Implantable Cardioverter Defibrillator

An implantable cardioverter defibrillator (ICD) is a surgically implanted cardiac device that corrects life-threatening arrhythmias (abnormal heart rhythms), by increasing the heartrate.

Who Needs an Implantable Cardioverter Defibrillator?

An ICD is often recommended after a sudden cardiac arrest, if no treatable cause is identified. The device may also be recommended if the risk for experiencing a life-threatening heart rhythm is considered high. Common examples include ventricular tachycardia and ventricular fibrillation.

An ICD detects a life-threatening change in heart rhythm and delivers therapy to prevent sudden cardiac arrest or death. Certain cardiac conditions increase the risk of a life-threatening heart rhythm, including:

• Heart failure.
• Prior heart attack(s).
• Inherited or acquired cardiomyopathy (a disorder that causes enlargement or thickening of the heart muscle, which forces the heart to work harder).
• Inherited heart rhythm disorders caused by abnormal ion channel function.

What to Expect Before, During and After Surgery

Before the procedure

Your healthcare team will ask you not to eat or drink for 8 hours before the ICD implantation surgery. Be sure your healthcare team knows all the medications you take. Your team will let you know what medications you can or cannot take before your procedure.

Arrange to have someone drive you home after your ICD procedure. You’ll also need someone to help you while you are recovering.

During the procedure

After you receive an IV, you’ll be taken to the electrophysiology laboratory. Most procedures are done under light sedation with local anesthesia. Depending on your condition and health, you may receive general anesthesia, which means you’ll be asleep throughout the procedure. The procedure typically takes a few hours.

The implantation procedure varies depending on the type of ICD you receive:

• Transvenous: This type of ICD is usually implanted below the collarbone on either side of the chest. Wires (called leads) from the ICD are attached to the heart.
• Subcutaneous: This type of ICD is implanted below one of the armpits and attached to a sensor (called an electrode) that runs along the breastbone. There are no leads connected to the heart.

Transvenous ICD Implantation Procedure

To implant a transvenous ICD, your doctor will insert one or more leads into a blood vessel in the chest. One end of each lead is attached to the heart and the other to the ICD.

The procedure usually takes a few hours. Once the device is in place it will be programmed to recognize and treat any life-threatening heart rhythms.

Subcutaneous ICD Implantation Procedure

To implant a subcutaneous ICD, your doctor will make incisions on the left side of the chest. Another incision is made near the sternum to implant the electrode and connect it to the ICD implant.

After the procedure

Most patients can go home the same day of their procedure or the following day. Full recovery takes about four to six weeks.

You may be advised not to lift anything heavier than 10 to 15 pounds and to avoid pulling, pushing or twisting the arm on the side of the defibrillator for a few weeks. You may also be instructed not to raise that arm above your shoulder for several weeks.

Benefits of Implantable Cardioverter Defibrillators

The main benefit of an ICD is its ability to treat life-threatening arrhythmias and prevent death from cardiac arrest. In addition, an ICD can provide your cardiologist with important information about your heart to help make treatment decisions.

Risks and Potential Complications of Implantable Cardioverter Defibrillators

Getting an ICD is generally safe. However, as with any procedure, the implantation has certain risks, including:

• Bleeding or bruising.
• Swelling.
• Damage to blood vessels from the leads.
• Infection of the incision site.
• Collapsed lung (air leaking into the space between the lung and chest wall).
• Cardiac perforation (a tear or rupture in the heart chamber wall) or cardiac tamponade (pressure on the heart caused by excess blood and fluid in the sac surrounding it).

Follow-up Care

Your physician will check your defibrillator several times a year, in the office and remotely if your device has a remote monitor. These checkups will:

• Check that your device is monitoring your heartbeat correctly.
• Verify how many therapies like anti-tachycardia pacing or shocks (if any) have been delivered.
• Estimate how much power is left in the battery.
• Check for any other abnormal heart rhythms such as atrial fibrillation.

Most ICDs use lithium batteries that last seven to nine years. When the battery reaches the last three months of full function, the ICD will be replaced with a new one. The replacement is typically an outpatient procedure and does not require replacement of the leads.

Lead Extraction

ICD leads are designed to stay attached to the heart permanently, where they’re held in place by scar tissue. However, sometimes leads need to be removed. The procedure to remove them is called lead extraction.