Pacemaker, internal

Pacemaker, internal: A pacemaker sets the heart rate. An artificial pacemaker is a device that does this. It uses electrical impulses to regulate the heart rhythm or reproduce that rhythm. An internal pacemaker is one in which the electrodes into the heart, the electronic circuitry and the power supply are all implanted (internally) within the body. Although there are different types of pacemakers, all are designed to treat bradycardia, a heart rate that is too slow. Some pacemakers function continuously and stimulate the heart at a fixed rate or at an increased rate during exercise. A pacemaker can also be programmed to detect too long a pause between heartbeats and then stimulate the heart. The implantable artificial pacemaker was invented by Wilson Greatbatch in 1958.