Pacemaker & ICD

What is a pacemaker?

A pacemaker is a device that is implanted in the chest and supplies electrical signals that the heart needs to maintain a normal heartbeat.

There are three parts to a pacemaker:

The pulse generator produces the electrical signals. It is about the size of a matchbook, and contains a battery and electronic circuitry.
The leads are small wires that carry the signal from the generator to the electrodes. Where your doctor decides to place the leads depends on your particular heart problem.
The electrodes are located at the end of the leads and actually deliver the signal to the heart.

How does a pacemaker work?

The circuits of the pacemaker monitor your heart’s rhythm and deliver an electrical signal when it detects that the heart is beating too slow, so that your heart keeps beating at a normal rate. Many newer pacemakers have a feature that allows for temporary faster pacing during exercise -- when your heart must beat faster to meet the increased demand for blood and oxygen.

The pacemaker’s leads connect the generator to the part of the heart where the electrical impulse is delivered. There are two major types of pacemakers. Single chamber pacemakers have only one wire connecting the pacemaker to one chamber of the heart (either the right atrium or the right ventricle), and dual chamber pacemakers have wires connected to both the top and bottom chambers of the heart (the right atrium and the right ventricle). Your cardiologist will determine which type is needed. At the end of the wires are electrodes that actually deliver the electrical impulse to the heart.

Some newer devices are a combination of a biventricular pacemaker and an ICD in one unit for people with moderate to severe heart failure. In a normal heart, the right and left ventricles pump together, but if you have heart failure, they do not. The left ventricle then is not able to pump enough blood to the body. This can cause symptoms such as shortness of breath, cough, swelling in the ankles or legs, weight gain, increased urination, fatigue, or rapid or irregular heartbeat. The biventricular pacemaker part of the device treats the delay in heart ventricle contractions by keeping the right and left ventricles pumping together, while the ICD part helps prevent potentially fatal arrhythmias.

Who needs a pacemaker?

About 3 million people worldwide have pacemakers.⁴ In 2002, pacemakers were implanted in 199,000 people in the US (half were women).² Most pacemakers are implanted to treat bradycardia (a dangerously slow heart rate). If the heart does not beat fast enough, the brain and body don’t get the blood and oxygen necessary for them to function. Symptoms of bradycardia include:

Fainting
Dizziness
Lack of energy or fatigue
Shortness of breath

Some people do not experience any symptoms at all. Bradycardia often arises from problems with the heart’s natural pacemaker, known as the sinoatrial node or sinus node. These problems can be a result of older age, heart disease, or heart medications. Less often, pacemakers are implanted in people with heart block, a condition in which the heart’s normal electrical signal fails to reach the ventricles (the pumping chambers of the heart), causing a slow heart beat.

How well do women do after having a pacemaker implanted?

After getting a pacemaker implanted, women appear to live longer than men with pacemakers. In one study of about 6,500 people, women lived an average of 2 years longer than men despite being older than men when they had their pacemaker implanted.⁵ In another study of nearly 1,600 people over age 80, women were 30% less likely to die in the years following their pacemaker implantation than men.⁶

Can I just take medicine instead of getting a pacemaker?

In most cases, no, because the slow rhythm is related to underlying problems with the heart's pacemaker cells or conducting system. In these cases, medications are not effective. If you are suffering from many of the symptoms of bradycardia, the best course of treatment is to have a pacemaker implanted. Some people, however, may have pacemakers implanted and also take medication.

How do I prepare to have a pacemaker implanted?

Tell your healthcare provider all the medications you are currently taking. If you take a blood thinner, such as aspirin, warfarin (Coumadin), or clopidogrel (Plavix) you may be asked to stop taking it or to reduce your dosage before the procedure. You are not allowed to eat or drink after midnight the night before surgery.

What does implanting a pacemaker entail?

You will be awake during the procedure, but you will be given a sedative to help you relax and local anesthesia to numb the pain of the surgery. The sedative will be given through an intravenous (IV) line. You may feel the needle prick when the IV line is inserted into your arm. The surgical site near the left breast will be shaved if necessary and an antibacterial solution will be applied to the chest.

You will be hooked up to an electrocardiogram ( ECG) so that your heart rate and blood pressure can be monitored. For this, small sticky patches with wires attached will be taped to your body.

The surgeon will make a small incision into your skin. A tube called a catheter will be inserted into one of your veins, usually the large vein under your collarbone(the subclavian vein). Then the surgeon will insert the pacemaker wires into your heart through the vein. Once in place, the wires are tested to make sure that they work and are in the correct spot. This is known as "pacing" and it causes the heart to contract. You may feel like your heart is racing or beating faster. It’s important to tell your doctor or nurse any symptoms you feel, especially if you feel pain. Through the same incision, the surgeon creates a small pocket that the pacemaker generator will be inserted into. Next, the pacemaker is attached to the lead wires and inserted into the pocket, and the incision is closed. An X-ray will be taken after insertion to confirm correct placement of the pacemaker. Your doctor will use a magnetic wand called a “programmer” to make the final pacemaker settings. The procedure takes about 1 to 2 hours.

What happens after the procedure?

You will rest in bed until the sedative has worn off completely. When you are fully awake, you will be allowed to eat and drink. The incision site may be sore and you can take pain medication if needed.
Depending on your age and overall health, a short hospital stay may be recommended. Your physician will give you instructions regarding what level of activity is appropriate for you after the procedure.

You may be instructed not to bathe or shower for at least 5 days. During this time, it will probably be all right for you to sponge bath, but you should not get the bandages wet. After 5 days or so, you can wash normally with soap and water, but be careful not to apply any unusual pressure to the site of catheter insertion.

Complete recovery from the procedure can take about 3 to 6 weeks. During that time, the wires will firmly take hold where they were placed. You should avoid contact sports, heavy lifting or pulling, or raising the arm on the side of the pacemaker above your head until your physician says it is all right for you to do so. You should be able to resume sexual activity once your incision has healed, unless your physician instructs you otherwise. Ask your physician when you can return to work, because the nature of your job, your health status, and your progress will determine how soon you can return. You will probably not be allowed to drive for 1 week after pacemaker implantation.

Once healed, usually only a small bump is seen over the spot where the pacemaker was placed.

How often will the pacemaker need to be checked?

You will need to follow up with your cardiologist at regular intervals in order to monitor the device. This is done noninvasively, meaning it does not require surgery. After getting a pacemaker, you will probably see your physician twice within the first 6 months, and then again every 6 to 12 months, to see how the pacemaker is working and to check the life of the battery.¹ You may also have monthly monitoring over the telephone, known as transtelephonic monitoring. Signals from the pacemaker get converted into sound waves, which are sent over the phone, and received by a monitoring station at the other end of the phone, where they are reconverted back into the original signals so that your physician can interpret them. This cannot be done using cordless phones or cell phones, however, because of electronic interference.

The average pacemaker battery lasts about 5 to 8 years.⁴ You do not need to worry about your pacemaker battery running out unexpectedly. When the battery is running low, the elective replacement indicator (ERI) is activated, and your physician can detect this activation during a routine office visit. Once the ERI is activated the pacemaker will continue to work for 6 months, during which time you can schedule a replacement procedure.

Are there any special concerns for living with a pacemaker?

You will receive an identification card after your procedure that contains your name and other information, as well as the serial number and model of your pacemaker. You should keep this card with you at all times because you’ll need this information if there are problems with the device, or if you are in an accident or need to avoid certain magnetic devices.

The following are some common concerns of people with pacemakers:

Airport security checks. You can pass through airport security metal detectors normally, but a handheld wand detector should not be held near the pacemaker⁴

MRIs and X-rays. You should avoid MRIs, but X-rays are safe. In general, you should avoid strong electromagnetic fields (like those generated by an MRI)

Magnets. You should avoid holding strong magnetic items (like stereo speakers) near your pacemaker. Small magnets, like refrigerator magnets, are safe because they produce very weak electromagnetic fields. As a general rule, if you are unsure about whether an item is safe to hold near your pacemaker, maintain a distance of 6 inches between yourself and the item

Microwaves. Although people with very old pacemakers could not use microwave ovens, this is not true with today’s models. All household appliances are safe to use with a pacemaker⁴

Cell phones. You should hold cell phones at least 6 inches from the pacemaker, even when the phone is off. Don’t keep your phone in clothing pockets near the pacemaker, and use the ear opposite the pacemaker when using your cell phone⁴

Slot machines. You may be advised to avoid slot machines or to stay about 12 inches away from them

Roller coasters. Some newer roller coasters are also controlled by large magnets; you should not ride these types or any roller coasters with shoulder harnesses

Talk to your healthcare provider about any other precautions that may be necessary.

What are the risks of pacemaker implantation?

Serious complications are rare, but can include severe bruising and bleeding, infection, blood clots, or an electrode dislodging from the heart. Some people can develop pacemaker syndrome, in which the pacemaker is no longer synchronized with the heart’s own rhythm and attempts to pump blood through a closed valve. Symptoms of pacemaker syndrome are dizziness and fatigue. If you have a pacemaker and you experience any of these symptoms, contact your healthcare provider.

In very rare cases (about 2%), the wires of the pacemakers, called leads, need to be removed, usually due to infection, damage to the lead, or interference with blood flow in the heart. Women have a higher risk of complications during this surgery (called pacemaker lead extraction), though this may be because women are often older than men when they receive a pacemaker.^{7, 8} New leads are sometimes placed during this procedure. In some cases, such as when you have an infection, the leads will be implanted at a later date because the infection must be cleared up before new leads can be implanted.

What is an implantable cardioverter defibrillator (ICD)?

An ICD is a device implanted in the chest to monitor and, if necessary, correct episodes of serious abnormal heart rhythms. There are three parts to an ICD:

The pulse generator, which is responsible for generating the electric shock, is a small box (from 1 to 2 inches wide and weighing ½ to 3 ounces) that also contains a battery.

The leads are small wires that carry the shock from the generator to the electrodes. Where your doctor decides to place the leads depends on your particular heart problem.

The electrodes actually deliver the shock to the heart.

ICDs are most often implanted in the upper chest. Sometimes they are placed beneath the abdominal skin or muscles at the “bikini line” for cosmetic reasons because a small lump can be seen where the ICD has been implanted.⁹

How does an ICD work?

An ICD works by delivering a small low-energy pulse to the heart that you can’t feel, much like that from a pacemaker, in order to “reset” the heart. This process is called cardioversion. In cases where the heartbeat is so rapid that you may die from it, the ICD will also deliver an electric shock, or defibrillation, which can be painful or very uncomfortable. Some people describe the feeling as being kicked in the chest.⁹ Occasionally, the ICD will deliver a series of shocks if the rhythm problem recurs or if one shock is not enough to correct a serious, prolonged, fast heart rhythm.
Some newer devices are a combination of an ICD and biventricular pacemaker in one unit for people with moderate to severe heart failure. In a normal heart, the right and left ventricles pump together, but if you have heart failure, they do not. The left ventricle then is not able to pump enough blood to the body. This can cause symptoms such as shortness of breath, cough, swelling in the ankles or legs, weight gain, increased urination, fatigue, or rapid or irregular heartbeat. The biventricular pacemaker part of the device treats the delay in heart ventricle contractions by keeping the right and left ventricles pumping together, while the ICD part helps prevent potentially fatal arrhythmias.

Who needs an ICD?

In 2002, ICDs were implanted in 63,000 people in the US, of whom 17% were women.² ICDs are implanted in people who have survived one or more episodes of ventricular tachycardia, when the heart beats fast due to electrical signals from the ventricles, or ventricular fibrillation, when electrical signals in the ventricles are fired in a very fast, uncontrolled manner, causing the heart to quiver rather than beat and pump blood. ICDs are also implanted as a preventative measure in people at high risk for developing ventricular tachycardia, ventricular fibrillation, or sudden cardiac death.⁹ You may be at high risk for these problems if you’ve had a heart attack and the left ventricle of your heart is damaged. People who have both heart disease and a heart rhythm disturbance are good candidates for an ICD. ICDs are usually not implanted in people who have an abnormal rhythm during the first 48 hours after a heart attack; external defibrillators or medication will usually be enough to resolve these early arrhythmias, which are often temporary.¹⁰ An arrhythmia that occurs more than 48 hours after a heart attack indicates a possible recurrent rhythm disturbance that may require an ICD to be implanted.

How well do women do after having an ICD implanted?

In women, ICDs for tachycardia (fast heart beat) are less successful at correcting the fast heartbeat and have a higher rate of complications.¹¹ Although an ICD should slow the heart beat, women were 3 times more likely to have their heart rate further increased by ICDs compared with men. In terms of preventing sudden cardiac death, ICDs work equally well in both men and women.¹²

Can I just take medicine instead of getting an ICD?

Medication is often used to prevent life-threatening ventricular tachycardia and ventricular fibrillation; people at low risk for developing these ventricular arrhythmias are usually treated with medication alone. One study of people who had already had a life-threatening arrhythmia (and were therefore high-risk) found that people who had an ICD implanted were 39% less likely to die after 1 year compared with people treated with medication alone.¹³ Other research has also indicated that the advantage of ICD use over medication therapy benefits people at highest risk more than people at moderate risk.¹⁴ An ICD and medications are frequently used together.

How do I prepare to have an ICD implanted?

What does the ICD procedure entail?

You will be hooked up to an electrocardiogram (ECG) so that your heart rate and blood pressure can be monitored. For this, small sticky patches with wires attached will be taped to your body.

The surgeon will make a small incision into your skin. A tube called a catheter will be inserted into one of your veins, usually the large vein under your collarbone, the subclavian vein. Then the surgeon will insert the ICD wires into your heart through the vein. If the ICD will be placed in the abdomen, a different procedure is used. Once in place, the wires are tested to make sure they work and are in the correct spot. Through the same incision, the surgeon creates a small pocket that the ICD generator will be inserted into. Next, the ICD is attached to the lead wires and inserted into the pocket and the incision is closed. After implantation, the physician will test the ICD several times by causing the heart to fibrillate or “quiver” to make sure the ICD responds properly. Immediately after the procedure, an X-ray will be taken to confirm the proper placement of the device. The procedure takes about 1 to 2 hours.

What happens after the procedure?

Depending on your age and overall health, a short hospital stay may be recommended. You will be given instructions regarding what level of activity is appropriate for you after the procedure. Your physician may also adjust the ICD by using a magnetic wand that is passed over the chest, a process that you should not feel. Your physician may also induce tachycardia or fibrillation (as they did during the implantation procedure) to program the ICD for maximum efficiency. This will also allow you to learn what an ICD shock feels like.

Complete recovery from the procedure can take about 3 to 6 weeks. During that time, the wires will firmly take hold where they were placed. You should avoid contact sports, heavy lifting or pulling, or raising the arm on the side of the ICD above your head until your physician says it is all right for you to do so. You should be able to resume sexual activity once your incision has healed, unless your physician instructs you otherwise. Ask your physician when you can return to work, because the nature of your job, your health status, and your progress will determine how soon you can return.

You will probably also have a short restriction on driving. Episodes of ventricular tachycardia can cause you to temporarily lose consciousness because there may be a 5 to 15 second interval before the ICD delivers its shock.⁹ According to the National Highway Traffic Safety Administration, depending on the severity of your condition, you will need to be episode-free for 3 to 6 months before you can resume driving.¹⁵ This time may be shortened if you are also taking antiarrhythmic medication. When you do resume driving, you should not drive long distances or use your car’s cruise-control setting.

Once healed, usually only a small bump is seen over the spot where the ICD was placed.

How often will the ICD need to be checked?

You will need to follow up with your cardiologist at regular intervals in order to monitor the device. This is done noninvasively, meaning it does not require surgery. If you have an ICD, your physician will see you every 1 to 3 months to see if any rhythm disturbances have been detected, what electrical treatments (such as any defibrillation shocks) have been delivered, and if these treatments need to be modified in some way.⁹ You may also have monthly monitoring over the telephone, known as transtelephonic monitoring. Signals from the ICD get converted into sound waves, which are sent over the phone, and received by a monitoring station at the other end of the phone, where they are reconverted back into the original signals so that your physician can interpret them. This cannot be done using cordless phones or cell phones, however, because of electronic interference.

The battery life will also be checked; ICD batteries can last from 3 to 6 years,⁹depending on how many electrical shocks have been given. You do not need to worry about your ICD battery running out unexpectedly. When the battery is running low, the elective replacement indicator (ERI) is activated, and your physician can detect this activation during a routine office visit. Once the ERI is activated, your ICD will continue to function for 6 months, during which time you can schedule a replacement procedure.

Are there any special concerns for living with an ICD?

You will receive an identification card after your procedure that contains your name, emergency information, and the serial number and model of your ICD. You should keep this card with you at all times because you’ll need this information if there are problems with the device, or if you are in an accident or need to avoid certain magnetic devices.

The following are some common concerns of people with ICDs:

Airport security checks. You can pass through airport security metal detectors normally, but a handheld wand detector should not be held near the ICD⁹

MRIs and X-rays. You should avoid MRIs, but X-rays are safe to have. In general, you should avoid strong electromagnetic fields (like those generated by an MRI)

Magnets. You should avoid holding strong magnetic items (like stereo speakers) near your pacemaker. Small magnets, like refrigerator magnets, are safe because they produce very weak electromagnetic fields. As a general rule, if you are unsure about whether an item is safe to hold near your pacemaker, maintain a distance of 6 inches between yourself and the item

Microwaves. All household appliances are safe to use with an ICD⁹

Cell phones. You should hold cell phones at least 6 inches from the ICD, even when the phone is off. Don’t keep your phone in clothing pockets near the ICD, and use the ear opposite the ICD when using your cell phone⁹

Slot machines. You may be advised to avoid slot machines or to stay about 12 inches away from them

Roller coasters. Some newer roller coasters are also controlled by large magnets; you should not ride these types or any roller coasters with shoulder harnesses

Talk to your healthcare provider about any other precautions that may be necessary.

What are the risks of ICD implantation?

Serious complications are rare, occurring in 1% to 2% of people undergoing ICD implantation. These complications include severe bruising or bleeding, formation of a blood clot, infection, or dying. Anxiety and depression are common in people who have an ICD implanted. Elevated levels of both conditions have been reported in about 20% to 60% of people after ICD implantation.^16-19 Almost 40% of people with ICDs have the symptoms of an anxiety disorder.²⁰ Because an ICD shock is painful, it’s not uncommon to fear an ICD shock. If you have several shocks, you may experience increased anxiety and depression.^{21, 22} Cognitive behavior therapy, which is a form of therapy using imagery, self-instruction, and related techniques, has been shown help reduce depression and anxiety.²³

References

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17. Kamphuis HC, de Leeuw JR, Derksen R, Hauer RN, Winnubst JA. Implantable cardioverter defibrillator recipients: quality of life in recipients with and without ICD shock delivery: a prospective study. Europace. 2003;5:381-389.
18. Morris PL, Badger J, Chmielewski C, Berger E, Goldberg RJ. Psychiatric morbidity following implantation of the automatic implantable cardioverter defibrillator. Psychosomatics. 1991;32:58-64.
19. Schohl W, Trappe HJ, Lichtlen PR. [Acceptance and quality of life after implantation of an automatic cardioverter/defibrillator]. Z Kardiol. 1994;83:927-932.
20. Sola CL, Bostwick JM. Implantable cardioverter-defibrillators, induced anxiety, and quality of life. Mayo Clin Proc. 2005;80:232-237.
21. Heller SS, Ormont MA, Lidagoster L, Sciacca RR, Steinberg S. Psychosocial outcome after ICD implantation: a current perspective. Pacing Clin Electrophysiol. 1998;21:1207-1215.
22. Luderitz B, Jung W, Deister A, Marneros A, Manz M. Patient acceptance of the implantable cardioverter defibrillator in ventricular tachyarrhythmias. Pacing Clin Electrophysiol. 1993;16:1815-1821.
23. Frizelle DJ, Lewin RJ, Kaye G, et al. Cognitive-behavioural rehabilitation programme for patients with an implanted cardioverter defibrillator: a pilot study. Br J Health Psychol. 2004;9:381-392.