Home > Encyclopedia of Surgery > Pacemakers

Definition

A pacemaker is a surgically implanted electronic device that regulates a cardiac arrhythmia.

Pacemakers are most frequently prescribed when the heartbeat decreases under 60 beats per minute at rest (severe symptomatic bradycardia). They are also used in some cases to slow a fast heart rate over 120 beats per minute at rest (tachycardia).

Demographics

The population for pacemaker implant is not limited by age, sex, or race. Over 100,000 pacemakers are implanted per year in the United States. The occurrence is more frequent in the elderly with over 85% of implants received by those over age 65. A history of myocardial infarction (heart attack), congenital defect, or cardiac transplant also increases the likelihood of pacemaker implant.