A pacemaker is a small device that's placed under the skin of your chest or abdomen to help control abnormal heart rhythms.
A pacemaker uses low-energy electrical pulses to correct faulty electrical signaling in the heart causes arrhythmias. Pacemakers can:
Speed up a slow heartbeat
Help end an abnormal and fast rhythm (only in implantable cardioverter defibrillator/pacemaker combination devices)
Make sure the ventricles contract normally if the atria are in a state of atrial fibrillation
Coordinate the electrical signaling between the upper and lower chambers of the heart
Coordinate the electrical signaling between the ventricles (cardiac resynchronization therapy used in heart failure)
Monitor and record your heart's electrical activity and the rhythm of your heartbeat. Newer pacemakers can monitor your blood temperature, breathing rate, and other factors and adjust your heart rate to changes in your activity.
A pacemaker consists of a battery, a computerized generator, and wires with electrodes on one end. The battery powers the generator, and a thin metal box surrounds both it and the generator. The wires connect the generator to the heart.
The pacemaker's generator sends the electrical pulses that correct or set your heart rhythm. A computer chip figures out what types of electrical pulses to send to the heart and when those pulses are needed. To do this, the computer chip uses the information it receives from the wires connected to the heart. It also may use information from sensors in the wires that detect your movement, blood temperature, breathing, or other factors that indicate your level of physical activity. That way, it can make your heart beat faster when you exercise.
The computer chip also records your heart's electrical activity and heart rhythms. Your doctor will use these recordings to set your pacemaker so it works better at making sure you have a normal heart rhythm. Your doctor can program the computer in the pacemaker without having to use needles or directly contacting the pacemaker.
A pacemaker may be helpful if:
Aging or heart disease damages your sinus node's ability to set the correct pace for your heartbeat. Such damage can make your heart beat too slow, or it can cause long pauses between heartbeats. The damage also can cause your heart rhythm to alternate between slow and fast.
You need to take certain heart medicines (such as beta blockers), but these medicines slow down your heartbeat too much.
The electrical signals between your heart's upper and lower chambers are partially or completely blocked or slowed down (this is called heart block). Aging, damage to the heart from a heart attack, or other heart conditions can prevent electrical signals from reaching all the heart's chambers.
You often faint due to a slow heartbeat.
You need help regulating your heartbeat after having a medical procedure to treat atrial fibrillation.
You have heart muscle problems that cause electrical signals to travel through your heart muscle too slow. (Your pacemaker will provide cardiac resynchronization therapy for this problem.)
To decide whether a pacemaker will benefit you, your doctor will consider any symptoms you have of an irregular heartbeat, 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 won't be recommended unless your heart tests show that you have irregular heartbeats.
Other important notes
Pacemaker surgery is usually done in a hospital or special heart treatment laboratory. You will be given medicine to help you relax. The surgery takes just a few hours, but you will stay in the hospital overnight so your doctor can monitor your heart rhythm and make sure your pacemaker is working properly.
Problems from pacemaker surgery are rare. Most people can return to normal activities within a few days.
Your doctor may ask you to avoid any vigorous exercise or heavy lifting for a short period 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.
Have your pacemaker checked 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 have to be replaced every 5 to 15 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 you need to replace your pacemaker or its wires.