A pacemaker is a small device, about the size of a pocket watch, that's placed under the skin near your heart to help control your heartbeat. People may need a pacemaker for a variety of reasons — mostly due to one of a group of conditions called arrhythmias, in which the heart's rhythm is abnormal.
Normal aging of the heart may disrupt your heart rate, making it beat too slowly. Heart muscle damage resulting from a heart attack is another common cause of disruptions of your heartbeat. Some medications can affect your heart rate as well. For some, genetic conditions cause an abnormal heart rate. Regardless of the underlying cause of an abnormal heart rate, a pacemaker may fix it.
A pacemaker can often be implanted in your chest with a minor surgery. You may need to take some precautions in your daily life after your pacemaker is installed.
Why it's done
Pacemakers are implanted to help control your heartbeat. They can be implanted temporarily to treat a slow heartbeat after a heart attack, surgery or overdose of medication. Pacemakers can also be implanted permanently to correct a slow heartbeat (bradycardia) or, in some cases, to help treat heart failure. To understand how a pacemaker works, it helps to know how your heart beats.
How your heart beats
For your heart to function properly, the heart's chambers must work in a coordinated fashion. Your heart must also beat at an appropriate rate — normally from 60 to 100 beats a minute in resting adults. If your heart beats too slowly or too rapidly, not enough blood flows through your body, leading to fatigue, fainting, shortness of breath, confusion, and other signs and symptoms.
Your heart's electrical system controls the chambers' pumping action. A normal heartbeat begins in your right atrium, in the sinus node. This cluster of cells — your natural pacemaker — acts like a spark plug, generating regular electrical impulses that travel through specialized muscle fibers.
When an electrical impulse reaches both the right and left atria, they contract and squeeze blood into the ventricles. After a split-second delay to allow the ventricles to fill, the impulse reaches the ventricles, making them contract and pump blood to the rest of your body.
What a pacemaker does
Pacemakers monitor your heartbeat and, if it's too slow, the pacemaker will speed up your heart rate by sending electrical signals to your heart. In addition, most pacemakers have sensors that detect body motion or breathing rate, which signals the pacemaker to increase your heart rate during exercise to meet your body's increased need for blood and oxygen.
Chambers of the heart
Working as a precisely coordinated team, the four chambers of your heart — two ventricles and two atria — keep blood flowing properly through your heart and body. ...
The conduction system
Your heart's natural pacemaker — the sinus node — produces electrical impulses that prompt your heart to beat. ...
Your heart's natural pacemaker — the sinus node — produces electrical impulses to stimulate your heart to beat. If these impulses are disrupted, you may need an artificial pacemaker. ...
Complications from having surgery to implant your pacemaker are uncommon, but could include:
Life-threatening complications of pacemaker implantation are rare.
How you prepare
Before your doctor decides if you need a pacemaker, you'll have several tests done to find out the cause of your irregular heartbeat. These could include:
What you can expect
During the procedure
During surgery, a flexible, insulated wire (lead) is inserted into a major vein under or near your collarbone and guided to your heart with the help of X-ray images. One end of the lead (the electrode) is secured to your heart's right ventricle, while the other end is attached to the pulse generator, which is usually implanted under the skin beneath your collarbone.
In many cases, another lead is secured to your heart's upper right chamber (atrium) to keep your heart pumping in a coordinated manner. This is called a dual chamber pacemaker system because both the right atrium and right ventricle are stimulated in sequence.
After the procedure
After that, you'll have your pacemaker checked via telephone every few months. You connect to a phone line with either a transmitter attached to wristbands on each of your arms or a wand placed over the pacemaker. These devices send pacemaker information to your doctor's office. A technician on the other end of the line checks your heart rate and rhythm and evaluates your pacemaker's function and remaining battery life.
After your procedure to implant your pacemaker, your doctor may recommend that you avoid vigorous exercise or heavy lifting for about a month. You may have some aches and pains near the area where your pacemaker was implanted. These pains can be relieved with over-the-counter medicines, such as acetaminophen (Tylenol, others) or ibuprofen (Motrin, Advil, others), but talk to your doctor before taking any pain relievers.
Devices that are unlikely to interfere with your pacemaker include microwave ovens, televisions and remote controls, radios, toasters, electric blankets, electric shavers and electric drills.
Once your pacemaker is implanted, it should last five to 10 years, which is the average battery life. When a pacemaker's battery wears out, the entire pacemaker's pulse generator is replaced, and you'll need another procedure to fix your device. The leads of your pacemaker can be left in place, and the procedure to change your pacemaker's battery is often quicker and requires less recovery time than the procedure to first implant your pacemaker.
Pacemakers are a standard treatment for many conditions affecting your heart's electrical system. By preventing a slow heart rate, pacemakers can treat symptoms, such as fatigue, lightheadedness and fainting. Because most of today's pacemakers automatically adjust your heart rate to match your level of physical activity, they can allow you to resume a more active lifestyle.
Pacemakers and end-of-life issues
If you have a pacemaker implanted and are concerned about turning off your pacemaker, talk to your doctor. You may also want to talk to family members or another person designated to make medical decisions for you about what you'd like to do in end-of-life care situations.
Last Updated: 2010-10-15
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