What is an implantable cardioverter-defibrillator?

Normally, an electrical signal in your heart starts each heartbeat, causing the heart muscle to squeeze (contract). This signal starts in the upper right chamber of the heart (the right atrium). The signal then follows normal pathways to the upper left atrium and to the lower chambers of the heart (the ventricles). When your heart cannot beat regularly because of a problem with the electrical signal or damage to your heart, you may need an ICD. Most ICDs can act as both a pacemaker and an ICD. ICDs can help heart conditions such as:

• Life-threatening heart rhythms, which may be caused by a heart attack, heart disease, or other health problems. An ICD can be life saving if you have a life-threatening heart rhythm or if your heart stops suddenly.
• A very slow, very fast, or irregular heart rhythm. A pacemaker can speed up a slow rhythm or control a very fast or irregular rhythm.
• Atrial fibrillation, which is a condition that causes the upper chambers of the heart (atria) to beat very fast and not in a normal pattern. A pacemaker can signal the lower chambers of your heart to beat if the upper chambers are not beating in a normal pattern.
• Heart failure, which means the heart is not pumping blood as well as it should. A pacemaker can help coordinate the electrical signals between the two lower chambers of your heart so that your heart pumps more effectively. This treatment is called cardiac resynchronization therapy (CRT). An ICD that can do cardiac resynchronization therapy is called CRT-D.

An implantable cardioverter defibrillator (ICD) is a small battery-powered device that helps your heart beat in a normal rhythm. The ICD device is placed under the skin in your chest or belly. You will be able to feel the device under your skin. It’s about the size of a large watch. The ICD is attached to wires that deliver electrical signals, or small electric shocks, to your heart. Your healthcare provider sets it to monitor your heart rhythm and send electrical signals to your heart, if needed. The electric signals cause your heart to beat in a regular pattern.

When your heart is beating normally, the ICD does nothing. If the ICD detects a heart rhythm that is too fast, too slow, or irregular, the device first tries to control the heart rhythm with low-level electric signals, like a pacemaker. If this doesn’t work, or the rhythm gets worse, the ICD sends a high-level shock to your heart. The electric shock changes the abnormal rhythm to a normal rhythm. You will feel the shock and it may be slightly painful.

Some devices can also monitor your blood temperature and breathing and adjust your heart rate when you are physically active.

How is an implantable cardioverter-defibrillator insertion done?

Before the procedure:

• Your healthcare provider will ask you to sign a consent form for the procedure. The consent form will state the reason you are having the procedure, what happens during the procedure, and what you may expect afterward.
• Tell your healthcare provider if you are allergic to any medicines.
• Tell your healthcare provider if you are taking any medicines, including nonprescription drugs, herbal remedies, or illegal drugs (if any).
• You will have a small tube (IV catheter) inserted into a vein in your hand or arm. This will allow medicine to be given directly into your blood and to give you fluids, if needed.

During the procedure:

• You may be given a sedative through your IV to help you to relax.
• You will be given medicine called anesthesia to keep you from feeling pain during the procedure. You may have:
  • Local anesthesia, which numbs the area where the procedure will be done.
  • General anesthesia, which relaxes your muscles and you will be asleep. A breathing tube is usually put in your throat when you have general anesthesia.
• The surgeon will use a large needle to insert the ICD leads into a large blood vessel in you upper chest and into the heart. The provider will use a type of X-ray to guide the leads to the right place in your heart.
• The surgeon will connect the leads to the ICD and test that the leads are in the right place.
• The surgeon will make a cut in the upper chest or abdomen to insert the ICD just under the skin.
• The cut will be stitched closed.

After the procedure:

• You may stay in the hospital for a few hours or several days to recover, depending on your condition.
• While you are in the hospital, you will be checked often by nursing staff.
• There will be a dressing on the ICD insertion site. The dressing will be checked and changed by your provider or the nursing staff as needed.
• Your provider may prescribe medicine to:
  • Treat pain
  • Treat or prevent an infection
  • Relax and widen blood vessels and allow blood to flow through them easier
  • Help prevent blood clots
  • Slow the heart rate and reduce the workload of the heart
  • Reduce fluid build-up and swelling in the body
• Your blood oxygen level may be monitored by a sensor that is attached to your finger or earlobe.
• A cardiac (heart) monitor will be used to keep track of your heart rate and rhythm.

What can I do to help?

• You will need to tell your healthcare team if you have new or worsening:
  • Chest pain or pressure, squeezing, or fullness in the center of your chest that lasts more than a few minutes, or goes away and comes back (may feel like indigestion or heartburn)
  • Pain or discomfort in one or both arms or shoulders, or in your back, neck, jaw, or stomach
  • Trouble breathing
  • Breaking out in a cold sweat for no known reason
  • Along with the previous symptoms, feeling very tired, faint, or sick to your stomach
  • Feeling like your heart is beating too fast, too slow, or skipping beats
  • Swelling of your legs, ankles, or feet
  • Signs of infection around your ICD insertion site. These include:
    • The area around your wound is more red or painful
    • The wound area is very warm to touch
    • You have blood, pus, or other fluid coming from your wound area
    • You have chills or muscle aches
• Ask questions about any medicine, treatment, or information that you do not understand.

How long will I be in the hospital?

How long you stay in the hospital depends on many factors. The average amount of time to stay in the hospital for an ICD procedure is 4 to 5 days.