What is a pacemaker?

A pacemaker is a small device implanted in the chest to help control your heartbeat. It's used when the heart beats too quickly, too slowly or irregularly due to a heart attack, heart failure or other problem that has damaged the heart's natural electrical system. A pacemaker mimics that system by sending out painless electrical signals that stimulate heart muscle contraction – the first part of the heart's pumping action.

What are the benefits of a pacemaker?

A pacemaker can relieve the symptoms of a slow or unsteady heartbeat, such as:

  • Dizziness
  • Fainting episodes
  • Shortness of breath

For people with certain heart rhythm irregularities, pacemakers can be lifesaving.

How does a pacemaker work?

A pacemaker is battery powered. Most have two parts, the pulse generator and the lead. The pulse generator is a matchbox-sized metal container that holds the battery and electronics. The lead is a thin wire that conducts electrical signals.

Most pacemakers are placed under the skin of the chest and connected to the heart via one, two or three leads. But there are also leadless pacemakers, which are placed directly in the heart.

Pacemakers are usually implanted permanently. But, they're sometimes used as a temporary measure to stabilize heart rhythms in people recovering from a heart attack, heart surgery or a medication overdose that slowed their heart rate.