What is a ventricular demand pacemaker?

Pacemaker function. It is a way for a pacemaker to only pace your heart when your heart rate is below a set rate (usually 60 beats per minute).
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....