Implantable cardioverter-defibrillators (ICDs)
Implantable cardioverter-defibrillators (ICDs)
An implantable cardioverter-defibrillator (ICD) — a pager-sized device which is implanted in your chest — may reduce your risk of dying if your heart goes into a dangerous rhythm and stops beating (cardiac arrest). You may need an implantable cardioverter-defibrillator if you have a dangerously fast heartbeat (ventricular tachycardia) or a chaotic heartbeat that makes it so your heart can't supply enough blood to the rest of your body (ventricular fibrillation).
Implantable cardioverter-defibrillators work by detecting and stopping dangerous, abnormal heartbeats (arrhythmias). An implantable cardioverter-defibrillator continuously monitors your heartbeat and delivers electrical shocks to restore a normal heart rhythm when necessary.
Why it's done
You may have seen TV shows in which a hospital worker or paramedic "shocks" an unconscious person out of cardiac arrest with a pair of electrified paddles. An implantable cardioverter-defibrillator (ICD) does the same thing, only internally and automatically when it detects your heartbeat is abnormal.
An ICD is surgically placed under your skin, usually below your left collarbone. One or two flexible, insulated wires (leads) run from the ICD through your veins to the lower chambers of your heart.
Because the ICD constantly monitors for abnormal heart rhythms and instantly attempts to correct them, it helps treat cardiac arrest even if you're hours away from the nearest hospital.
How an ICD works
Usually, only one shock is needed to restore a normal heartbeat. Sometimes, however, you may have two or more such shocks during a 24-hour period. Frequent shocks in a short time period are known as ICD storms, and they may understandably cause you to worry. If you experience ICD storms, you should seek emergency care to see if your ICD is working properly or if you have a problem that's making your heart beat more abnormally. If necessary, the ICD can be adjusted to deliver the appropriate number of shocks. Additional medications may be needed to make your heart beat regularly and decrease the chance of an ICD storm.
Who needs an ICD?
The procedure to implant an ICD has some risks, but they are rare. Risks of the procedure to implant an ICD include:
How you prepare
To determine whether you need an ICD, your doctor may perform any of these diagnostic tests:
Your doctor will give you specific instructions on what to do immediately before your surgery to prepare. It's likely you'll be asked not to eat or drink anything for at least eight hours before your surgery. Talk to your doctor about any medications you take, and whether or not you should continue to take them before your procedure to implant an ICD.
What you can expect
During the procedure
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
An ICD is usually programmed to perform these functions:
An ICD can also be programmed to perform additional functions, which include:
Treating pain after your procedure
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.
Implantable cardioverter-defibrillator (ICD)
An ICD works to regulate your heartbeat by delivering shocks to your heart when it detects your heart is beating abnormally. ...
Because of their capabilities, ICDs have become standard treatment for anyone who has survived cardiac arrest and are used increasingly in individuals who are at high risk of sudden cardiac arrest. If you have an ICD, your risk of sudden death from cardiac arrest is significantly lower than it would be if you were treated only with medications to correct your heartbeat.
If you're at high risk of ventricular tachycardia and ventricular fibrillation, an ICD may be your best defense against cardiac arrest. Once you have an ICD, it's likely you'll need to keep it for life. Although the electrical shocks may be unsettling, they're evidence that the ICD is effectively treating your heart rhythm problem and protecting you from sudden death. Talk to your doctor about how to best care for your ICD.
After your procedure, you'll need to take some precautions to avoid injuries and make sure your ICD works properly.
Devices that present little or no risk to your ICD include microwave ovens, televisions and remote controls, radios, MP3 players, toasters, electric blankets, electric shavers and electric drills.
The American Heart Association's guidelines discourage driving during the first six months after your procedure if your ICD was implanted due to a previous cardiac arrest or ventricular arrhythmia. If you experience no shocks during this period, you will likely be able to begin driving again. But if you later experience a shock, with or without fainting, tell your doctor and follow his or her recommendations.
In most cases, you will need to stop driving until you've been shock-free for another six months. There is some controversy regarding this topic. For example, the European Heart Rhythm Association recommends waiting only three months before driving if your ICD was implanted due to a previous cardiac arrest or arrhythmia, while the American Heart Association recommends waiting six months. Talk to your doctor to get advice for your situation.
If you have an implantable cardioverter-defibrillator but have no history of life-threatening arrhythmias, you can usually resume driving within weeks after your procedure, with your doctor's approval, if you've had no shocks. Discuss your specific situation with your doctor. You usually can't get a commercial driver's license if you have an ICD.
ICDs and end-of-life issues
If you have an ICD implanted and are concerned about turning it off in an end-of-life situation, talk to your doctor. You may also want to talk to family members or another person designated to make medical decisions for you about what you'd like to do in end-of-life care situations.
Last Updated: 2010-11-19
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