What is an implantable cardioverter-defibrillator?
An implantable cardioverter-defibrillator (ICD) is a battery-powered medical device implanted under the skin that delivers an electric shock to restore a normal heart rhythm.
The device is roughly the size of a pager or stopwatch. It's usually placed just below the collarbone and connected to the inside of the heart by thin leads threaded through blood vessels. An ICD continuously monitors and records your heart rhythms and typically has a battery life of 5-7 years.
When the ICD implantation detects an arrhythmia, an abnormal or irregular heart rhythm, it generates an electric pulse that returns your heartbeat to a regular rate. While the shock is perceptible, it is very effective and lasts only a second or two.
Why would I need an ICD?
If you've had a heart attack, heart surgery or have a history or genetic predisposition for conditions associated with arrhythmia, you may need an implantable cardioverter defibrillator.
To determine whether that’s the case, your physician may recommend tests, including an EKG or echocardiogram. They may also suggest an electrophysiology study, where catheters are inserted into the heart to study your heart’s electrical system. You may also need to wear a Holter monitor that records your heartbeat for 24 to 48 hours.
How is an ICD implanted?
ICD implantation is performed on an outpatient basis, or outside a hospital, by a clinical cardiac electrophysiologist (EP). These specialists are trained to diagnose and treat arrhythmias using various techniques, including less invasive surgical procedures.
During the implantation procedure, you will either receive local anesthetic to numb the surgical site, or be put to sleep using general anesthesia.
The EP will then make a small incision near your collarbone, where they will insert the pulse generator just beneath your skin. One or more wires, or leads, will then be threaded through a vein and into your heart. Once that’s completed, you’ll be moved to recovery for monitoring.
It usually takes about two weeks for the pulse generator and leads connect, at which time, you will return of a visit so your care team can confirm the device is working properly.
Can I live a normal life with an ICD?
After discharge, you may experience some pain at the implantation site. Your physician may instruct you to limit using your arm nearest the ICD to prevent sudden movements from dislocating the device or the leads in your heart. You can typically return to your regular activities after about six weeks.
You should be able to perform most of your usual activities with an implantable cardioverter-defibrillator. Strong magnetic fields can affect an ICD's operation, so you'll be advised to avoid metal detectors, power generators and other devices with strong magnets or electrical signals.
Conditions Treated by an ICD
Are pacemakers the same as ICDs?
Some ICDs come equipped with pacemakers, but each performs a unique function. An ICD delivers an electric shock to correct an abnormal heart rhythm. A pacemaker stimulates the heart to beat faster when the heart rate is too slow.
This condition is called bradycardia. Pacemakers can also control other abnormal heart rhythms. Both devices get implanted in the body and operate continuously. While most ICD batteries last 5-7 years, the batteries in a pacemaker can last 12 years or longer.