An implantable cardioverter-defibrillator (ICD) is a type of medical device. It keeps track of your heartbeat and, when needed, sends an electric current through your heart.
The ICD is smaller than a cell phone. It has two main parts: a pulse generator and a lead. The pulse generator monitors your heartbeat. It is like a small computer that runs on a battery. The lead is a wire from the pulse generator to the inside of your heart. It sends signals and electric currents between your heart and the pulse generator. Some people need multiple leads with their ICD.
Path to improved health
Why might I need an ICD?
It is possible for your heartbeat to become irregular. This is called an arrhythmia. There are many different types of arrhythmias. Treatment for arrhythmia depends on what kind you have. An ICD is one form of treatment. You may need an ICD if you have or are at high risk of a life-threatening ventricular arrhythmia. Examples include ventricular tachycardia and ventricular fibrillation. Having a previous heart attack, heart disease, or cardiac arrest are other reasons you may need an ICD.
Ventricular tachycardia is when the bottom chambers of your heart (the ventricles) beat too fast. When this happens, your heart has a hard time pumping blood. As a result, your body and brain don’t get enough blood, which is life threatening.
Ventricular fibrillation is when the bottom chambers of your heart (the ventricles) beat too fast and unevenly. The heart flutters, and little or no blood is pumped to your body and brain. Someone who has this type of arrhythmia is at risk of passing out. Treatment is required within minutes in order to prevent death.
How is an ICD implanted?
Typically, a doctor or surgeon implants an ICD during minor surgery. The pulse generator is placed either under your collarbone on the left or right side of your chest, or in your abdomen (stomach area). It can go in a “pocket” under your skin or in a muscle. The doctor inserts one end of the lead into a vein that goes to your heart. They move the wire through the vein until it reaches the heart. The other end of the wire gets attached to the pulse generator.
Once it is implanted, the doctor programs and tests the ICD in order to treat your specific heart rhythm problem. The whole process requires a short hospital stay.
How does an ICD work?
The ICD’s job is to quickly recognize and stop problems. It does this by keeping track of your heart rhythm at all times. If your heartbeat becomes irregular, the ICD delivers the treatment. Your doctor can program the ICD to do several things.
- Pacing: For mild ventricular tachycardia, the ICD can deliver several pacing signals in a row. These signals cause your heart to return to a normal rhythm.
- Cardioversion: This is used if pacing doesn’t work. Cardioversion sends a mild shock to your heart to stop the fast heartbeat.
- Defibrillation: For ventricular fibrillation, the ICD sends a stronger shock. This can stop the fast rhythm and help the heartbeat go back to normal.
- Pacemaker: The ICD also can detect when your heart beats too slow. It can act like a pacemaker and bring your heart rate up to normal.
What does treatment with an ICD feel like?
When the ICD delivers pacing or acts as a pacemaker, you may not feel anything. This is because little energy is used. Some people feel fluttering in their chest, but it doesn’t cause pain or discomfort. Cardioversion is stronger than pacing. It can feel like a thump in your chest.
Defibrillation is the strongest treatment. Most people say it feels like being kicked in the chest. It often happens all of a sudden, but lasts less than a second. It can make you upset or anxious afterward. However, it’s important to remember that it probably saved your life.
Things to consider
An ICD does not cure an arrhythmia or heart disease. It manages your condition(s) and helps prevent cardiac arrest and death. Along with the ICD, your doctor may prescribe medicine. Follow all instructions and tell your doctor what other medicines you take.
Ask your doctor for an ICD wallet ID card. It is important that you carry this at all times. You will need this when you travel and in case of an emergency.
How will an ICD affect my lifestyle?
After you get an ICD, you will need to limit activity. This allows your body to adjust and heal properly. You can slowly go back to your regular lifestyle. Ask your doctor when it is safe to drive a car again. It will vary based on your condition and the local laws. In general, you can expect to be back to normal after a month.
You need to stay away from machines that could interfere with your ICD. Do not work near strong magnetic or electrical fields. The ICD is safe around most home power tools and electric appliances, including microwave ovens. However, make sure that all electric items are properly grounded and in good repair. Your doctor can help you understand what to avoid when you have an ICD. Machines, devices, or procedures that may cause interference include:
- security metal detectors
- power-generating equipment
- some power tools and electronic devices
- electric fences and transformer boxes
- electronic mattresses or pillows
- anti-theft systems
- cell phones
- magnetic resonance imaging (MRI)
- therapeutic radiation
- electrolysis (electric hair removal).
When to see a doctor
Your doctor should test your ICD at regular checkups. Its generator battery can last five to seven years. It can be replaced in outpatient surgery.
Getting an ICD may cause new emotions or depression. Talk to your family and a doctor if this happens to you. The doctor can recommend counseling or a support group.
Questions to ask your doctor
- Once I have an ICD will I always need it?
- How do I care for my wound after ICD surgery?
- How long after getting an ICD can I return to my normal activities?
- Can I have drive?
- Can I have sex?
- Can I play video games and use electronics?
- Will I know when a shock is coming?
- How do I know if my ICD is working or not?
Copyright © American Academy of Family Physicians
This information provides a general overview and may not apply to everyone. Talk to your family doctor to find out if this information applies to you and to get more information on this subject.