An implantable cardioverter defibrillator (ICD) is a small device that's placed in your chest or abdomen. This device uses electrical pulses or shocks to help control life-threatening, irregular heartbeats, especially those that could lead the heart to suddenly stop beating (sudden cardiac arrest). If the heart stops beating, blood stops flowing to the brain and other vital organs. This usually causes death if it's not treated in minutes.
Sudden cardiac arrest (SCA) is a condition in which the heart suddenly and unexpectedly stops beating. When this happens, blood stops flowing to the brain and other vital organs.
SCA usually causes death if it's not treated within minutes.