Implantable Cardioverter Defibrillator
An implantable cardioverter defibrillator is a device for people who are prone to life-threatening rapid heart rhythms originating from the lower chambers of the heart. If the heart has stopped (cardiac arrest) or is experiencing rapid, abnormal heart rhythms (life-threatening arrhythmias) that cannot be controlled by drugs or other approaches, this device may be used. It may also be used in patients with very weak heart muscle where there is an increased risk of developing dangerous heart rhythms.
The defibrillator is placed in a pocket under the skin of the chest. The device consists of leads and a pulse generator. The leads monitor the heart rhythm and deliver the energy for pacing, cardioversion and/or defibrillation. The generator contains the battery and a tiny computer that processes information to determine the heart's rhythm.
There are three types of ICDs: single, dual chamber and biventricular devices. In a single-chamber ICD, a lead is attached to the right ventricle. In a dual-chamber ICD, leads are attached to the right atrium and the right ventricle. There is also a biventricular ICD, in which leads are attached in the right atrium, the right ventricle and the left ventricle. The biventricular ICD is for patients who have had heart failure to provide cardiac resynchronization therapy.