Cardiac ICD

IMPLANTABLE CARDIOVERTER DEFIBRILLATORS (ICDS)

An ICD is an electronic device designed to stop rapid, life-threatening heart rhythms. If the heart has stopped (cardiac arrest) or is experiencing rapid, abnormal 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 uses two approaches to stop rapid, abnormal heart rhythms. The device can stimulate the heart to beat faster than the abnormal rate, which is called overdrive pacing, or it can deliver one or more electrical impulses directly to the heart to stop the rhythm.

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 two types of ICDs: single and dual chamber 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.