1) The pulse generator is a smooth, lightweight, metal case that contains a battery and small computer. It continuously checks your heart's electrical signals. The memory in the pulse generator stores information about your heart's activity as well as the status of the ICD battery.

2) The leads are insulated, flexible wires which are positioned in the heart and are connected to the pulse generator.

There are several different ICDs. You may receive a one, two or three lead system. Your electrophysiologist will discuss your treatment plan with you prior to the procedure and review the lead system that will best meet your needs.

When is an Implantable Cardioverter Defibrillator (ICD) indicated?

Studies have shown that there are people who are at risk for extremely fast heart rhythms. In general, patients with a heart muscle that has been damaged and is not able to pump effectively are at higher risk for rapid heart rhythms. The damage may be due to a heart attack, or some other disease process. There are also rare genetic conditions that may make a person at risk for life threatening rhythms.

Some patients have already been diagnosed with these fast rhythms and have experienced a near death experience. Others may have an Electrophysiology Study to determine if the patient is prone to developing fast rhythms. Recent studies have shown that some cardiac diseases increase the risk of developing fast rhythms. Your cardiologist may recommend an ICD as prophylactic treatment in case you have a fast rhythm.

An ICD is designed to continuously monitor your heart rhythm. If a dangerously fast heart rhythm is detected, the device will immediately treat the rhythm and deliver therapy to return your heart to a normal rhythm. Treatment may include either rapid pacing of your heart to break the rhythm, or a shock to reset the heart's electrical system.

In addition, most ICDs contain pacemakers. They may be programmed to pace your heart on a regular basis or they may only provide pacing if your heart rate slows dramatically. Your electrophysiologist will determine the best settings for your clinical needs.

What happens during implantation of an Implantable Cardioverter Defibrillator (ICD)?

Most ICDs are implanted in the cardiovascular lab using a local anesthetic and medication to help you relax. Occasionally, a patient may require general anesthesia if their medical condition warrants. The decision regarding using anesthesia will be made by your electrophysiologist. For uncomplicated implants, the patient generally stays in the hospital overnight and goes home the day after the procedure.

Patients will have an incision approximately 3 inches long just under their collar bone (clavicle). The ICD will be placed under the tissue above the pectoral muscle. You may possibly see the outline of the device and may even feel it by pressing on your skin.

How long does the procedure take?

Implantation of an ICD takes 2-6 hours, depending on the lead system selected and the anatomy of the patient.

What is the procedure?

On the day of the procedure, you will be asked not to eat to drink anything after midnight.

If you have hair on your chest where the device will be placed, the staff will clip the hair to help prevent infection. You will also receive an antibiotic in your IV. The area where the physician will work will be painted with a solution that kills bacteria.

You will receive medication in your IV to help you relax. Most patients sleep through the procedure and have few memories of the surgery. During the procedure, your heart rhythm, blood pressure and the oxygen in your blood will all be continuously monitored.

You will be draped and your face will be covered for a short time. The doctor will numb the area where the ICD will be implanted. You may feel pressure in the area, but you should not feel pain. Please tell the staff if you are having any pain. It is their goal to be sure you are comfortable during the procedure.

After the incision, the physician will make a small opening under tissue below your skin. This is called a "pocket" and the ICD pulse generator will be placed in it. The physician will then use the subclavian vein, which runs near the collarbone (clavicle) to place the leads in to your heart. The leads are positioned in the appropriate chambers of the heart. The ICD will then be connected to the leads and tested to make sure it is properly functioning.

The incision will be closed and you will be allowed to wake up. Once awake, you will be returned to your room and may eat and drink.

In some instances, the testing of the device will be done by bringing you back to the lab some time after the procedure. If the test is done at a later date, the electrophysiologist will test the device by using a programmer to talk to your ICD. A small, specially designed wand will be placed over the ICD to allow a computer to communicate with the device. You will be asleep during the procedure and may not have a memory of it.

What should I do if I receive a shock?

If you receive one or two shocks, and are feeling fine, notify your electrophysiologist or the Pacemaker/ICD clinic the next business day. They will schedule a time for you to come in and will interrogate your ICD to review what was happening in your heart to cause the device to deliver therapy.

If you receive three or more shocks, you should call 9-1-1 and go to the nearest emergency room. DO NOT DRIVE YOURSELF TO THE HOSPITAL.

Special Instructions for Implantable Cardioverter Defibrillators (ICDs)

• MRI is contraindicated for patients with Implantable Cardioverter Defibrillators. You may have a CT scan.
• Please carry your ICD identification card with you at all times.
• Wear a medic alert bracelet or necklace. If you are unconscious, emergency health care professionals will know that you have an ICD that treats life threatening heart rhythms.
• If you use a cellular phone, use the phone on the opposite ear from the pulse generator. You should, also, not carry cell phones in a pocket directly over your ICD. This only applies to cellular phones and not to cordless phones you may have in your home.
• It is safe to walk through the theft detection devices at stores, but you should not stand in or near them for more than a few seconds.
• The electrophysiologists at Meriter Hospital do not routinely prescribe prophylactic antibiotic therapy for routine dental visits.
• If you have questions, please talk to your electrophysiologist.

Airport Safety

• You may walk through the metal detector at the airport without harm, but do not stand in the metal detector for more than a few seconds.
• Carry your ICD identification card with you so that airport security knows you have an ICD.
• Airport security may use the wand on you, but they should not hold it over the area of the pulse generator (ICD) for more than a few seconds.
• Avoid standing near the metal detectors at the airport.

Do Implantable Cardioverter Defibrillators (ICDs) wear out?

The ICD pulse generator runs on a battery and will eventually need replacing. The length of time the battery lasts is dependant on several factors:

• The type of device you received
• The amount of time the ICD is used to pace your heart
• The amount of energy that is needed to pace your heart
• How often you have received therapy for fast heart rhythms

The Pacemaker/ICD Clinic can estimate the amount of time left on the battery when they check the ICD in the clinic. The device has protective mechanisms built in to the programming to allow plenty of notification that the battery needs replacing. The Pacemaker/ ICD Clinic will let you know at your clinic visits that the battery is starting to get low, so that you can plan when to have it replaced.

To change the battery on an Implantable Cardioverter Defibrillator, the entire pulse generator has to be replaced. Most patients are discharged from the hospital the same day as the procedure.

You will be brought to the Electrophysiology Lab and prepared as if you were having a new implant. The cardiologist will numb the skin and make an incision at the site of the pulse generator. The old generator will be removed and the staff will assist the physician in checking the lead system to be sure it is still working well. Then a new pulse generator will be connected to the leads and placed back in the pocket. The cardiologist may decide to test the device, just as it was tested at the original implant. The suture line will be closed and you will be returned to your room.

Because changing the battery does not usually require the placement of new leads, the procedure is generally quicker. Typically the procedure takes 2 hours or less.

9/9/2008