What is an Implantable Cardioverter-Defibrillator?
When your heart rate is too fast for your heart to pump effectively, an implant-able cardioverter-defibrillator (ICD) may be recommended. An ICD is an implantable electronic device that continuously monitors or senses your heart rate. When your ICD senses an abnormal rhythm, it will deliver an electrical shock to your heart to try to stop the fast rhythm. Your physician can also program the ICD to "pace" your heart back to a normal rhythm when it is going too fast. All ICD's have back-up pacing for rhythms that arc too slow.
The implantable defibrillator includes a defibrillator includes a "pulse generator" and "lead(s)." The pulse generator, or battery pack, is approximately half the size of a deck of cards and is implanted beneath the skin of your left chest or abdomen. The pulse generator is connected to the lead system, which is connected to your heart. The leads are insulated flexible wires that can be placed in your heart.
The lead carries a signal from the heart muscle to the pulse generator when your heart beats. When an abnormal heart rhythm is sensed by the pulse generator, the lead will deliver a shock or pacing from the pulse generator back to your heart.
How is the ICD Implanted?
The ICD is implanted in the cardiac catheterization laboratory by two electro-physiologists. Your physician will discuss the implantation with you prior to the procedure. Once the physician has spoken with you and your questions have been answered, you will be required to sign an informed consent form. You will not be able to eat or drink for eight hours prior to your surgery.
You will be placed under the care of an anesthesiologist who will give you medication to help you relax during the procedure. A local anesthetic will be given at the site of the ICD implant, usually beneath the skin on the left side of the upper chest. After the area is numb, the physician will create a "pocket" or space for the generator. The lead system will be placed in your heart (illustration above), through a vein in your upper chest and guided into position with the assistance of fluoroscopy (X-ray).
Once the lead is secured in place, it is attached to the generator. While you are asleep, the device is programmed and tested to be certain that it treats your fast arrhythmia. The three inch incision will then be sutured and a dressing will be placed over it. The entire procedure will last from two to four hours.
What Happens After the Surgery?
After surgery you will he admitted to a monitored unit for overnight observation. You will be instructed not to move the arm on the side of the implant. This gives the lead time to stabilize in your vein and heart. If you feel soreness after this procedure, notify the nurse who will give you medication to make you more comfortable.
One month after implant, you will need to have your ICD tested to evaluate its functioning. This gives your physician an opportunity to expand the programming of the device specifically for your arrhythmia. This is done in the EPS laboratory on an outpatient basis and will take about one hour.
How Should I Care for Myself Once I Go Home?
You must do several things to care for yourself after you leave the hospital. Antibiotics are sometimes prescribed and may need to be taken for a full 5 day course. Check your temperature twice daily to determine if it is elevated (possibly indicating an infection).
The incision requires a dressing change once a day for seven days. Inspect the incision daily for redness, swelling or drainage. If you develop swelling, drainage, increased wound tenderness, increased redness or an elevated temperature, please notify us immediately at (650) 723-7111.
After the third day following implant, you may take off the "daily dressing" and shower. You can allow soap and water to run over the area but avoid scrubbing. Keep the force of the water from spraying directly on the incision and gently and thoroughly dry the incision with a towel. Do not lift or move the arm on the side of the ICD above your head for two weeks after the ICD implantation.
You should have a follow-up appointment with your physician within 7 to 10 days of surgery. At this visit, the nurse and physician will check your incision and also assist you with guidelines for increasing your activity.
Will My Day-to-Day Life Change?
After you go home, you may have some discomfort at the incision site. Your physician will give you some medication to make you more comfortable. You should slowly increase your activity over several days. Avoid heavy lifting, and activities that involve rough contact with the area where the pulse generator and leads are located.
When an abnormal heart rhythm occurs, it may trigger your ICD to "shock" your heart to correct the rhythm. If you feel the symptoms of your fast heart rhythm, you should find a place to sit or lie down. You may feel dizzy, lightheaded or briefly lose consciousness prior to a shock. If you are touching someone when the device delivers a shock, they may feel a sensation but it will not harm them. Experiences with defibrillator shocks vary among patients from a light thump to a strong kick in the chest. Whether you feel the ICD treating your arrhythmia or not, it is important to remember that the ICD is always monitoring your rhythm and will treat your arrhythmia when necessary. It is normal to feel startled following a shock and often helpful to talk about the event.
You need to have your defibrillator checked every four months. This visit is required to check the ICD battery and ensure that the device is functioning properly. It is important that you keep these appointments.
You will receive an ICD identification (ID) card while you are in the hospital, or in the mail after you go home. You should carry this ID at all times. Most electrical and mechanical devices will not interfere with your ICD- In general, you may use any appliance or go anywhere except into areas where strong electrical interference may exist. Always tell any doctor or dentist who treats you that you have an ICD.