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 Cardiac, Other Heart and Vascular Diseases 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 Cardiac, Other Heart and Vascular Diseases may get pacemakers. Pacemakers also are sometimes implanted after heart transplants.
This answer from the National Heart, Lung and Blood Institute has been reviewed and/or edited by Dr. William D. Knopf.