Implantable Device Replacement Procedure

Pacemakers and implantable cardioverter defibrillators (ICDs) are heart devices. They are surgically implanted in people who need them. Pacemakers are used to treat slow heart rhythms. ICDs stop dangerous, fast heart rhythms.

These devices have two main parts: a pulse generator and a set of wires (leads).

The pulse generator is a small metal box. It contains electric circuits and a battery. During the first placement of your heart device, your doctor put this generator under your skin or the muscles of your chest wall. Normally, these generators are powered by lithium batteries. They generally last up to 10 years before they need to be replaced. Time for replacement varies depending on the type of device you have, how much energy it uses, and the amount of time it paces your heart. To replace the pulse generator, you will need an implantable device replacement procedure.

The leads are wires that run between the pulse generator and your heart. These leads can deliver a burst of energy from the pulse generator. This energy can cause your heart to beat more quickly (in a pacemaker) or it can stop fast heart rhythms (in an ICD). To do this, the leads must make contact with your heart. Most leads travel through a vein to attach to the right side of your heart. They are often attached to the heart wall with a small screw or hook.

Replacing the pulse generator is a simple outpatient surgery similar to your initial implant but this time only the generator will be replaced. If the original leads are working normally, they will continue to be used with the new generator.

Your old generator will be disconnected from your leads. Then it will be taken out. Then your surgeon will put a new generator in the same pocket and connect it to the leads that are in place. At that point, your new ICD or pacemaker can work just as before.

In rare cases, you may need to have the leads removed along with or instead of the generator if, for example, there is a malfunction with one or more of the leads. This is a more complex procedure.

If you are completely dependent on the pacemaker to maintain a heartbeat, your doctor may use a temporary pacing wire during the procedure to help your heart to beat while the generator is being changed out and replaced. This temporary wire would then be removed once the new generator is connected and working.

Most generators need to be replaced within 5 to 15 years after they are inserted. This depends on how much you are using the implanted device, which affects battery life. Your doctor can check the battery and functioning of your device. Most of the time, these devices give plenty of warning that they are nearing the end of their battery life. You often have a few months to schedule your replacement procedure even after the device sets off the replacement interval.

Sometimes, you need to replace your generator before the battery life ends. This may happen if:

• Your generator starts to malfunction or stops working.
• You have an infection at the site of the generator, and you need more than antibiotics to clear it up. In this case, the whole pacemaker/ICD system would need to be removed including wires.

It's important for your pacemaker or ICD to work well. The pacemaker can keep your heart from beating too slowly. ICDs can stop the kind of dangerous heart rhythms that can lead to sudden death. You may need an ICD if you had a sudden cardiac arrest, heart failure, or heart rhythm problems.

This procedure is very safe, but it comes with some rare risks. These include:

• Infection
• Bleeding
• Allergic reaction to anesthesia
• Damage to the leads

There is also a small risk that you will need your leads replaced at the same time of the device replacement. This needs a more complex surgery. In most cases, your surgeon will know ahead of time if you will need this.

Your risks may differ depending on your age, health issues, where your generator was originally placed, and if your leads need to be replaced. Ask your doctor about your outlook before your surgery.

Your doctor may tell you not to eat or drink anything before midnight of the day of your procedure. Follow your doctor's orders about what medicines to take. Don't stop taking any medicine unless your doctor tells you to do so. It's a good idea to ask someone to drive you home after the procedure.

Your doctor may do some tests before your procedure. These may include an electrocardiogram. This test is done to check your heart rhythm. Or you may need an echocardiogram. This test evaluates heart function. Routine blood tests are also done before the procedure.

Just before the procedure, someone may shave your skin above the area where you will have the incision. Someone will also start an I.V. (intravenous) line. This is done so you can get medicine during the surgery.

The procedure often takes less than an hour. In general you can expect the following:

1. You may be given medicine through an I.V. line. This will make you feel sleepy and relaxed.
2. Antibiotics will be given as well.
3. Medical staff will closely watch your heart rate, blood pressure, and other vital signs.
4. After cleaning the area, the doctor injects medicine to numb the skin over your generator. This will keep you from feeling pain as the device is replaced.
5. The surgeon makes a cut into the pocket of skin and tissue surrounding the generator and gets access to the generator.
6. The surgeon disconnects your old generator from its leads. Then the surgeon takes it out of your body.
7. The pocket is then cleaned with antibiotic solution.
8. The surgeon puts your new generator in the same pocket where the old generator was. It's attached to your old leads.
9. Medical staff will check that the new device is working correctly.
10. Sometimes an antibiotic pouch will be placed with the new generator to prevent infection.
11. The surgeon will close up the pocket and the small incision in your skin.

Your doctor will keep track of you after the procedure. You may not remember much of the procedure. In most cases, you can go home after a couple of hours.

Try to take it easy the rest of the day. Make sure someone is around to help you. You can eat your normal diet as soon as you are able to. You may have some minor pain after the procedure. Ask your doctor if you can take over-the-counter (OTC) medicines.

Your doctor will tell you how the procedure went. Be sure to follow all of your doctor's instructions. You will need to care for your wound. You may also need to take antibiotics for a few days after the procedure. You should keep the wound dry until your doctor says it's okay to shower or get it wet. This will help reduce the risk of infection.

Tell your doctor right away if you have heavy bleeding from your incision or drainage from the incision, a fever, or other severe symptoms. You will likely have a checkup a week or so after your surgery. Your doctor will keep track of your ICD or pacemaker regularly, as before.

Before you agree to the test or procedure make sure you know:

• The name of the test or procedure
• The reason you are having the test or procedure
• What results to expect and what they mean
• The risks and benefits of the test or procedure
• What the possible side effects or complications are
• When and where you are to have the test or procedure
• Who will do the test or procedure and what that person's qualifications are
• What would happen if you did not have the test or procedure
• Any alternative tests or procedures to think about
• When and how you will get the results
• Who to call after the test or procedure if you have questions or problems
• How much you will have to pay for the test or procedure