Treatment with an implantable cardioverter-defibrillator (ICD) represents a prognostic but not symptomatic therapy. It should therefore be restricted to patients where an improvement of prognosis is possible and reasonable. ICD implantation should only be performed in patients with a life expectancy of at least 1 year at reasonable quality of life. The decision in which patient improvement of prognosis is no longer a desirable target is problematic, both medically and ethically. It is not entirely clear in which elderly patient an ICD therapy can convey prognostic benefit despite comorbidity and competitive life-threatening diseases, as it is unclear how old age should be defined. In primary prophylaxis of sudden cardiac death, data on a prognostic benefit of the ICD in elderly patients are less clear than in secondary prophylaxis since short-term mortality due to other causes is higher in the elderly. However, elderly ICD patients have a similar rate of appropriate ICD therapy as younger patients. Complications at ICD implantation or long-term lead failure do not occur more frequently in elderly patients and therefore do not represent a reason to withhold ICD implantation in elderly patients or to set an age limit above which ICD implantation should no longer be performed. The ICD indication in elderly patients should be individualized depending on remaining life expectancy, comorbidity, "biological age" and patient preferences which play a particularly important role in elderly patients. Aspects of a potential improvement in quality of life by the ICD which may also serve as a system for antibradycardiac or resynchronization treatment should be included into considerations. Deactivation of at least shock therapy should be discussed in elderly patients fitted with an ICD if the subject is brought up by the patient or if clinical deterioration suggests the need to talk about a "do not resuscitate" order. This talk should be performed before death is imminent and before an electrical storm in terminal illness leads to multiple shocks by the active device.
