The pacemaker is an implantable medical device that restores the heartbeat to a normal rate, and is most often used for relieving the symptoms of bradycardia, a type of heart condition in which the heart beats at less than the average 60 beats per minute.
A pacemaker stimulates the heart muscle with precisely timed discharges of electricity that cause the heart to beat in a manner very similar to a naturally occuring heart rhythm. Pacemakers are usually implanted in a routine, outpatient surgical procedure.
Pacemakers come in many shapes and sizes, all of which are small and lightweight (approximately 22-50 grams.) Depending on the patient's heart condition, the physician will prescribe the number of chambers to be paced and a specific kind of pacing. There are two types of pacemakers, single-chamber and dual-chamber. Single-chamber pacemakers paces either the right atrium of the right ventricle of the heart with one lead. A dual-chamber pacemaker paces both the right atrium and right ventricle of the heart. The dual-chamber pacemaker is the most common type of pacemaker implanted today.
Pacemakers also vary on their type of pacing. A rate-responsive pacemaker is needed when a heart cannot increase its rate according to a person's needs. It responds depending on a person's level of activity, respiration or other factors.
The Pacemaking Industry
Each year, more than 400,000 pacemakers are implanted, extending and enhancing the quality life of patients. Sales of pacemaker implantable devices exceed $5 billion per year with the United States as the leader in sales.
For more information on pacemakers and pacemaking, please visit the Medtronic web site at: http://www.medtronic.com.
Photo credit: "The Making of the Pacemaker, Celebrating a Lifesaving Invention" by Wilson Greatbatch. Published 2000 by Prometheus Books.
