A pacemaker is a small device that's placed in the chest or abdomen to help control abnormal heart rhythms. This device uses low-energy electrical pulses to prompt the heart to beat at a normal rate.
Pacemakers can be temporary or permanent. Temporary pacemakers are used to treat temporary heartbeat problems, such as a slow heartbeat that's caused by a heart attack, heart surgery, or an overdose of medicine. Temporary pacemakers also are used during emergencies. They're used until a permanent pacemaker can be implanted or until the temporary condition goes away. If you have a temporary pacemaker, you'll stay in a hospital as long as the device is in place. Permanent pacemakers are used to control long-term heart rhythm problems. This article mainly discusses permanent pacemakers, unless stated otherwise. Doctors also treat arrhythmias with another device called an implantable cardioverter defibrillator (ICD). An ICD is similar to a pacemaker. However, besides using low-energy electrical pulses, an ICD also can use high-energy electrical pulses to treat certain dangerous arrhythmias.
The illustration shows a cross-section of a chest with a pacemaker. Figure A shows the location and general size of a double-lead, or dual-chamber, pacemaker in the upper chest. The wires with electrodes are inserted into the heart's right atrium and ventricle through a vein in the upper chest. Figure B shows the electrode electrically stimulating the heart muscle. Figure C shows the location and general size of a single-lead, or single-chamber, pacemaker in the upper chest. The wire with the electrode is inserted into the heart's right ventricle through a vein in the upper chest.
- Pacemakers can relieve some arrhythmia symptoms, such as fatigue (tiredness) and fainting. A pacemaker also can help a person who has abnormal heart rhythms resume a more active lifestyle.
- Before recommending a pacemaker, your doctor will consider any arrhythmia symptoms you have, such as dizziness, unexplained fainting, or shortness of breath. He or she also will consider whether you have a history of heart disease, what medicines you're currently taking, and the results of heart tests.
- A pacemaker consists of a battery, a computerized generator, and wires with sensors called electrodes on one end. The electrodes detect your heart's electrical activity and send data through the wires to the computer in the generator.
- If your heart rhythm is abnormal, the computer will direct the generator to send electrical pulses to your heart. The pulses then travel through the wires to reach your heart.
- Newer pacemakers also can monitor your blood temperature, breathing, and other factors and adjust your heart rate to changes in your activity.
- Placing a pacemaker requires minor surgery. The surgery usually is done in a hospital or special heart treatment laboratory. You'll be given medicine just before the surgery that will help you relax and may make you sleepy.
- The surgery takes just a few hours, but you'll stay in the hospital overnight so your health care team can check your heartbeat and make sure your pacemaker is working properly.
- Complications from pacemaker surgery are rare. Most people can return to their normal activities within a few days.
- Your doctor may ask you to avoid vigorous exercise or heavy lifting for about a month after your surgery. After you have fully recovered from surgery, discuss with your doctor how much and what kinds of physical activity are safe for you.
- Once you have a pacemaker, you have to avoid close or prolonged contact with electrical devices or devices that have strong magnetic fields. You also need to avoid certain medical procedures that can disrupt your pacemaker.
- Let all of your doctors, dentists, and medical technicians know that you have a pacemaker. Your doctor can give you a card that states what kind of pacemaker you have. Carry this card in your wallet. You may want to consider wearing a medical ID bracelet or necklace that explains that you have a pacemaker.
- Your doctor will want to check your pacemaker regularly. Some pacemaker functions can be checked remotely through a telephone call or a computer connection to the Internet. Your doctor may ask you to come to his or her office to check your pacemaker.
- Pacemaker batteries last between 5 and 15 years (average 6 to 7 years), depending on how active your pacemaker is. The wires of your pacemaker also may need to be replaced eventually. Your doctor can tell you whether your pacemaker or its wires need to be replaced.
Who Needs a Pacemaker?
Doctors recommend pacemakers for a number of reasons. The most common reasons are bradycardia and heart block. Bradycardia is a slower than normal heartbeat. Heart block is a problem with the heart's electrical system. The disorder occurs when an electrical signal is slowed or disrupted as it moves through the heart. Heart block can happen as a result of aging, damage to the heart from a heart attack, or other conditions that interfere with the heart's electrical activity. Certain nerve and muscle disorders also can cause heart block, including muscular dystrophy. Your doctor also may recommend a pacemaker if:
- Aging or heart disease damages your sinus node's ability to set the correct pace for your heartbeat. Such damage can cause slower than normal heartbeats or long pauses between heartbeats (as discussed above). The damage also can cause your heart to alternate between slow and fast rhythms. This condition is called sick sinus syndrome.
- You've had a medical procedure to treat an arrhythmia called atrial fibrillation. A pacemaker can help regulate your heartbeat after the procedure.
- You need to take certain heart medicines, such as beta blockers. These medicines may slow your heartbeat too much.
- You faint or have other symptoms of a slow heartbeat. For example, this may happen if the main artery in your neck that supplies your brain with blood is sensitive to pressure. Just quickly turning your neck can cause your heart to beat slower than normal. If that happens, not enough blood may flow to your brain, causing you to feel faint or collapse.
- You have heart muscle problems that cause electrical signals to travel too slowly through your heart muscle. (Your pacemaker may provide cardiac resynchronization therapy for this problem.)
- You have long QT syndrome, which puts you at risk for dangerous arrhythmias.
Children, adolescents, and people who have certain types of congenital heart disease may get pacemakers. Pacemakers also are sometimes implanted after heart transplants. Before recommending a pacemaker, your doctor will consider any arrhythmia symptoms you have, such as dizziness, unexplained fainting, or shortness of breath. He or she also will consider whether you have a history of heart disease, what medicines you're currently taking, and the results of heart tests.
A number of tests are used to detect arrhythmias. Your doctor may recommend some or all of these tests.
An EKG is a simple, painless test that detects and records the heart's electrical activity. The test shows how fast the heart is beating and its rhythm (steady or irregular).An EKG also records the strength and timing of electrical signals as they pass through each part of the heart. The test can help diagnose bradycardia and heart block (the most common reasons for needing a pacemaker).A standard EKG only records the heartbeat for a few seconds. It won't detect arrhythmias that don't happen during the test.To diagnose heart rhythm problems that come and go, your doctor may have you wear a portable EKG monitor. The two most common types of portable EKGs are Holter and event monitors.
Holter and Event Monitors
A Holter monitor records the heart's electrical activity for a full 24- or 48-hour period. You wear one while you do your normal daily activities. This allows the monitor to record your heart for a longer time than a standard EKG. An event monitor is similar to a Holter monitor. You wear an event monitor while doing your normal activities. However, an event monitor only records your heart's electrical activity at certain times while you're wearing it. For many event monitors, you push a button to start the monitor when you feel symptoms. Other event monitors start automatically when they sense abnormal heart rhythms.You may wear an event monitor for 1 to 2 months, or as long as it takes to get a recording of your heart during symptoms.
Echocardiography (echo) uses sound waves to create a moving picture of your heart. The test provides information about the size and shape of your heart and how well your heart chambers and valves are working.Echo also can identify areas of poor blood flow to the heart, areas of heart muscle that aren't contracting normally, and injury to the heart muscle caused by poor blood flow.
During an electrophysiology study, a thin, flexible wire is passed through a vein in your groin (upper thigh) or arm to your heart. The wire records the heart's electrical signals.Your doctor uses the wire to electrically stimulate your heart. This allows him or her to see how your heart's electrical system responds. The electrical stimulation helps pinpoint where the heart's electrical system is damaged.
Some heart problems are easier to diagnose when your heart is working hard and beating fast.During stress testing, you exercise (or are given medicine if you're unable to exercise) to make your heart work hard and beat fast while heart tests, such as an EKG or echo, are done.
How Does a Pacemaker Work?
A pacemaker system consists of a battery, a computerized generator, and wires with sensors called electrodes on one end. The battery powers the generator, and both are surrounded by a thin metal box. The wires connect the generator to the heart. A pacemaker monitors and helps control your heartbeat. The electrodes detect your heart's electrical activity and send data through the wires to the computer in the generator. If your heart rhythm is abnormal, the computer will direct the generator to send electrical pulses to your heart. The pulses then travel through the wires to reach your heart. Newer pacemakers also can monitor your blood temperature, breathing, and other factors and adjust your heart rate to changes in your activity. The pacemaker's computer also records your heart's electrical activity and heart rhythm. Your doctor will use these recordings to adjust your pacemaker so it works better for you. Your doctor can program the pacemaker's computer with an external device. He or she doesn't have to use needles or have direct contact with the pacemaker. Pacemakers have one to three wires that are each placed in different chambers of the heart.
- The wires in a single-chamber pacemaker usually carry pulses between the right ventricle (the lower right chamber of your heart) and the generator.
- The wires in a dual-chamber pacemaker carry pulses between the right atrium (the upper right chamber of your heart) and the right ventricle and the generator. The pulses help coordinate the timing of these two chambers' contractions.
- The wires in a biventricular pacemaker carry pulses between an atrium and both ventricles and the generator. The pulses help coordinate electrical signaling between the two ventricles. This type of pacemaker also is called a cardiac resynchronization therapy (CRT) device.
Types of Pacemaker Programming
The two main types of programming for pacemakers are demand pacing and rate-responsive pacing.A demand pacemaker monitors your heart rhythm. It only sends electrical pulses to your heart if your heart is beating too slow or if it misses a beat. A rate-responsive pacemaker will speed up or slow down your heart rate depending on how active you are. To do this, the rate-responsive pacemaker monitors your sinus node rate, breathing, blood temperature, and other factors to determine your activity level. Most people who need pacemakers to continually set the pace of their heartbeats have rate-responsive pacemakers.
What To Expect During Pacemaker Surgery
Placing a pacemaker requires minor surgery. The surgery usually is done in a hospital or special heart treatment laboratory. Before the surgery, an intravenous (IV) line will be inserted into one of your veins. Medicine will be given through the IV line to help you relax. The medicine also may make you sleepy. Your doctor will give you medicine to numb the area where he or she will put the pacemaker so you don't feel any pain. Your doctor also may give you antibiotics to prevent infection.First, your doctor will place a needle in a large vein, usually near the shoulder opposite your dominant hand. Your doctor will then use the needle to thread the pacemaker wires into the vein and to the correct place in your heart.An x-ray "movie" of the wires as they pass through your vein and into your heart will help your doctor place them. Once the wires are in place, your doctor will make a small cut into the skin of your chest or abdomen. He or she will then slip the pacemaker's small metal box through the cut, place it just under your skin, and connect it to the wires that lead to your heart. The box contains the pacemaker's battery and generator. Once the pacemaker is in place, your doctor will test it to make sure it works properly. He or she will then sew up the cut. The entire surgery takes a few hours.
What To Expect After Pacemaker Surgery
Expect to stay in the hospital overnight so your health care team can check your heartbeat and make sure your pacemaker is working properly. You'll probably have to arrange for a ride to and from the hospital because your doctor may not want you to drive yourself.For a few days to weeks after surgery, you may have pain, swelling, or tenderness in the area where your pacemaker was placed. The pain usually is mild, and over-the-counter medicines often can relieve it. Talk to your doctor before taking any pain medicines. Your doctor may ask you to avoid vigorous activities and heavy lifting for about a month after pacemaker surgery. Most people return to their normal activities within a few days of having the surgery.
What Are the Risks of Pacemaker Surgery?
Your chance of having any problems from pacemaker surgery is very low. If problems do occur, they may include:
- Swelling, bleeding, bruising, or infection in the area where the pacemaker was placed
- Blood vessel or nerve damage
- A collapsed lung
- A bad reaction to the medicine used during the procedure
How Will a Pacemaker Affect My Lifestyle?
Once you have a pacemaker, you have to avoid close or prolonged contact with electrical devices or devices that have strong magnetic fields. Devices that can interfere with a pacemaker include:
- Cell phones and MP3 players (for example, iPods)
- Household appliances, such as microwave ovens
- High-tension wires
- Metal detectors
- Industrial welders
- Electrical generators
These devices can disrupt the electrical signaling of your pacemaker and stop it from working properly. You may not be able to tell whether your pacemaker has been affected. How likely a device is to disrupt your pacemaker depends on how long you're exposed to it and how close it is to your pacemaker. To be on the safe side, some experts recommend not putting your cell phone or MP3 player in a shirt pocket over your pacemaker (if the devices are turned on).You may want to hold your cell phone up to the ear that's opposite the site where your pacemaker was implanted. If you strap your MP3 player to your arm while listening to it, put it on the arm that's farther from your pacemaker. You can still use household appliances, but avoid close and prolonged exposure, as it may interfere with your pacemaker. You can walk through security system metal detectors at your normal pace. You also can be checked with a metal detector wand as long as it isn't held for too long over your pacemaker site. You should avoid sitting or standing close to a security system metal detector. Notify airport screeners if you have a pacemaker. Stay at least 2 feet away from industrial welders or electrical generators.Some medical procedures can disrupt your pacemaker. These procedures include:
- Magnetic resonance imaging, or MRI
- Shock-wave lithotripsy to get rid of kidney stones
- Electrocauterization to stop bleeding during surgery
Let all of your doctors, dentists, and medical technicians know that you have a pacemaker. Your doctor can give you a card that states what kind of pacemaker you have. Carry this card in your wallet. You may want to consider wearing a medical ID bracelet or necklace that states that you have a pacemaker.
In most cases, having a pacemaker won't limit you from doing sports and exercise, including strenuous activities. You may need to avoid full-contact sports, such as football. Such contact could damage your pacemaker or shake loose the wires in your heart. Ask your doctor how much and what kinds of physical activity are safe for you.
Your doctor will want to check your pacemaker regularly (about every 3 months). Over time, a pacemaker can stop working properly because:
- Its wires get dislodged or broken
- Its battery gets weak or fails
- Your heart disease progresses
- Other devices have disrupted its electrical signaling
To check your pacemaker, your doctor may ask you to come in for an office visit several times a year. Some pacemaker functions can be checked remotely through a telephone call or a computer connection to the Internet. Your doctor also may ask you to have an EKG (electrocardiogram) to check for changes in your heart's electrical activity.
Pacemaker batteries last between 5 and 15 years (average 6 to 7 years), depending on how active the pacemaker is. Your doctor will replace the generator along with the battery before the battery starts to run down. Replacing the generator/battery is less-involved surgery than the original surgery to implant the pacemaker. The wires of your pacemaker also may need to be replaced eventually. Your doctor can tell you whether your pacemaker or its wires need to be replaced when you see him or her for followup visits.
Reference: Heart Lung and Blood Institute (NHLBI)
Last updated May 2, 2017