Will my device need to be replaced? How often?

Eventually yes. You may hear talk of battery replacement, but really the whole ICD is replaced because the battery is sealed in a titanium case.   Here's what typically happens. Your doctor will open the pocket and disconnect the device from the leads. He or she will check to see if the leads can be reused.   If not, the leads are usually "capped" (meaning deactivated) and left in place with new leads implanted. Sometimes leads are surgically removed. Many variables can affect the battery life of a defibrillator, such as type, purpose, and the frequency of treatment delivery, so your doctor will give you the best estimate.