Dr Simon Kennon MB ChB, FRCP, MD Consultant Cardiologist


The heart is essentially a pump, made of muscle, which is controlled by electrical signals. Sometimes these signals are disrupted for a number of reasons, including heart tissue damage, infection of heart tissue, medications, complications of heart surgery and so on. If this happens, a number of potentially dangerous heart conditions may follow including heart block, where your heart beats irregularly, abnormally fast or abnormally slow and cardiac arrest when the heart stops beating altogether.

What is a pacemaker?

A pacemaker is a small device that's placed in the chest or abdomen to help control abnormal heart rhythms. It uses electrical pulses to prompt the heart to beat at a normal rate.

Most pacemakers are very reliable and comfortable. They're smaller than an average matchbox and weigh about 20 to 50 grams. A pacemaker sits just under your collarbone and will have one or more leads which are placed into your heart through a vein.

The job of a pacemaker is to artificially take over the role of your heart's natural pacemaker, the sinus node. Electrical impulses are sent by the pacemaker to stimulate your heart to contract and produce a heartbeat. Most pacemakers work only when they’re needed - on demand. Some pacemakers send out impulses all of the time (fixed rate).

How are pacemakers fitted?

Pacemakers are fitted under a local anaesthetic with sedation, so you’ll feel very sleepy. After the pacemaker is fitted, you’ll usually stay overnight in hospital and your pacemaker will be checked thoroughly before you leave. Serious complications from pacemakers are very unusual.


It’s normal to feel tired for a few days afterwards, but most people find that they can return to their normal lifestyle fairly quickly. You’re not allowed to drive a car for at least a week after your pacemaker is fitted.