Implantable Cardioverter Defibrillators (ICD)
An implantable cardioverter-defibrillator (ICD) is a small battery-powered electrical impulse generator that is implanted in patients who are at risk of sudden cardiac death due to ventricular fibrillation and ventricular tachycardia. The device is programmed to detect cardiac arrhythmia and correct it by delivering a brief electrical impulse to the heart. In current variants, the ability to revert ventricular fibrillation has been extended to include both atrial and ventricular arrhythmias. There also exists the ability to perform biventricular pacing in patients with congestive heart failure or bradycardia. The process of implantation of an ICD is similar to implantation of a pacemaker. Similar to pacemakers, these devices typically include electrode wire(s) that pass through a vein to the right chambers of the heart, usually lodging in the apex of the right ventricle. The difference is that pacemakers are more often temporary and are generally designed to correct bradycardia, while ICDs are often permanent safeguards against sudden arrhythmias.