What is the function of pacemakers?

Devices for rhythm: Pacemakers are medical devices implanted under the skin and connected to leads inserted through veins into the chambers of the heart. By sending out a small electrical impulse the pacemaker can restore heart rhythm. The most common use for a pacemaker is for a very slow heart beat to restore rhythm. They may be either single or double lead pacemakers determined by patient need.

Pacemaker: A pacemaker is an electronic device which uses a lead as an antenna to sense the heart's electrical activity. It uses the same lead(s) to deliver a small electrical impulse to the heart to make it contract if the heart isn't going as fast as the device was programmed to maintain. Pacemakers both sense heart activity and pace it to produce activity. They maintain heart rate. Other things too....