Internal Cardioverter Defibrillator (ICD)

ICDAn implantable cardioverter defibrillator (ICD) is a device that can detect dangerously fast heartbeats and give a lifesaving shock to correct the heart's rhythm.   Today all ICDs also act as pacemakers and can prevent slow heart rhythms as well.

An ICD is most often implanted below the collarbone in a pocket under the skin. A different type of defibrillator may be placed along a patient's left side. Like pacemakers, an ICD contains computer circuitry, a battery, and wires called "leads" that go through a vein into the heart. The leads stay in contact with the heart muscle on one end, while the other end is connected to the generator. These are called transvenous ICDs. Transvenous ICDs also act as pacemakers and can treat slow heart rhythms by pacing as well.

A different type of ICD called a subcutaneous ICD may be placed along the patient’s left side. The lead is tunneled under the front of the chest and does not go directly to the heart. It is very effective at treating life-threatening heart rhythms, but does not provide pacemaker function. The battery in the ICD generator lasts 5-8 years and the ICD must be replaced when it runs out. The ICD is programmed to record signals from the heart. All of the heart rhythm information is stored in the ICD memory.

This information is available to your doctor at routine clinic visits and through remote data transmissions from home. ICD follow up is very important for each patient, to make sure the ICD battery is good, and that the device is working properly.