Automatic Implanted Cardioverter Defibrillators (AICDs or ICDs)

ICDs continuously monitor the heart rhythm, automatically function as pacemakers for heart rates that are too slow, and deliver lifesaving shocks if a dangerously fast heart rhythm is detected. ICDs are 99 percent effective in stopping life-threatening arrhythmias and are the most successful therapy to treat ventricular fibrillation, the major cause of sudden cardiac death.

A defibrillator is inserted into the patient's heart and chest to send out a small amount of electricity when needed to jolt heart rhythm back to normal.