Defibrillator (ICD)

Implantable Cardioverter-Defibrillator (ICD)

is a small electronic device that is implanted into your body. It is designed to treat life-threatening rapid heart rhythms.

ICD automatically detects and treat life-threatening rapid, too fast heart rhythms, called tachycardias. The ICD monitors your heart rhythm (the speed and pattern of your heartbeat) at all times. if it senses a dangerously fast heart rhythm, the ICD delivers electrical impulses and/or shocks to restore a normal heart rhythm.

You may be recommended an ICD if you have had cardiac arrest or if you have a heart condition that could cause cardiac arrest. During cardiac arrest, the heart stops pumping blood. If not treated, cardiac arrest leads to death.

An ICD cannot prevent your heart from beating too fast. It is not a cure for your heart rhythm problem. But it can safe your life by quickly bringing a dangerously fast rhythm under control. Having an ICD may give you more freedom to do the activities you enjoy.

An ICD is used for people who have one or more of these health conditions:

  • A history of ventricular tachycardia, ventricular fibrillation, or cardiac arrest
  • An inherited defect of the heart’s electrical system that can cause dangerous tachycardias
  • An increased risk of sudden cardiac death because of a history of heart attack, heart failure, or a weakened heart.


The Parts of an ICD

An ICD has two main parts: a pulse generator and one or more leads.

Pulse generator is a small, lightweight metal case containing a battery and circuitry which produces electrical impulses and/or shocks and controls the timing at which these are delivered to the heart.

A lead is an insulated, flexible wire that is placed in your heart. The lead carries electrical energy from the ICD to the heart. It also relays information about your heart’s electrical activity back to the device.  An ICD can have one, two, or three leads.

Implanting your ICD

Implanting an ICD is a minor surgical procedure that requires only local anesthesia. It is usually done in an electrophysiology (EP) lab or an operation room.


Preparation for the Procedure

  • Do not eat or drink anything for 6 to 8 hours before the procedure. You may have small sips or water to take your medications.
  • You may be asked to stop some medications (such as aspirin) for 2 or 3 days before the procedure. Talk to your doctor about your medications when you schedule the procedure.
  • Bring a list of the names and dosages of all the medications you are taking.
  • Ask someone to drive you to and from hospital. You will not be permitted to drive home after the procedure, since you may be sedated.
  • Pack a small bag for your hospital stay. Take with you a robe, slippers, pajamas or nightgown, and toiletries.
  • Tell the doctor or nurse if you have had any allergic reactions to medications or x-ray dye (contrast), iodine or seafood, or if you have a history of bleeding problems.
  • An ICD can be placed near the right or left shoulder. If you prefer a particular side, let the doctor know.
  • Empty your bladder before the procedure starts.

What To Expect

The procedure usually takes 1 to 2 hours.

Most often, the pacemaker is implanted in the upper chest, near the right or left shoulder. Occasionally, it may be implanted under the skin in the abdomen.

A local anesthetic is injected to numb the area where the pacemaker will be inserted.

You will be given medications to help you relax and make you drowsy. You may be awake, or you may sleep through part of all of the procedure. The staff will be monitoring you at all times.  Be sure to let them know if you feel any pain or discomfort.

Is Implanting a Pacemaker Safe?

Implanting an ICD is a simple procedure with little risk. Possible complications include

bleeding at the incision or pocket site. Blood collects under the skin, resulting in local swelling and/or a bruise.

In rare cases, the procedure may lead to more serious complications, including damage to the heart and blood vessels, a punctured lung, infection, and blood clots. Death is very rare.

After the Procedure

It is normal to have some pain and stiffness around the incision site for a few days. You doctor will prescribe you pain medication. Don’t raise the arm on the side of the incision above shoulder level.

Most patients stay in hospital overnight; some will stay as extra day. Before you go home, you will be given instructions about caring for the incision, physical activity, and medications. When it is time to leave, have a relative or a friend to drive you home.

Recovering at Home

A few days after you leave the hospital, you will most likely be able to go back to your usual daily activities. However, it may take a few weeks before the incision is completely healed.

For a few weeks you may feel numbness or fullness in the area around the ICD, which is normal.

The First Few Weeks

  • Follow your doctor’s instructions regarding activity, exercise, and returning to work.
  • Keep the incision site completely dry for a week or so, to help prevent infection.
  • Do not lift anything heavier than 10 to 15 pounds. Also, avoid too much pushing, pulling, or twisting.
  • For about 2 weeks, do not raise the arm on the side  of the ICD above shoulder level.
  • Call your doctor if the incision site shows signs of infection (pain, redness, swelling), there is drainage from the incision, or you develop a temperature over 100° F.
  • Call your doctor if you have twitching chest muscles, hiccups that will not stop, or a swollen arm on the side of the incision.
  • Call your doctor if the symptoms you had before come back, or if you have dizziness, chest pain, or shortness of breath.
  • Ask your doctor or nurse  which medications you can keep taking and which ones you need to stop.
  • Tell any doctors and medical personnel you see that you have an ICD.

Follow–Up Visits

A typical follow-up visit takes about 30 minutes. You will have to check your ICD several times during the first year, and then once or twice a year after that.

Replacing the Battery

ICDs  are powered by long-lasing lithium batteries. In general, a battery lasts 4 to 7 years.

Since the battery is sealed inside the pulse generator, the entire pulse generator must be replaced when the battery wears out. In most cases, the original leads will not need to ne replaced.

ICD Identification Card.

You will receive a wallet card with information about your ICD, as well as your doctor’s name and phone number.


You must carry your card with you all the times! Show it to any health care provider you visit.
Also, because your ICD may set off security devices, you may need to show your card to security personnel.

If You Receive a Shock:

  • Stay calm and find a place to sit or lie down
  • Have someone stay with you throughout the event, if possible
  • Ask a friend or family member to phone for an ambulance in case you receive several shocks or are unconscious for more then a few moments.
  • If you receive a shock and do not fell well afterwards, have someone call your doctor
  • Follow your doctor’s or nurse’s directions on when to call after receiving a shock.
  • When you call, you may be asked:
    • How did you feel right after the shock?
    • What were you doing right before the shock?
    • What symptoms did you have?
  • It is possible you could feel symptoms of rapid heart rhythm and not receive a therapy. This depends on how your ICD is programmed. If your symptoms are severe or do not go away and you do not feel a shock, call your doctor (or 9-1-1) right away.
  • Anyone touching you while the ICD delivers a shock might feel the muscles of your chest and upper arms tighten. The shock will not harm the person touching you, but he or she may feel a tingle.

Call Your Doctor If:

  • Within 24 hours of receiving a shock
  • If you receive 3 or more shocks in a row
  • If your symptoms of a rapid heart rhythm last longer than a couple of minutes
  • Before having medical or dental procedures, especially if they involve surgery
  • When you have questions about your ICD, medications, or activities
  • When you plan to travel or move

Avoid Interference!

Things that use magnets or electricity have magnetic fields around them. These fields are usually weak and will not affect your ICD. However, strong magnetic fields can interfere with your ICD and may temporarily affect the way it works.

Safe Items:

Microwave ovens, toasters, blenders, and electric can openers; Radio, Televisions, CD/DVD players, pagers, remote controls, garage door openers; Hair dryers, and shavers ( avoid holding against the implant site); Refrigerators, washers, dryers, and electric stoves; Electric blankets and heating pads, personal computers, fax machines, printers, and copy machines.

Items that can be used but should remain at least 12 inches away from the implant site:

Battery-powered, cordless power tools such as screwdrivers and drills; Shop tools, such as corded drills and table saws; Lawn mowers, leaf blowers; Slot machines, stereo speakers


Large generators, electric motors, arc welders, and other large industrial equipment; Radio transmitters, high-voltage power lines; Magnetic therapy products, such as mattress pads, pillows, and massagers; Maintaining or repairing any electrical or gasoline-powered appliances; Leaning over the open hood of a running car.

If you have questions about the safety of a particular appliance, tool, or activity, check with your doctor or curse or call the company that makes the pacemaker.

Medical Procedures

Some procedures produce strong magnetic fields and should usually be avoided ( talk to your doctor first). These include:

Magnetic resonance imaging (MRI), electrocautery, diathermy, lithotripsy, transcutaneous electrical nerve stimulation (TENS), and radiation therapy.


Always tell any doctors or other medical personnel that you have a ICD.

Cell Phones

A cell phone can affect your ICD if the phone it held to close to it.  This effect is temporary. You can move the phone away form the pacemaker and the ICD will work properly again.

When using a cell phone, hold it to the ear farthest from your ICD. Do not carry the phone in a breast pocket or on a belt within 6 inches of where the ICD is implanted.

Security systems

You can walk though security gates, such as those at airports and stores. The system will not harm your ICD, buy it may detect the metal case around the pulse generator and set  off the alarm. If this happens, show your wallet card to the security personnel.

Hand-help security wands, such as those used at airports, may interfere with your ICD. Show your wallet card to security and ask to be hand searched instead of the hand-held wand.

At the entrance to stores and libraries, you may walk normally through anti-theft security gates, but do not stay near the theft detection equipment.