What you can expect

By Mayo Clinic Staff

Usually, the procedure to implant an ICD can be performed with numbing medication and a sedative that relaxes you but allows you to remain aware of your surroundings.

The procedure typically takes one to three hours. During surgery, a flexible, insulated wire (lead) is inserted into a major vein under or near your collarbone and guided, with the help of X-ray images, to your heart. The ends of the leads are secured to your heart's bottom pumping chambers (ventricles), while the other ends are attached to the shock generator, which is usually implanted under the skin beneath your collarbone.

After the procedure

After implantation, your doctor will test your ICD and program it to treat your specific heart rhythm problem. Testing the ICD requires shocking your heart. You'll be given general anesthesia so that you aren't awake during the test. You stay in the hospital one or two days, and the ICD may be evaluated one more time before you're discharged. Any additional tests of your ICD usually don't require surgery.

An ICD is usually programmed to perform these functions:

  • Cardioversion. When the ICD detects a dangerously fast heartbeat, it delivers an electrical shock that converts the fast heartbeat into a slower, normal heartbeat.
  • Defibrillation. Sometimes cardioversion fails, and your heartbeat either quickens or beats chaotically. Other times, a chaotic heartbeat develops spontaneously. When the ICD detects either of these life-threatening rhythms, it delivers a stronger electrical shock that resets (defibrillates) your heart to start beating normally.

An ICD can also be programmed to perform additional functions, which include:

  • Anti-tachycardia (tak-ih-KAHR-dee-uh) pacing. If you experience an unusually fast heart rate, the ICD delivers painless, low-energy impulses that pace or stimulate the heart to beat at a rate that prompts it to return to a normal rhythm. This can prevent the need for cardioversion or defibrillation.
  • Anti-bradycardia (brad-e-KAHR-dee-uh) pacing. When the heartbeat is abnormally slow (bradycardia) because of a heart condition or medication, a standard pacemaker is the typical treatment advised. People with ICDs, however, sometimes develop bradycardia as a result of the shock the ICD delivers in response to ventricular tachycardia or ventricular fibrillation. In this situation, the ICD can sense the slow heart rate and function as a pacemaker, delivering low-energy impulses that stimulate the heart to beat normally.
  • Recording heart activity. The ICD records information about variations in your heart's electrical activity and rhythm. This information helps your doctor evaluate your heart rhythm problem and, if necessary, reprogram your ICD.
  • Biventricular pacing. Unlike a standard pacemaker, which stimulates only one side of your heart's main pumping chamber (the right ventricle), a biventricular pacemaker stimulates both the right and left ventricles to make the heart beat more efficiently. A special type of ICD — a combined biventricular pacemaker with ICD — can do the same thing. Biventricular pacing is particularly valuable for some people with heart failure whose hearts' electrical systems don't work normally.

Treating pain after your procedure

After surgery you may have some pain in the incision area, which can remain swollen and tender for a few days or weeks. Pain medication often is initially prescribed; you can take nonaspirin pain relievers, such as acetaminophen (Tylenol, others) or ibuprofen (Advil, Motrin IB, others), as your pain lessens. Unless your doctor instructs you to do so, don't take pain medication containing aspirin because it may increase the risk of bleeding.

As a precaution, you won't be able to drive yourself home after your procedure, so be sure to make arrangements to get home another way.

Jun. 04, 2013