Implantable Cardioverter Defibrillator (ICD)
An implantable cardioverter defibrillator (ICD) is a small electronic device connected to the heart. It is used to continuously monitor and help regulate irregular life-threatening heart rhythms (arrhythmias) that originate in the lower chambers of the heart (ventricles). When the ICD senses the life-threatening arrhythmia, it delivers a shock (defibrillation). This shock immediately resets your rhythm back to normal and prevents sudden cardiac arrest.
Transvenous or “traditional” ICDs are implanted under the skin just below the collarbone. It consists of a pulse generator and wires (leads). The pulse generator contains the battery and a tiny computer. One or more lead wires connect the pulse generator to specific locations in the heart.
Unlike the transvenous ICDs, which utilize wire leads inserted directly into the heart through a large vein, subcutaneous ICDs use a subcutaneous (beneath the skin) electrode that rests near (but not in) the heart to both sense lethal heart arrhythmias and deliver therapy. The electric pulse generator is implanted just below the armpit.
An ICD can also be programmed to work as a basic pacemaker as needed. Sometimes after a shock is delivered, the heart may beat too slowly. The ICD has a "back-up" pacemaker, which can stimulate the heart to beat faster until the normal heart rhythm returns. The ICD can act as a pacemaker any time the heart rate drops below a preset rate.
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How to Prepare for the Procedure
Prior to the procedure, your doctor and treatment team will explain to you what to expect before, during and after the procedure and potential risks of the procedure. Talk to your doctor about:
- All medications, herbal products and dietary supplements you are currently taking and ask for their recommendations about each.
- Diabetes and how to adjust your medicine on the day of the procedure.
- Radiation exposure, especially for those that are pregnant.
- Any allergies to medicines, latex, tape, iodine, and anesthetic agents.
- Any history of bleeding disorders.
- Any body piercings on your chest or abdomen.
Other recommendations include:
- Eat a normal meal the evening before the procedure. However, do not eat, drink or chew anything after midnight before your procedure. If you must take medications, only take them with sips of water.
- Leave all jewelry at home.
- Remove all makeup and nail polish.
- Wear comfortable clothing when you come to the hospital.
- If you normally wear dentures, glasses, or hearing devices at home, plan to wear them during the procedure.
What to Expect Before the Procedure
To determine whether you need an ICD or not, your doctor might perform a variety of diagnostic tests, including:
- Blood tests
- Cardiac Catheterization
- Computed Tomography (CT scan)
- Magnetic Resonance Imaging (MRI)
- X-Rays
- Echocardiogram (ECHO)
- Electrocardiogram (EKG/ECG)
- Electrophysiology (EP) study
- Stress Test
What to Expect During the Procedure
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ICD implantation is a non-invasive procedure (no incisions required / small puncture / low to moderate sedation); however, placement of the ICD under the skin will require a few small incisions. The procedure itself usually takes 1 to 3 hours to complete. This procedure is usually performed in a cardiac catheterization lab. Check with your doctor about the details of your procedure. In general:
- You will change into a hospital gown.
- A nurse will start the intravenous (IV) line in your arm which will administer medications and fluids during the procedure.
- Usually, you will receive a sedative to help you relax. However, you will likely remain awake during the procedure.
- A local anesthetic will be injected into the skin at the insertion site.
- Once the anesthetic has taken effect, your doctor will make a small incision at the insertion site (usually under the collarbone).
- Through this opening, your doctor will insert a catheter (ICD lead wire included) and advanced into the heart.
- Once the lead wire is inside the heart, it will be tests to verify proper location and that it works. There may be several wires inserted, depending on the type of device chosen.
- For subcutaneous ICDs (S-ICDs), one or two small incisions are made near the top and bottom of the sternum. The lead wire is then tunneled underneath the skin next to the sternum and from the sternum to the incision on the left side of the chest.
- The ICD generator will be slipped under the skin through the incision (just below the collarbone for traditional ICDs and on the left side of the chest for S-ICDs) after the lead wire is attached to the generator.
- Once the ICD is in place, your doctor will test it and program it for your heart rhythm problem. Testing the ICD may require speeding up your heart and then shocking it back into rhythm.
- Once the procedure is complete, the skin incision will be closed with a closure device or sutures.
What to Expect After the Procedure
After the procedure, you may be taken to the recovery room for observation or returned to your hospital room. Either way, you will stay overnight. Usually you will be able to go home the day after your ICD was implanted. Other guidelines:
General Guidelines
- A nurse will monitor your vital signs, the insertion site, and circulation and sensation in the affected leg or arm.
- A chest X-ray will be done after the device implant procedure to check your lungs as well as the position of the device and lead(s).
- Tell your nurse right away if you feel any chest pain or tightness, or any other pain, as well as any feelings of warmth, bleeding, or pain at the insertion site.
- You must stay in bed for several hours as recommended by your doctor.
- Your doctor will give you instructions to follow during your recovery.
ICD Programming
- The ICD will require regular evaluation (remotely and/or in person). Your doctor will tell you when and how this is done.
ID Card
- You will be given an ID card that identifies you as having an ICD.
- Make sure to always carry this ID card with you.
- Tell all of your health care providers that you have an ICD.
Special Precautions: Several types of devices and machines may interfere with your ICD. Try to avoid them, or at least minimize your exposure to them. The American Heart Association lists the following:
- Devices that may interfere with ICDs: Anti-Theft systems; metal detectors for security; cell phones; MP3 players/headphones; radios; magnets; power-generating equipment; among others.
- Devices that pose little to no risk: Household appliance and electronics; garage, shop and lawn equipment; office machinery and electronics; tanning beds; hot tubs; casino slot machines; massage chairs; salon-style hair dryers; among others.
- Medical procedures that may pose a risk: Extracorporeal Shock-Wave Lithotripsy (EWSL); magnetic resonance imaging (MRI); radiofrequency ablation or microwave ablation; computed tomography (CT) scans; high-frequency, short-wave or microwave diathermy; among others.
- Medical procedures that pose limited risk: Electrocardiogram (EKG/ECG); echocardiogram (ECHO); acupuncture; ultrasounds; laser surgery; among others external defibrillation; Pet emission tomography (PET scans); bone density tests; among others.
Do you have a question? Request more information and we will connect you with an RWJBarnabas Health cardiovascular expert.