Artificial pacemaker

A device that uses electrical impulses to regulate the heart rhythm or to reproduce that rhythm. An internal pacemaker is one in which the electrodes into the heart, the electronic circuitry and the power supply are 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). Pacemakers may 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. History: The internal pacemaker was invented by Wilson Greatbatch in 1958. While building an oscillator to record heart sounds, he installed a resistor with the wrong resistance in the unit. It began to give off a steady electrical pulse. Greatbatch realized that the device could be used to regulate the heart and hand-crafted the world's first implantable pacemaker. Greatbatch later invented the corrosion-free lithium battery to power the pacemaker.

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artificial cardiac pacemaker a device that uses electrical impulses to reproduce or regulate the rhythms of the heart. Battery-driven and connected to the heart by leads and electrodes, it may be temporary or permanent and is inserted transvenously, transcutaneously, epicardially, or via the esophagus or coronary artery. Most pacemakers are either triggered or inhibited to modify output by sensing the intracardiac potential of one or more cardiac chambers; they have some degree of programmability and may also have antitachycardia functions. A five letter code is used to categorize pacemakers by their combinations of these features; see table. Popularly called pacemaker.

*NASPE, North American Society of Pacing and Electrophysiology; BPEG, British Pacing and Electrophysiology Group.

†Positions I through III describe only antibradyarrhythmia functions of the pacemaker.

Pacemaker lead (arrow) terminating in the right ventricle.