What happens if your body rejects the defibrillator?

Rejection. A AICD is a metal encased device, rejection is not an issue. The body will encase the device with fibrous tissue. Rejection is an issue with body tissue and not a metal device. So be assured.
AICD. the defibrillator is not made of a material that can be rejected. There are possible problems but rejection isn't one of them.