This is a good conversation to have with your doctor. Your doctor prescribed an ICD for you because you are at risk for sudden cardiac arrest (SCA). SCA is caused by a very fast and irregular heart rate. The only treatment for SCA is to stop the irregular heart rhythm with defibrillation, using either an external defibrillator or an implantable one (ICD). Your ICD protects you from SCA by monitoring your heart 24 hours a day. If it senses a dangerous rhythm, it delivers a shock to stop it. That being said, sometimes a person may have a change in medical condition and no longer need an ICD. This situation, however, is not very common.