Frequently Asked Questions: Implantable Cardiac Defibrillator (ICD)

What is an implantable cardiac defibrillator?

An implantable cardiac defibrillator (ICD, or implantable cardioverter defibrillator) is an internal shocking device that provides immediate therapy to a life-threatening arrhythmia (heart beating too quickly) via a jolt of electricity. It can also act as a pacemaker if the heart is beating too slow.

Why might a person need one?

Numerous underlying heart conditions that can cause a weakening of the heart muscle can predispose an individual to develop or be at risk to develop life threatening ventricular arrhythmias. For adults, the most common condition is coronary artery disease leading to ischemic cardiomyopathy (where heart can’t pump enough blood to the rest of the body).

How does it work?

The implantable device continuously monitors heart rhythm and is programmed to deliver “pacing impulses” to restore its natural rhythm, which would avoid the need for a shock. If pacing is unsuccessful, it will deliver a shock to the heart.

Where does it get implanted?

The device is implanted under the superficial skin tissues in a preformed pocket in the left pectoral area. The leads are inserted into the large subclavian vein and threaded into the heart and then secured within the right heart chambers.

How does my doctor determine if I need an ICD?

Through a comprehensive evaluation that includes: history and physical exam, echocardiography (using sound waves to see the heart), electrocardiography (measures heart’s electrical impulses) and at times may require a nuclear stress test, cardiac catheterization and cardiac MRI.

How big is it?

It’s slightly smaller and thinner than a deck of cards.

How much is the ICD going to protrude from my chest?

It depends on the person. It also depends on the type of implant that you receive. Some of the implants are very small and some are a little bigger. If you’re thin, it generally will protrude. If you have a little more bulk it won’t be so obvious. The device can be implanted under the breast muscle, which would prevent it from being seen. Speak to your physician about options for your implant location.

What does a shock feel like?

Some people say it feels like being hit in the back with a baseball bat. Others say it feels like being kicked by a horse. It differs with everyone and only lasts for a second. Most people feel it more in the back than in the front.

What should I do after a shock?

First thing, you should sit down. It’s possible that you could pass out from the shock, and you want to make sure you don’t fall and/or hit your head. Call your doctor’s office and let them know you received a shock. If you received multiple shocks, you should go straight to the emergency room. Interrogation — using a device connected to your phone line to remotely monitor your device — will let your doctor know what happened.

Will an ICD change the quality of my life?

No. Your life will only change if you allow it to. The ICD won’t hinder you or the activities that you do.

Can I still work with an ICD?

That depends on what you do for a living. Most people with an ICD are able to continue working. Speak with your doctor about your occupation.

Am I able to drive a car?

Every person is different. If you pass out from a shock, you won’t be allowed to drive for six months. The rules vary from state to state. Speak with your doctor or call your local DMV.

Are there any risks to having an ICD?

Yes. Risks are rare, but include: bleeding, infection, swelling, blood leaking through the heart valve when the lead was placed, collapsed lung, stroke and blood clot. The device is also manmade and therefore can have a malfunction, such as not correcting an irregular heart rhythm. If the ICD malfunctions, it may either be reprogrammed or replaced.

Will people be afraid to touch me?

No. Even if someone does touch you when you are shocked, it won’t hurt the other person. They may feel a tingle, like getting a static shock from the rug.

I feel scared and depressed. Is this normal?

Absolutely. In the beginning, many people worry about the shock and if and when it will happen. Some people don’t even know they’re in arrhythmia when the device fires. However, other people have had an ICD for years and have never experienced a shock. Joining a support group and meeting others who share your fears can help you feel better. And if you’re having anxiety, you can speak to your doctor about anti-anxiety medication.

What factors can have a negative effect on my ICD?

Not getting proper device follow-up (generally a twice a year clinic visit plus interim home-monitoring). With regular device follow-up, we can identify potential device system issues and can correct prior to you experiencing negative effects.

Not being compliant with prescribed medications, diet and fluid restrictions, and individual activity restrictions.

Some in-hospital procedures, such as surgery (the ICD needs to be disabled during surgery) and MRI (generally not recommended but can be performed in certain situations).

Anything that causes electromagnetic frequencies, such as large generators, transformers, large machinery, airport security, store anti-theft surveillance devices. Generally, you just need to maintain a certain distance to avoid interaction.

Will an airport security scanner affect it?

You shouldn’t go through the metal detector or get scanned with a handheld wand. Tell security you have an ICD, ask to be patted down and have your ICD card handy.

Why do I need an emergency plan?

It’s important to have an action plan in case there are changes in your health condition. You should be provided with our contact information for regular business hours and after hours emergencies or concerns. You should be instructed what to do if you get a shock or multiple shocks from your device, or if you are experiencing new symptoms, such as lightheadedness or syncope (loss of consciencousness). Ask your doctor to discuss your emergency plan with you.

Is peer support available?

Yes. The University of Michigan Cardiovascular Center has a quarterly adult support group where device patients and their families and friends attend a luncheon that includes peer interaction and education. Groups are led by device nurses and social workers. We also hold an annual ICD support program for children, teens, young adults and their families.  Facebook group: search for Young ICD Connection.

What’s the difference between an electrophysiologist (EP) and a cardiologist?

The cardiologist takes care of your heart and the electrophysiologist takes care of the electrical system within your heart.

How can I learn more about ICDs?

Your cardiologist or electrophysiologist (a cardiologist with specialized training for abnormal heart rhythms) will have printed and electronic educational materials, or you can find information at the University of Michigan Cardiovascular Center’s Mardigian Wellness Center. The Heart Rhythm Society is also a good resource:

Make an Appointment

The Arrhythmia Program at the University of Michigan has been a national and international leader in the treatment of arrhythmias for more than 30 years. To schedule an appointment to discuss your heart arrhythmia or other cardiovascular condition, call us at 888-287-1082 or visit our Make a Cardiovascular Appointment page, where you may fill out a Patient Appointment Request Form and view other details about making an appointment.