Treatments & Devices
Each individual heartbeat is actually a collection of several muscle movements spurred into action by electrical impulses.
The first electrical signal comes from the heart’s own natural pacemaker, the sinoatrial node, comprised of electrically active cells and located in the upper right heart chamber. This node sends a steady burst of electricity along a pathway through the heart’s upper chambers. The signals then travel to the electrical bridge – the atrioventricular node – between the upper and lower chambers and, finally, move to the lower chambers.
A problem at any point in the electrical pathway can wreak havoc with the regular beating of a heart. Luckily, an artificial pacemaker – a small, battery -operated device – can take over the role of the heart’s own electrical system, if necessary.
What is a Pacemaker?
Although it weighs just about an ounce, a pacemaker contains a powerful battery, electronic circuits and computer memory that together generate electronic signals. The signals, or pacing pulses, are carried along thin, insulated wires, or leads, to the heart muscle. The signals cause the heart muscle to begin the contractions that cause a heartbeat.
A pacemaker is implanted just below the collarbone in a procedure that takes about two hours. It is programmed to stimulate the heart at a pre-determined rate, and settings can be adjusted at any time. Routine evaluation, sometimes even via telephone, ensures the pacemaker is working properly and monitors battery life, which generally runs from five to ten years.
When is a Pacemaker Needed?
The most common reason for a pacemaker is a heartbeat that slows to an unhealthy rate, or bradycardia. A pacemaker resets the heart rate to an appropriate pace, ensuring adequate blood and oxygen are delivered to the brain and other parts of the body.
Types of Pacemakers
Three basic types exist to serve different purposes:
• Single-Chamber Pacemakers – In a single-chamber pacemaker, only one wire (pacing lead) is placed into a chamber of the heart. Sometimes it is the upper chamber, or atrium. Other times it is the lower chamber, or ventricle.
• Dual-Chamber Pacemakers – In dual chamber pacemakers, wires are placed in two chambers of the heart. One lead paces the atrium and one paces the ventricle. This approach more closely matches the natural pacing of the heart. This type of pacemaker can coordinate function between the atria and ventricles.
• Rate-Responsive Pacemakers – These have sensors that automatically adjust to changes in a person's physical activity.
• Other devices – Some devices, such as implantable cardioverter defibrillators (ICDs), designed primarily for other purposes, can function as pacemakers in certain situations.
When Are Pacemakers Used?
Pacemakers may be prescribed for a number of conditions, including:
• Bradycardia – a condition in which the heart beats too slowly, causing symptoms such as fatigue, dizziness or fainting spells. Bradycardia may be caused by the wear and tear of age or by conditions such as sick sinus syndrome (SSS) or heart block.
• Atrial fibrillation – a common heart rhythm disorder in which the upper chambers of the heart beat rapidly and chaotically. Sometimes people with atrial fibrillation can also have slow rhythms. Medicines used to control atrial fibrillation may result in slow rhythms which are treated by pacemakers.
• Heart failure – a condition in which the heartbeat is not sufficient to supply a normal volume of blood and oxygen to the brain and other parts of the body. A special pacemaker can be carefully programmed to increase the force of muscle contractions in the heart. This is called “biventricular pacing” or “resynchronization” therapy.
• Syncope – a condition best known as the common faint, is usually not serious. Some patients faint when their heart rhythm becomes very slow. For a small percentage of people who experience severe and frequent fainting spells, a pacemaker may prevent the heart rate from slowing to the point of fainting.
Sports and Your Pacemaker
Full-contact sports can damage a pacemaker.
Magnetic Resonance Imaging (MRI) tests employ powerful magnets to create images. If you are scheduled for an MRI test, you should make certain your doctor knows you have a pacemaker.
Electronic security systems, such as those common in airports, can pose problems if exposure is prolonged. Passing through such systems, even several times, does not pose a threat. However, patients with pacemakers should avoid the “wand” used in some security checks. Microwave ovens, cellular phones and electric blankets do not, as myth might have it, affect pacemaker functioning.
Common Questions About Pacemakers
What happens after the procedure?
You will be admitted overnight so your heart rate and rhythm. The morning after your implant, you will have a chest X-ray to insure the leads are in proper placement. Your device will be checked by the device clinic or a company representative to insure the device is at the optimal settings.
You will be shown how to take care of you wound site. Keep it clean and dry to prevent the chance of infection. After three to five days, you may take a shower. Look at the wound every day to make sure it is healing well.
Call your doctor if you see any of the following:
• Increased drainage, bleeding, or oozing from the insertion site.
• If the wound appears to be opening at the incision site.
• Redness, swelling or warmth around the site.
• Fever or chills
You will be given a temporary ID card before you leave the hospital. The card will have the following information:
• The type of the model of the device, the lead information, date of implant, and the physician who implanted the device.
You should receive a permanent cared from the pacemaker company in about three months. You should carry this card with you at all times.
Do I have any restrictions from moving around after the implant?
You will be able to move around normally.
You will have some restrictions with your arm on the side the pacemaker was placed:
Do not lift objects that weigh more than 10 pounds, including children and pets.
Do not raise your arm above your shoulder as determined by your physician.
Avoid pushing, pulling heavy objects such as shoveling, mowing the lawn
No golfing, tennis, or swimming for six weeks after the procedure.
Try to walk as much as possible for exercise.
Your doctor will tell you when you can go back to work and do strenuous activities.
Do cellular phones interfere with pacemakers?
The answer to this question depends on the type of cellular phone being used. Pacemakers are engineered to withstand interference from analog cellular phones which are being phased out. However, in some cases, digital cellular phones may interfere with pacemakers. It is best not to carry the phone in your shirt pocket on the same side as your phone. Use the phone on the opposite side from the device or use a head set.
How long does a pacemaker last?
Pacemakers can last anywhere from 5 to 10 years or more - on the average about seven years. Device longevity depends upon how hard the battery inside the pacemaker has to work. This is affected by how much energy is required to pace the heart and how the system is programmed. Thanks to ongoing research and development, the life of pacemakers continues to increase as their size decreases, making them more comfortable for people. Replacing a pacemaker may be done on an outpatient basis or may include an overnight stay in the hospital. Your length of stay will depend if the leads need to be changed or if only the device is changed out.
Will I feel the pacemaker?
At first, you may feel the weight of the pacemaker in your chest. However, over time, most people become accustomed to the pacemaker and forget it is there. The generator is small, about the size of two –three silver dollars placed on top of each other, and weighs about an ounce or less, depending on the manufacture and model of the device.
Are there different types of pacemakers?
There are different types of pacemakers:
• Single chamber pacemaker uses one lead in the upper chambers (atria) or lower chambers (ventricles) of the heart.
• Dual chamber pacemaker uses one lead in the atria and one lead in the ventricles of your heart.
• Cardiac resynchronization therapy (CRT) pacemaker uses three leads: one placed in the right atrium, one placed in the right ventricle, and one placed in the left ventricle (via the coronary sinus vein).
Your physician will be able to explain which device is best for you.
Can patients with a pacemaker live an active life style such as tennis, skiing, jogging or have sexual relationships?
Typically, pacemaker patients can continue to lead active lives. If you did a certain activity before, more likely than not, you'll be able to continue that activity after pacemaker implantation. In fact, you should be able to participate in most activities. Because people may have more energy after the pacemaker is implanted, they may be able to do more than they have been able to do for some time. If there are special activities that a patient would like to participate in, this needs to be discussed with the physician prior to the procedure, as it may affect the device that is selected and how it is implanted.
What is EMI?
EMI means electromagnetic interference. Certain types of electrical or magnetic energy can interfere with your pacemaker’s operation. You should do your best to avoid major sources of EMI.
What causes EMI?
EMI or electromagnetic interference can be caused by:
• Electrical appliances in poor condition or not grounded correctly
• Electrical equipment that produces a great deal of energy, like industrial generators or car alternators
• Certain devices, notably arc-welders
• Medical equipment including MRI devices, therapeutic radiation, and TENS (pain-control devices)
What electrical equipment is safe to use?
Most home appliances in good working order are safe to use. This includes microwave ovens, blenders, toasters, electric knives, ultrasonic dental cleaners, televisions, VCRs, electric blankets, electric stoves, and garage door openers.
Office equipment and most medical equipment are safe to use. The pacemaker will work properly during chest and dental x-rays, diagnostic ultrasound, CT scan, mammography, and fluoroscopy.
What should I do if I am near a source of EMI?
In most cases you can just walk away from the EMI source or turn it off. At airports, show the security personnel your pacemaker identification card so that you do not have to walk through the metal detector. If you feel symptoms such as lightheadedness or palpitations after being near an EMI source, contact your doctor.
Source: © Heart Rhythm Society