In  addition  to  drugs  and  nonsurgical  procedures,  several types  of surgery can restore  your heart’s rhythm.  Implantation of a pacemaker can treat bradycardia (slow heartbeat);  an internal  cardioverter- de?brillator can correct more serious arrhythmias; or a procedure called maze surgery can be performed  on some people with atrial ?brillation.


A pacemaker  is a battery-powered unit  that  regulates  your  heart’s rhythm.  Most  pacemakers  are  implanted  in people  whose sinoatrial node  is firing  too  slowly as a result  of age, heart  disease, or  heart medications; the pacemaker takes over for the sinoatrial node if it fails to start.  In a person  with heart  block, the  device replaces a blocked pathway. Today pacemakers  not  only “pace” your heart’s rhythm  but also have a “demand” sensor that can speed up or slow down your heart rate in response to your activity level, just as your heart would naturally.

The  device itself, which is about the size of a man’s watch, contains a battery and an electronic pulse generator, with either one or two leads that  are threaded  into your heart.  The  device is programmed to read whether  your heart  rate is within an acceptable  range for you. If it is not, the pacemaker generates an electrical impulse to stimulate a heart beat at an appropriate rate. A single-chamber pacemaker has one lead that is positioned in one heart chamber, the right atrium or ventricle; a dual-chamber unit has two leads that are threaded  into both the right atrium and the right ventricle. The  pacemaker can remain in place for several years before the batteries require replacement.

For people with heart failure or with certain physical characteristics, a third lead may be placed in the back of the heart through a side vein. This is called biventricular pacing. While more complicated to perform than the usual insertion of a pacemaker, this procedure can make some people with heart failure feel much better by coordinating the heart’s contractions.

How a Pacemaker Is Implanted

To have a pacemaker implanted,  you will need only a mild sedative and a local anesthetic  in the  area  of your  upper  chest.  First  the  doctor makes  a small incision  in the  skin under  the  collarbone.  The  thin, coated leads are threaded through a blood vessel under your collarbone and positioned  in your heart under X-ray. Then they connect the leads to the pacemaker unit and slip it under your skin, also just under your collarbone.  You will notice  only a small bump at the site. The  proce- dure will be over in 1 to 2 hours, and complications are rare. Serious or life-threatening complications  occur  in less than  1 percent  of cases. Infection of the pacemaker is rare but generally requires that the pace- maker  be removed.  Sometimes  less serious  complications  can occur such as bleeding, collapse of a lung, or the pacemaker’s leads may need repositioning.

You will probably be able to return to your routine activities in a few days. Your doctor may tell you to avoid heavy lifting or vigorous move- ment of your arm on the side of the pacemaker.

Living with Your Pacemaker

You will need to have regular checkups. The  checkups are more frequent  until the pacemaker site heals com- pletely; then they occur about every 3 to 6 months, for monitoring. Your doctor will evaluate your pacemaker by moving an electronic  programmer over the device. The  programmer relays information about pacemaker function  and  the  life of the  battery,  and  it can also change  the programming (pacing instructions)  of the device if necessary. In addition  to the of?ce checkups,

your doctor may also give you instructions  for how to have some monthly evaluations done by telephone.

When  the battery begins to wear down, your pace- maker will slow down somewhat, but it won’t stop sud- denly.  Your  doctor  will be  able  to  detect  the  first warnings that the battery  is running  down before you have  any  sensation  of it.  When  the  battery  needs replacing,  you will need  surgery  to  implant  a new device. This  procedure  requires  local anesthetic,  but because the leads usually do not need replacement, the procedure  is somewhat simpler than the original implantation.

Your  doctor  will also give you  an  identification card  that  provides  specific  information about  the device you have. It is important to show this card to health-care professionals  and to airport  security  staff

Once  your pacemaker  is in place and the  implant site has healed, you most likely can participate  in all of your usual activities. You and your doctor  can review any possible restrictions—such as full-contact sports— that  might  apply to you. Always feel free to ask your doctor about any questions you have about appliances, medical procedures, or other  considerations that  you

think might affect your pacemaker. In general, it’s a good idea to be aware of your surroundings and alert for any circumstances  that might interfere  with the electronic  circuitry in your pacemaker.

Although your pacemaker is not likely to restrict your life in signif- icant ways, it is important to remember that  there  are many things your pacemaker cannot do. It cannot protect  you, for instance, from a heart  attack  caused  by blocked  arteries.  It  also cannot  necessarily replace your need for medications, including  heart-related drugs for conditions  such as high blood pressure, angina, or even other forms of arrhythmia.

Implantable Cardioverter-Defibrillators

The internal cardioverter-de?brillator (ICD) is a battery-operated unit, only slightly larger than a pacemaker, that is implanted under your skin to monitor  and correct your heart’s rhythm. All current ICDs also func- tion as pacemakers. An ICD  is usually placed in a person with a dam- aged heart  (as from a heart  attack) who has had or is at high risk of having life-threatening heart  rhythms,  such as ventricular  tachycardia or ventricular  ?brillation.  It may also be used for some people  with severe atrial ?brillation.

An ICD  can deliver  the  same sort  of low-energy,  imperceptible pulses that a pacemaker does. Furthermore, the ICD monitors the heart using the same technology.  De?brillators are different from pacemak- ers in that they also monitor  for very fast heart rates as well as for bradycardia. The  ICD  can also deliver higher-energy pulses (shocks) to the heart  when  it detects  more  serious  or  sustained  rapid  arrhythmias. These  stronger  impulses are called de?brillation shocks, and they are often life-saving.

A person  with an ICD  can feel these stronger  impulses—usually a single  shock,  but  sometimes  a series of them—and  they  are  often described as feeling like a quick thump or kick in the chest. Depending on the level of consciousness you have at the time of the shock, it may be painful (if you are not sedated) or may not be painful (if you have received sedatives).

Like a pacemaker, an ICD  has two parts: a pulse generator, including a battery  and  electronic  circuitry,  and  a system of coated  leads tipped with electrodes. Newer devices are as small as a pager. They are also designed to provide a controlled  burst of impulses, called overdrive pacing,  at the  first sign of ventricular  tachycardia.  If that  does  not restore  normal  heart rhythms,  the device delivers de?brillation shock.

The  devices make decisions on what type of therapy to give based on how fast the heart  rate is. The  devices are also equipped  to regulate bradycardia (slow heartbeat) if that occurs. They also have a memory to record  arrhythmic episodes  and do some internal  electrophysiologic testing.

In a person who has experienced prolonged ventricular  arrhythmia, the  ICD  is more  effective  than  antiarrhythmic drugs  at preventing sudden death. The device may also similarly prevent cardiac arrest in a person who is considered  at high risk of developing such arrhythmias. Before you are considered as a candidate for an ICD, your doctor must rule out other causes of the arrhythmia, such as a heart attack, myocar- dial ischemia  (inadequate  blood  ?ow to the  heart;  see page 161), or chemical imbalance and drug reactions,  which can be treated  in other ways.

How an ICD Is Implanted

The procedure for placing an ICD is very similar to that for a pacemaker (see page 273). At the hospital, you will be given a sedative and then a local anesthetic. The cardiologist or surgeon will make an incision in the skin and then tunnel the leads through blood vessels into your heart, or onto its surface. Then  he or she will tuck the ICD into a pouch of skin under the collarbone or somewhere above the waistline. The leads will be attached to the pulse generator. Electrophysiologic testing will be done to check out the device. The entire procedure  takes about 2 hours.

You will probably  stay in the hospital  overnight.  You may be prescribed some antiarrhythmic medications, too. These drugs may lessen the need for high-energy shocks from your ICD.  The  recovery time, the pain after the procedure,  and risks of the procedure  are very similar to those of a pacemaker.

After Implantation

After your ICD is installed, you will need to return to the doctor’s of?ce for monitoring every 1 to 3 months. Your doctor can evaluate the ICD function  electronically  by moving  a programming wand  over  your chest. By this means, he or she can determine what kinds of impulses have been delivered, whether  they worked, whether  they need modi?- cation, and how much energy is left in the battery.  When  the energy level in the battery is down to a predetermined level, you will be scheduled  for replacement  surgery.  The  battery  usually lasts from  3 to  5 years, depending on how many shocks it delivers. Usually, replacement surgery is somewhat simpler than the original implantation because the leads do not need to be replaced. Some ICDs can also be checked periodically by telephone.

Many people feel some apprehension about the possibility of receiv- ing unexpected de?brillation shocks. You may need to continue to take antiarrhythmia medications  to reduce the risk of needing a shock from the implanted  device. Some shocks are small, and some people don’t notice them. When  you do receive a stronger  shock, it may feel like a jolt, thump, or blow to the chest. Some people black out during periods of ?brillation,  so they don’t feel the shock; see “Living with an ICD,” next section, on driving if you have an implanted  ICD.  If someone  is touching you during the shock, he or she may feel a tremor, but will not be harmed by it in any way.

You and your doctor  can discuss what to do if your ICD  delivers a shock. Your doctor may tell you to call him or her if you feel a shock, or if you feel ill after the shock.

Apart from the discomfort of a sudden de?brillation shock, possible side effects of ICD placement include some sensitivity at the site of the implant,  especially in very slender  people;  very rare  problems  with infection;  and  some  cosmetic  issues (the  device is visible under  the skin). If you feel apprehension about the shocks or concern about your need for an ICD, ask your doctor about a support group, where you can talk with other ICD “users” and medical staff.

You will also be given an identi?cation card that  provides speci?c information about your ICD. Carry it with you at all times, and show it to health-care professionals and airport security.

Living with an ICD

As with a pacemaker, your ICD  can interact  with some devices in your environment with electromagnetic or radiofrequency ?elds. Review the interactions  with implantable  devices (see page 276), and talk to your doctor in detail about how devices in your environment, medical proce- dures, or your activities might affect your ICD.

Driving  is a major  consideration for a person  with an ICD.  Your ICD may take an interval of 5 to 15 seconds or longer to detect arrhythmias and deliver treatments, during which you might feel dizzy or even faint. Therefore, you are usually advised to avoid driving,  and other activities, such as piloting or scuba diving, that would put you and others at risk if you were  to  lose consciousness.  In  some  states,  these restrictions  are law. Review this issue with your doctor carefully. Some people who go for long periods without shock or symptoms are allowed to return  to driving, but only with the advice of a doctor.

Maze Surgery

In some people with chronic atrial ?brillation,  an operation  called the maze procedure  involves making a series of incision  lines within  the heart to create a maze that blocks electrical pathways through the heart muscle. This surgery is done in a person for whom medications, a pace- maker, or other  treatments have not been effective. A likely candidate might  be a person  with uncontrolled atrial ?brillation,  for whom the chief danger is that blood will pool in the upper chambers of the heart (the  atria); this pooling  increases  the  tendency  of the  blood  to clot, which could lead to a stroke. The  surgery may be performed  with cer- tain other  types of heart surgery to prevent atrial ?brillation  after the operation.

The procedure is major surgery, done with the patient under general anesthesia. The  surgeon must split the breastbone  to expose the heart and  transfer  the  functions  of the  heart  and  lungs  to  a heart-lung machine during the procedure.

The  surgeon makes a number  of small incisions in both the left and right  atria. These  incisions form a pattern  that  will direct  the heart’s electrical impulses into the ventricles and block extra impulses. As the incisions heal, scar tissue forms that cannot conduct electrical impulses,

so the new pathways are permanently  established.  The  surgery  takes about 3 hours. Sometimes a pacemaker is implanted,  too.

Recovery from maze surgery requires about 1 week in the hospital. You may need diuretics to prevent ?uid accumulation,  and antiplatelet medication  such as aspirin to prevent blood clots. You may experience pain from the chest incision, and fatigue for 2 to 3 months after surgery. Most people can go back to normal activities, including work, in about 3 months.

The  maze procedure  has been adapted to a less invasive technique, similar to a catheter-based ablation technique for atrial ?brillation. The technique allows the radiofrequency to be directed to the outside of the heart. This technique  is complementary to less-invasive catheter-based ways to perform ablation of atrial ?brillation  through the veins.