cardioverter-defibrillator (ICD) helps protect you against dangerous heart
rhythms. It's important to know how this device works and how to keep it
working right. Learning a few important facts about ICDs can
help you get the best results from your device.
Avoid strong magnetic and electrical fields.
These can keep your device from working right. Most office
equipment and home appliances are safe to use. Learn which things you should
use with caution and which you should stay away from.
Know what to do when you get a shock from your ICD.
Be sure that
any doctor, dentist, or other health professional you see knows that you have an
Always carry a card in your wallet that tells
what kind of device you have. Wear medical alert jewelry that says you have an
Have your ICD checked regularly to
make sure it's working right.
It's common to be anxious that the ICD might shock you. But you can take steps to think positively and worry less about living with an ICD.
cardioverter-defibrillator (ICD) is a small electrical device that can stop a possibly deadly heart rhythm (arrhythmia).
An ICD is
implanted under the skin in your chest. A wire threaded
through a large vein connects the device to your heart. It is always
checking your heart rate and rhythm. If the ICD detects a
life-threatening rapid heart rhythm, it tries to slow the rhythm to get it back to normal. If the dangerous rhythm doesn't stop, the ICD sends an electrical shock to the heart to
restore a normal rhythm. The device then goes back to its watchful mode.
If your heart is beating too slowly, the ICD acts as a pacemaker, sending
mild electrical pulses to bring your heart rate back up to normal.
Test Your Knowledge
If your heart is beating too fast, an ICD sends a
strong shock to your heart.
To be sure that your device is
working right, you will need to have it checked regularly. ICDs can stop working because of loose or broken wires or other problems. Your doctor
will also make sure your ICD settings are right for what your body
You may need to go to your doctor's office, or you may be
able to get the device checked over the phone or the Internet.
ICDs run on batteries. In most cases, ICD
batteries last 5 to 15 years. When it's time to replace the
battery, you'll need another surgery, although it will be easier than the
surgery you had to place the device. The surgery is easier, because your doctor doesn't have to replace the leads that go to your heart.
Test Your Knowledge
It's important to have your ICD checked
regularly to make sure it is working right.
When you have an ICD, it's important to avoid strong magnetic
and electrical fields. The lists below show electrical and magnetic sources and
how they may affect your ICD. For best results, follow these
guidelines. These safety tips also apply to devices that combine an ICD and a pacemaker. If you have questions, check with your doctor.
Following safety tips
Safety guidelines for pacemakers and ICDs
Stay away from:
CB or ham
High-voltage power lines. Stay at least
25 ft (7.5 m)
An MRI uses a magnetic field and pulses of radio wave energy to make pictures
of organs and structures inside the body.
Use with caution:
Do not carry a cell phone in a
pocket directly over the pacemaker or ICD.
Hold the phone to the
ear on the side away from your device.
Keep a phone at least
6 in. (15 cm) away from the
pacemaker or ICD.
MP3 player headphones:
Do not keep headphones in a chest
pocket. Do not drape headphones over your chest.
Keep the following devices at least
12 in. (30.5 cm) away from the
pacemaker or ICD:
Battery-powered cordless power tools
Magnetic wands used at
Radio transmitters (including
those used in toys)
Safe to use:
Kitchen and bathroom equipment:
Bathroom appliances (electric
razors, curling irons, and hair dryers)
Kitchen appliances (such as
toasters, blenders, electric can openers, and
Microwave, gas, and electric ovens
Other household items:
Electric tools (such as drills and
Lawn and garden equipment (such as mowers and leaf
Heating pads and electric blankets
machines and dryers
Phones (land-line phones including cordless
TVs, VCRs, CD players, DVD
What to do if you get a shock
If you get a shock from your ICD, follow the plan you set up with your doctor. In general, your plan depends on how you feel after you get a shock and how many times you get a shock.
After one shock:
Call 911 or other emergency services immediately if you feel bad or have symptoms like chest pain.
Call your doctor soon if you feel fine right away. Your doctor may want to talk about the shock and schedule a follow-up visit.
After a second shock within 24 hours:
Call your doctor right away, even if you feel fine right away.
After a shock, do some breathing exercises. They may help you relax.
Sit or lie in a comfortable position.
Put one hand on your belly just below your ribs and the other hand on your chest.
Take a deep breath in through your nose, and let your belly push your hand out. Your chest should not move.
Breathe out through pursed lips as if you were whistling. Feel the hand on your belly go in, and use it to push all the air out.
Breathe in and out like this until you feel more relaxed.
Having medical tests and procedures
Most medical tests and procedures won't affect your ICD,
except for MRI, which uses strong magnets. To be safe:
Let your doctors, dentists, and other health
professionals know that you have an ICD before you have any test,
procedure, or surgery.
Have your dentist talk to your doctor
before you have any dental work or surgery.
If you need physical
therapy, have the therapist contact your doctor before using ultrasound, heat
therapy, or electrical stimulation.
You can travel safely with a cardiac device. But you'll want to be prepared before you go.
Bring a list of the names and phone numbers of your doctors.
Bring your cardiac device identification card with you.
Know what to do when going through airport security.
If you have an arrhythmia or an ICD that makes it dangerous for you to drive, your doctor might suggest that you stop driving, at least for a short time. You probably don't have to stop or limit driving if your arrhythmia doesn't cause bad symptoms.
For more information, see Heart Rhythm Problems and Driving.
Letting others know
Carry an ICD identification card with you at
all times. The card should include manufacturer information and the model
number. Your doctor can give you an ID card.
Wear medical alert jewelry stating that you have an
ICD. You can buy this at most drugstores.
If you take heart rhythm medicines, take them as
prescribed. The medicines work with your ICD to help your heart
keep a steady rhythm.
If you think you have an infection near your device, call your doctor right away. Signs of an infection include:
Changes in the skin around your device, such as swelling, warmth, redness, and pain.
An unexplained fever.
Ask your doctor what sort of activity and intensity is safe for you. ICDs are set to shock at a specific heart rate.
So your target heart rate during exercise will probably be at least 10 to 15
beats below the ICD discharge heart rate.
You doctor can help you learn how to use a rating of perceived exertion (RPE) as a way to tell how hard you are exercising. This can help you keep your heart rate at a safe level during exercise.
Stop exercising and call your doctor if you have:
Pressure or pain in your chest, neck, arm,
jaw, or shoulder.
Dizziness, lightheadedness, or
Unusual shortness of breath or tiredness.
A heartbeat that feels unusual for you: too fast, too
slow, or skipping a beat.
Other symptoms that cause you
A shock from your ICD.
Most people who have an ICD (implantable cardioverter-defibrillator) can have an active sex life. If your doctor says that you can exercise and be active, then it's probably safe for you to have sex.
After you get the device implanted, you'll let your chest heal for a short time before resuming sex.
What if I get shocked? Many people with ICDs worry that their ICD might shock them during sex. The risk of getting a shock during sex seems to be the same as during any other similar level of exercise. If you get a shock during sex, you will follow your plan about when to call your doctor.
Will my partner get shocked? Some people worry that if they get shocked during sex, their partner might be hurt. But your partner will not be shocked or feel any pain if you get shocked.
Coping with worry about ICD shocks
You may feel nervous about living with an ICD, and you may worry about getting shocked.
The shock can be uncomfortable. It may feel like you are being kicked in the chest. For many people, getting a shock can cause anxiety and depression.
It's common to be worried about living with an ICD. After all, you don't know when a shock might occur, and a shock could be a reminder that your heart is not as healthy as it could be. But if you take a few simple steps, you can feel better about having an ICD.
Try to replace a negative thought about the ICD with a positive one. For example: When you start to worry about getting a shock, remind yourself that the ICD is there to help save your life. Or try to focus on the positive things in your life, such as loving relationships, pleasant activities, or good friends. For more information, see:
Talk to your doctor about making an action plan for what to do if you get shocked.
Don't make changes in what you do. You may want to avoid an action because you think it caused the shock. But a shock can occur at any time, and you can't prevent shocks by your actions alone. Don't stop doing things you enjoy to try to avoid a shock.
Planning for the future
As you plan for your future and your end of life, include plans for your ICD. You can make the decision to turn off your ICD as part of the medical treatment you want at the end of life. You can put this information in your advance directive.
Test Your Knowledge
It's safe to use a cell phone, but don't keep it in a
pocket directly over your ICD.
Lampert R, et al. (2010). HRS Expert Consensus Statement on the Management of Cardiovascular Implantable Electronic Devices (CIEDs) in patients nearing end of life or requesting withdrawal of therapy. Heart Rhythm, 7(7): 1008–1026.
Sears SF, et al. (2005). How to respond to an implantable cardioverter-defibrillator shock. Circulation, 111(23): e380–e382.
Vasquez LD, et al. (2010). Sexual health for patients with an implantable cardioverter-defibrillator. Circulation, 122(13): e465–e467.
Wilkoff BL, et al. (2008). HRS/EHRA expert consensus on the monitoring of cardiovascular implantable electronic devices (CIEDS): Description of techniques, indications, personnel, frequency, and ethical considerations. Heart Rhythm, 5(6): 907–925. Available online:
Primary Medical Reviewer
Rakesh K. Pai, MD, FACC - Cardiology, Electrophysiology
Specialist Medical Reviewer
Stephen Fort, MD, MRCP, FRCPC - Interventional Cardiology
How this information was developed to help you make better health decisions.