An implanted defibrillator or AICD is an electronic device that is placed in your body to help control the speed and pattern of your heart rate by constantly monitoring your heart rate and rhythm. When it detects a very fast, abnormal heart rhythm, it delivers energy to the heart muscle. This causes the heart to beat in a normal rhythm again. The AICD is made up of two parts, a generator and leads.The generator houses the battery and a tiny computer. Energy is stored in the battery until it is needed. The computer receives information from the leads which are tiny wires that monitor the heart’s rhythm and delivery energy from the generator to determine what rhythm is occurring. for pacing, cardioversion and/or defibrillation. The AICD normally works as a pacemaker and prevents slow heart beat until a potentially “killer rhythm” emerges and then it delivers the shock energy to the heart automatically.