This is a relatively small device most often placed within the chest under the collar bone. It has wires that attach into the heart. The purpose of this device is to use electrical pulses or shocks to help control life-threatening irregular heartbeats, primarily those that cause sudden cardiac arrest [SCA]. SCA is a condition in which the heart suddenly and unexpectedly stops beating, which usually leads to death. The device is primarily indicated in two types of settings:1. in patients who are actively having these types of life-threatening heart rhythm irregularities which has been documented while they have been on a heart rhythm monitor,
2. or in patients who have high risk medical conditions (such as a weakened heart muscle), and are expected to have this type of life-threatening abnormal heart rhythm.