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Implantable Cardioverter Defibrillator

What is an implantable cardioverter defibrillator?

An implantable cardioverter defibrillator (ICD) is a small device that monitors your heart rate and rhythm. It is commonly placed inside your chest or abdomen. It may be used if you have an arrhythmia. An arrhythmia is an irregular heart rate or a heart rate that is too fast or too slow. Some arrhythmias may cause your heart to suddenly stop beating. An ICD can give a shock to your heart to make it start beating again. It can also make your heart beat faster or slower.

You may need an ICD if you have the following:
  • Congestive heart failure, coronary artery disease, a previous heart attack, or another condition that weakens your heart

  • A fast or slow heart rate

  • An irregular heart rate, which makes it hard for your heart to pump blood

What do I need to know about an ICD?

An ICD is made up of a generator, a programmer, and leads (wires). Your caregiver will place the generator and leads inside your chest or abdomen during surgery. The generator has a metal shell with a battery and a small computer. The computer will monitor your heart rate and rhythm. One end of the lead will attach to the inside of your heart. The other end of the lead will be connected to the generator. The generator sends information about your heart to the programmer. Your caregiver will adjust the programmer to regulate your heart rate.

What does an ICD feel like?

You will be able to see and feel the outline of the ICD through your skin. You will not feel it monitor your heart. If the ICD detects an abnormal heart rhythm, it may give your heart a shock. This may feel like someone has hit you, or you may feel a thump in the chest. If someone is touching you when you get a shock, they may feel a tingling feeling.

What are the risks of an ICD?

You may bleed more than usual or get a blood clot after surgery. This could become life-threatening. You may get an infection after surgery. The leads could poke a hole in your heart, lung, or vein. The leads may also cause arrhythmias when they are placed. Blood may collect in the pocket where the generator is placed and cause pain or an infection. The leads may disconnect or break, and you may need another surgery. If you do not get an ICD, your heart problems could get worse and become life-threatening.

Where can I find support or more information?

  • American Heart Association
    7272 Greenville Avenue
    Dallas , TX 75231-4596
    Phone: 1- 800 - 242-8721
    Web Address:

When should I contact my caregiver?

Contact your caregiver if:

  • You have a fever.

  • You feel 1 or more shocks from your ICD and feel fine afterwards.

  • Your feet or ankles swell.

  • The area around your ICD is painful or tender after surgery.

  • The skin around your stitches or staples is red, swollen, or draining pus or fluid.

  • You have chills, a cough, and feel weak or achy.

  • You are sad or anxious and find it hard to do your usual activities.

  • You have questions or concerns about your condition or care.

When should I seek immediate care?

Seek care immediately or call 911 if:

  • Your stitches or staples come apart.

  • Blood soaks through your bandage.

  • You feel more than 3 shocks in a row from your ICD.

  • You become weak, dizzy, or faint.

  • You feel your heart skip beats or beat very fast or slow, but you do not feel a shock from your ICD.

  • You have chest pain that does not go away with rest or medicine.

Care Agreement

You have the right to help plan your care. Learn about your health condition and how it may be treated. Discuss treatment options with your caregivers to decide what care you want to receive. You always have the right to refuse treatment. The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

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