Implantable Heart Rhythm Devices
Devices can be implanted under the skin during a relatively minor operation to:
1) diagnose whether or not a disturbance of heart rhythm is the cause of symptoms;
2) prevent slowing of the heart rhythm to dangerously low levels, and/or
3) treat dangerously fast rhythms.
Diagnosis of heart rhythm disturbances:
To do this we implant a device the size of a BIC lighter under the skin below the collar bone. The operation is done on an outpatient basis under local anesthesia and takes about 15-20 minutes to perform. This device is called "Reveal" and is manufactured by Medtronic. The incision is about 2 centimeters (a bit less than 1 inch). Here is what it looks like:
There are no wires to connect it to the heart. It essentially a simple ECG machine with a non-so simple recording capability. Once implanted, this device allows us to determine whether or not a disturbance of heart rhythm is the source of loss of consciousness. How does it work? It constantly monitors the heart rhythm. Once activated, it stores a segment (or loop) of the ECG in to memory. How is it activated? You can activate it with a wand around the time of symptoms or it will auto-activate upon recognition of excessive slow or fast heart rates.
It is also activated automatically when a slow heart rate or very fast heart rate is detected. The newest generation devices have a battery life of about 3-4 years. When the battery is dead, it can be taken out (explanted) or may be left in, as it poses no harm just sitting there. If an abnormal heart rate is detected as the cause of symptoms, then the device can be taken out at the time a therapeutic device is implanted - a pacemaker or pacemaker-defibrillator combo).
Pacemaker: treatment of slow heart beats
The pacemaker is a small device that is implanted in under the skin below the collar bone. Again the operation is done under local anesthesia with a mild general sedative administered by the anesthesiologist or a specially trained nurse. The incision is about 4 centimeters long. The pacemaker is directly connected to the heart by special wires that are inserted into the veins that connect to the heart. These wires are advanced to the appropriate positions in the right side of the heart using x-ray guidance. A pacemaker constantly monitors the heart rhythm. Once your heart rate is below a pre-set number, the pacemaker sends a small electrical charge to the heart muscle tissue to initiate a contraction. These devices may have one, two or three wires. The first two types (one wire or single chamber and two wire or dual chamber) are used exclusively in patients whose heart rates are too slow (whether the slowing is a constant or intermittent phenomenon, at rest or with exertion). The three-wire type is typically used for patients with congestive heart failure. Implantation of the single wire device typically takes about 30 minutes, the two wire about 45- 60 minutes and the three wire about 2 hours.
Pacemaker/Defibrillator - the ICD:
These devices, also known as ICDs (internal cardioverter-defibrillator) are implanted in patients who have had dangerously fast heart rhythms or who are at very high risk for dying suddenly of a dangerously rapid heart rhythm. While they also have the same function as a pacemaker, the main purpose is to recognize a very fast, life threatening heart rhythm and treat it with a treatment called overdrive pacing or with delivery of a large electric charge (you've seen the "paddles" on medical shows - this is a fully automatic internal form of the paddles). The device is a fair amount larger than a pacemaker but the implant technique is the same. Again, the duration of implant depends on the number of wires being put in. What is different compared to a pacemaker is the extra few minutes it takes to test whether or note the ICD can appropriately detect dangerously fast rhythms and deliver a life saving shock.
LOCATION: The operations may be done on an out or inpatient basis, depending on whether or not the symptoms were severe enough to require hospital admission. Patients receiving the REVEAL may go home shortly after the operation. Those receiving a pacemaker may or may not go home the same day. And those who receive an ICD are observed over night.
POST-IMPLANT INSTRUCTIONS: For the first three weeks after implant, we ask that patients not drive. In addition we do not want our patients with fresh implants to lift, reach, carry or push off with the arm on the side of the pacemaker. One week after discharge from the hospital, we see the patients in the office for a wound check and brief pacemaker evaluation. Thereafter appointments occur at 1 month after implant and every 6 months thereafter. Some companies make devices that allow the implanted device to be checked form home.
What are the risks and precautions?
Generally, use of ICDs is considered safe and highly effective. However, there are potential risks associated with any implantable device system. Risks include, but are not limited to, infection at the surgical site and/or sensitivity to the device material, failure to deliver therapy when it is needed, or receiving extra therapy when it is not needed. After receiving an ICD, you will have limitations with magnetic and electromagnetic radiation and electric or gas powered appliances and tools with which you are allowed to be in contact. Although many patients benefit from the use of these products, results may vary. Please note that there are other important risks and precautions that you will need to review with your physician. Your physician should review all risks and benefits with you.
What happens during the implant procedure?
The following is intended as a general overview. The implant procedure is typically quick, low risk, and usually done under local anesthesia. It does not require open-heart surgery, and most people typically stay overnight. Patients are normally sedated throughout the procedure and should not feel any pain. Your doctor will make a small incision in the upper chest and guide the leads through a vein and into your heart. Your doctor will connect the leads to the ICD and program the device. Then the ICD will be inserted beneath the skin and the incision in your chest will be closed. Your physician will test the ICD to ensure that it is working properly. Your experience may differ, so please talk to your doctor for specifics regarding your implant.
What happens following the procedure?
Following surgery, you will typically stay in the hospital overnight and go home the next day. You will see a bump under your skin where your device is located and the area may be tender. Generally, you should limit arm movement on the side of your ICD for about 2 to 6 weeks. Your doctor or nurse will provide you with more specific care instructions, but you can expect to gradually return to your everyday activities shortly after the procedure. If you have any questions, please ask your doctor or nurse.
What about follow-up after the procedure?
After the implant, the doctor who implanted your defibrillator will work with the doctor who manages your heart disease. You will still need to take your medication as prescribed and have your ICD checked from time to time. Ask your doctor or nurse about your schedule for follow-up visits with each of your physicians. It is important to keep appointments with each of your doctors and to follow the recommended daily care instructions to ensure the best possible results. Depending on what type of device you have, you might be able to use a monitoring service that allows you to transfer information from your device to your clinic over a telephone line. This service may reduce the number of clinic visits you need. Your device helps you only when it is functioning properly. It is important to receive regular follow-up care by your electrophysiologist and the doctor or nurse treating your heart failure.
What happens after a shock? Making a plan.
If your ICD detects a problem with your heart rhythm, it may deliver a shock to your heart. People describe the shock as surprising and uncomfortable, and sometimes painful, but it passes quickly. It also means the ICD has done its job and that it may have saved your life. Your doctor or nurse will give you specific directions on what to do immediately after receiving a shock. Work with them to develop a plan that is right for you.
If you do receive a shock:
- 1. Follow the directions your doctor or nurse gave you about what to do after receiving a shock.
2. Stay calm and find a quiet place to sit or lie down.
3. Take notice of how you feel and tell others.
4. Ask a family member or friend to stay with you until you feel better. Anyone touching you while the device is delivering a shock might feel the muscles in your chest and upper arms contract. The shock will not harm the person touching you.
5. Instruct the friend or family member to call for an ambulance if you receive a shock and remain unconscious for more than 1 minute.
6. If you do not feel well after the shock, ask someone to call your doctor and help get you to the nearest emergency room.
Put this plan in a handy place so you can get to it easily. Also, make sure to share it with your family and other care givers, so they can understand how to help you. It is helpful to understand that what you were doing at the time of the shock did not cause the shock. Generally, you will still be able to do the activities you enjoy. Although getting a shock may reduce your confidence for a short time, it is important to return to your everyday activities and focus on enjoying life.
Will I be able to drive?
Most people with an ICD are able to resume driving depending on their doctor's recommendation, and the laws and insurance rules in their state.
Will I be able to travel?
Most people with an ICD can travel without taking special precautions, but you should discuss this with your doctor. Most patients can travel without problems soon after their ICD implantation.
Will I have a problem with airport security?
Airport security systems may detect the metal of your ICD and you may be asked to undergo an additional search. Patients receiving ICDs are given a device identification card, which can be presented at airport security if needed. You can also request a hand search. You should request that any handheld screening devices be kept away from your ICD, since they have the potential to trigger defibrillation therapy.
Can I walk through anti-theft systems?
Yes. Sometimes, however, the systems located in stores, libraries, and other buildings may temporarily interfere with your ICD if you stop or linger near the equipment. Simply walk through the system at a normal pace.
Are physical activities safe?
Most physical activities are safe. An ICD can tell when your heart rate increases due to normal physical activities and when it increases because of a problem with your heart. Discuss your activity level with your doctor to determine what is best for you.
What about intimacy?
Most patients can resume intimate activity. People who have an ICD may wonder if the device could deliver a shock during sexual activities. This is rare, but possible. The shock will not hurt your partner. Your doctor or nurse can also provide helpful information on the subject of intimacy.
How will I know if my ICD is working properly? What happens if the battery runs out?
The doctor who implanted your device will schedule regular follow-up appointments to check your device. If your doctor finds the battery low, he or she will discuss a replacement procedure. Because the battery inside the device cannot be recharged, the entire device must be replaced, usually after
5 to 7 years.
What will I do if I have concerns?
Make a list of any worries you might have about your condition or the ICD. Discuss each concern with your doctor or nurse, your loved ones, or other appropriate sources of information who can help you to develop a plan about how to cope with your concerns.
How do I adjust to having an ICD?
Each person adjusts a little differently. Although many patients benefit from the use of these devices, individual results may vary. Your doctor will discuss the benefits and risks with you. The goal is for you to lead a more normal life as soon as possible. Build your confidence by making plans with friends and family. You may want to consider participating in a support group. If you have problems adjusting, there are many other resources to help.