a defibrillator lead having a self-healing dielectric material that prevents induced voltages from MRI equipment from damaging an ICD or causing unintended defibrillation shocks to a patient. Another aspect of the present invention utilizes a sliding contact arrangement to prevent induced voltages from MRI equipment from being electrically coupled to an ICD thereby reducing patient risks associated with RF-induced thermogenic tissue damage and with pulsed gradient-field-induced arrhythmias.