Implantable Cardioverter Defibrillator (ICD)


What is an ICD?

An ICD (implantable cardioverter defibrillator) is an electronic device that constantly monitors your heart rhythm. When it detects a very fast, abnormal heart rhythm, it delivers energy to the heart muscle. This causes the heart to beat in a normal rhythm again.

Why is an ICD needed?

Ventricular tachycardia and ventricular fibrillation are two life-threatening heart rhythms that cause the heart to beat very fast. These conditions can be fatal if not treated immediately.

Your doctor has recommended that you receive an ICD because you have had at least one episode of these heart rhythms or are at high risk of developing these types of heart rhythms.

Who needs an ICD?

An ICD may be recommended for people who:

  • Had a prior episode of sudden cardiac arrest
  • Had a prior episode of ventricular fibrillation
  • Had at least one episode of ventricular tachycardia
  • Had a prior heart attack and have an increased risk for sudden cardiac arrest or sudden cardiac death
  • Have hypertrophic cardiomyopathy

Together, you and your doctor will determine if an ICD is the right treatment for you.

How does an ICD work?

The ICD monitors the heart rhythm, identifies abnormal heart rhythms and determines the appropriate therapy to return your heartbeat to a normal heart rhythm. Your doctor programs the ICD to include one or all of the following functions:

  • Anti-tachycardia pacing (ATP) – When your heart beats too fast, a series of small electrical impulses are delivered to the heart muscle to restore a normal heart rate and rhythm.
  • Cardioversion – A low energy shock is delivered at the same time as your heartbeat to restore a normal heart rhythm.
  • Defibrillation – When the heart is beating dangerously fast, a high-energy shock is delivered to the heart muscle to restore a normal rhythm.
  • Bradycardia pacing – When the heart beats too slow, small electrical impulses are sent to stimulate the heart muscle to maintain a suitable heart rate.

Types of ICDs

Is the ICD implant procedure safe?

A device implant is generally a very safe procedure. However, as with any invasive procedure, there are risks. Special precautions are taken to decrease your risks. Please discuss your specific concerns about the risks and benefits of the procedure with your doctor.

Where is the implant procedure performed?

In most cases, the implant procedure takes place in a special room in the Electrophysiology Lab. When the epicardial implant approach is used, the procedure takes place in a surgical suite.

Procedure Details

Before the Procedure

  • If you have diabetes, ask the scheduling nurse how to adjust your diabetes medication(s).
  • If you take an anticoagulant (“blood thinner”), such as Coumadin (warfarin), ask the scheduling nurse for specific guidelines about taking it on the day of the procedure.
  • Do not eat or drink anything after midnight the night before the procedure.
  • Continue to take all of your medications as prescribed on the day of the procedure, but take them with only small sips of water.
  • Do not bring valuables to the hospital.

You will receive an instruction sheet that describes how to prepare for the procedure. Here’s an overview of those instructions.

What time should I report for my procedure?

The day before your scheduled procedure, please call 800.223.2273 and ask for Pager Number 21215, the EP scheduling nurse. Please call between 3:00 p.m. and 5:00 p.m. to find out what time you should arrive.If your procedure is scheduled for a Monday, please call the Friday before.

If your procedure is scheduled after a holiday, please call the last business day before the holiday.

Please do not call the Cleveland Clinic Operator or the Admitting Office for information about your procedure. We will notify you if there are any changes to your schedule.

Should I take my medications?

If you take Coumadin, the results of your INR test (a blood test to evaluate the blood clotting) must be within a suitable range before the implant procedure can be performed. You will likely need to stop taking anticoagulant medications, including aspirin or warfarin (Coumadin), a few days before the procedure.

Your doctor may also ask you to stop taking other medications, such as those that control your heart rate.

Do not stop taking any of your medications without first consulting with your healthcare provider. Ask your doctor which medications you should stop taking and when to stop taking them.

If you have diabetes, ask the nurse how to adjust your diabetes medications or insulin.

Can I eat before the procedure?

Eat a normal meal the evening before your procedure. However, DO NOT eat, drink or chew anything after midnight the night before your procedure. This includes gum, mints, water, etc. If you must take medications, take them with small sips of water. When brushing your teeth, do not swallow any water.

What should I wear?

  • When getting ready, please do not wear makeup and remove nail polish.
  • Wear comfortable clothes when you come to the hospital. You will change into a hospital gown for the procedure.
  • Please leave all jewelry (including wedding rings), watches and valuables at home.
  • The clothing you are wearing that morning will be returned to the person who accompanies you.

What should I bring?

You will not need a robe or toiletries when you first arrive. You may pack these items and have a family member keep your bag until after the procedure.

Bring a one-day supply of your prescription medications. Do not take these medications without first asking your doctor or nurse.

You may bring guided imagery tapes or music and the appropriate player.

What happens before the procedure?

Before the procedure begins, a nurse will help you get ready. You will be given a hospital gown to change into. You may keep your clothes in a locker or you may give them to a family member.

You will lie on a bed and the nurse will start an intravenous (IV) line in a vein in your arm or hand. The IV is used to deliver medications and fluids during the procedure.

To prevent infection and to keep the device insertion site sterile:

  • You will receive an antibiotic through the IV at the beginning of the procedure.
  • One side of your chest will be shaved.
  • The area will be cleansed.
  • You will be covered from your neck to feet with sterile drapes.
  • A soft strap may be placed across your waist and arms to keep your hands from touching the sterile area.

Will I be awake?

A medication will be given through your IV to relax you and make you feel drowsy, but you will not be asleep during the procedure.

Monitors During the Procedure

Several monitors will be used during the procedure to constantly check things like your heart rhythm and blood pressure.

Defibrillator/pacemaker/cardioverter: Attached to one sticky patch placed on the center of your back and one on your chest. This allows the doctor and nurse to pace your heart rate if it is too slow, or deliver energy to your heart if the rate is too fast.

Electrocardiogram or EKG: Attached to several sticky electrode patches placed on your chest, as well as inside your heart. Provides a picture on the monitors of the electrical impulses traveling through the heart.

Blood pressure monitor: Connected to a blood pressure cuff on your arm. Checks your blood pressure throughout the procedure.

Oximeter monitor: Attached to a small clip placed on your finger. Checks the oxygen level of your blood.

Fluoroscopy: A large X-ray machine will be positioned above you to help the doctors see the leads on an X-ray screen during the procedure.

How is the device implanted?

The ICD is usually implanted using the endocardial (transvenous) approach. During the procedure, a local anesthetic (pain-relieving medication) is injected to numb the area.

Small incisions are made in the chest where the lead(s) and device are inserted. The lead is inserted through the incision and into a vein, then guided to the heart with the aid of the fluoroscopy machine. The tip of the lead is attached to the heart muscle, while the other end is attached to the pulse generator. The generator is placed in a pocket created under the skin in the upper chest.

When the endocardial approach is used, the hospital recovery time is generally 24 hours.

Endocardial (transvenous) approach

Epicardial (surgical) approach

In rare cases when the endocardial approach cannot be used, the epicardial (surgical) approach is used. With this approach, you are put to sleep with general anesthesia. The generator is placed in a pocket created under the skin in the lower abdomen.

The hospital recovery time for this approach is generally 3 to 5 days, although minimally invasive techniques may be used that can result in a shorter hospital stay and quicker recovery time.

Your doctor will determine which is the best implant procedure approach for you.

How are the leads tested?

After the leads are in place, they are tested to make sure they are in the right place and working properly. This lead function test is called “pacing.” During the test, small amounts of energy are sent through the leads into the heart muscle. This energy causes the heart to contract. You will be asleep for several minutes during the lead function test.

Once the leads have been tested, the doctor will connect them to the device. The rate and settings of your device are determined by your doctor. After the implant procedure, the doctor uses an external device (programmer) to make the final device settings.

What will I feel?

With the endocardial approach: You will feel a burning or pinching sensation when the doctor injects the local numbing medication. Then, the area will become numb. You may feel a pulling sensation as the doctor makes a pocket in the tissue under your skin for the device. Please tell your doctor what symptoms you are feeling. You should not feel pain. If you do, tell your nurse right away.

How long does the procedure last?

The device implant procedure may last from 2 to 4 hours.


  • Have someone available to drive you home after the procedure.
  • Your doctor will discuss your medications, home-going instructions and follow-up schedule.

Recovery and Outlook

Will I have to stay in the hospital?

Yes. You will be admitted to the hospital and stay overnight after the procedure. You will probably be able to go home the day after your device was implanted, unless the epicardial approach was used during the procedure.

What should I expect during my recovery?

A special monitor, called a telemetry monitor, will continually monitor your heart rhythm. The telemetry monitor consists of a small box connected by wires to your chest with sticky electrode patches. The nurses can see information about your heart’s rhythm on several monitors in the nursing unit.

You will also have a holter monitor, which is a small recorder, attached to your chest with sticky electrode patches. The holter monitor records your heart rhythm for 12 hours to make sure the device is working properly.

What tests will be done after the procedure?

A chest X-ray will be done after the device implant procedure to check your lungs as well as the position of the device and lead(s). The monitor will be removed before you leave the hospital and your doctor will get the results. You will then go to the Device Clinic.

What happens at the Device Clinic?

You will sit in a reclining chair. Electrode patches will be placed on your chest and connected via wires to a computer. A nurse will place a small device called a programmer directly over the device. The programmer allows the nurse to change the device settings and to check the device and lead function. You may feel your heart beat faster or slower. Although this is normal, please tell the nurse what symptoms you are experiencing.T

he results of the device check are reported to your doctor, who then determines the appropriate settings for the device. The holter monitor results are also reviewed.

You’ll also review your home-going instructions, including incision care, activity guidelines, and follow-up schedule.

An echocardiogram may be performed as part of the Device Clinic evaluation or may be performed at your next follow-up appointment.

How will I feel?

You may feel discomfort at the device implant site during the first 48 hours after the procedure. The doctor will tell you what medications you can take for pain relief. Please tell your doctor or nurse if your symptoms are prolonged or severe.

What instructions will I receive before I leave the hospital?

Your doctor will discuss the results of the procedure and answer any questions you have. Be sure to ask the doctor if you should continue taking your previous medications.

You will receive specific instructions about how to care for yourself after the procedure, including medication guidelines, wound care, activity guidelines, device care, and maintenance and a follow-up schedule. Also refer to the handout, “ICD Discharge Instructions.”

ID Card

You will receive a temporary ID card that tells you what type of device and leads you to have, the device manufacturer, the date of the device implant and the doctor’s name who implanted the device.

Within 3 months, you will receive a permanent ID card from the device company. It is important to carry this card at all times in case you need medical attention.

Will I be able to drive myself home after the procedure?

No. For your safety, a responsible adult must drive you home. We request that your ride be ready to take you home by 10:00 a.m. on the morning of your discharge day.

Ask your doctor when you can start driving again.

When should I follow-up?

A follow-up appointment to check your ICD will be scheduled within 6 weeks after the device implant procedure. The appointment will be scheduled automatically and you will receive an appointment notice in the mail.

The ICD check is performed at the Device Clinic and takes about 15 to 30 minutes. The programmer will be placed over the device to retrieve device settings, measure battery voltage and collect information from the device about any fast heart rhythms and/or therapies you received. The leads will also be tested.

This first follow-up appointment is critical because adjustments will be made that will prolong the life of your device. This appointment is for a device check with the electrophysiology nurse. If you need to see your doctor for follow-up care, you will need to schedule a separate appointment.

How long does the ICD last?

Your ICD can last 3 to 6 years. By keeping your follow-up appointments in the Device Clinic, your healthcare team can monitor the function of your device and anticipate when it needs to be changed.

Managing your Condition

ICD therapy is only one part of a comprehensive treatment program. It is also important for you to take your medications, make changes to your diet, live a healthy lifestyle, keep your follow-up appointments and be an active member of your treatment team.


Doctors Who Treat

Doctors vary in quality due to differences in training and experience; hospitals differ in the number of services available. The more complex your medical problem, the greater these differences in quality become and the more they matter.

Clearly, the doctor and hospital that you choose for complex, specialized medical care will have a direct impact on how well you do. To help you make this choice, please review our Miller Family Heart, Vascular & Thoracic Institute Outcomes.

Cleveland Clinic Heart, Vascular & Thoracic Institute Cardiologists and Surgeons

Choosing a doctor to treat your abnormal heart rhythm depends on where you are in your diagnosis and treatment. The following Heart, Vascular & Thoracic Institute Sections and Departments treat patients with Arrhythmias:

  • Section of Electrophysiology and Pacing: cardiology evaluation for medical management or electrophysiology procedures or devices - Call Cardiology Appointments at toll-free 800.223.2273, extension 4-6697 or request an appointment online.
  • Department of Thoracic and Cardiovascular Surgery: surgery evaluation for surgical treatment for atrial fibrillation, epicardial lead placement, and in some cases if necessary, lead and device implantation and removal. For more information, please contact us.
  • You may also use our MyConsult second opinion consultation using the Internet.

The Heart, Vascular & Thoracic Institute also has specialized centers to treat certain populations of patients:

For younger patients with abnormal heart rhythms:

See About Us to learn more about the Sydell and Arnold Miller Family Heart, Vascular & Thoracic Institute.


If you need more information, click here to contact us, chat online with a nurse or call the Miller Family Heart, Vascular & Thoracic Institute Resource & Information Nurse at 216.445.9288 or toll-free at 866.289.6911. We would be happy to help you.

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*This information is about testing and procedures and may include instructions specific to Cleveland Clinic. Please consult your physician for information pertaining to your testing.

Last reviewed by a Cleveland Clinic medical professional on 07/18/2019.

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