pacemaker
Americannoun
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Medicine/Medical. an electronic device implanted beneath the skin for providing a normal heartbeat by electrical stimulation of the heart muscle, used in certain heart conditions.
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Anatomy, Physiology. any specialized tissue that governs a rhythmic or cyclic biological activity, as the sinoatrial node of the heart that controls heartbeat.
noun
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a person, horse, vehicle, etc, used in a race or speed trial to set the pace
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a person, an organization, etc, regarded as being the leader in a particular field of activity
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Also called: cardiac pacemaker. a small area of specialized tissue within the wall of the right atrium of the heart whose spontaneous electrical activity initiates and controls the beat of the heart
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Also called: artificial pacemaker. an electronic device for use in certain cases of heart disease to assume the functions of the natural cardiac pacemaker
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Any of several usually miniaturized and surgically implanted electronic devices used to stimulate or regulate contractions of the heart muscle. Electrodes attached to the heart muscle conduct electrical signals generated from the pacemaker, which either provides constant electrical stimuli to regularize the heartbeat (fixed-rate pacemakers) or provides a stimulus only when electrical activity within the heart is abnormal (demand pacemakers). Pacemakers are used in the treatment of various arrhythmias.
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A part of the body, such as the specialized mass of cardiac muscle fibers of the sinoatrial node, that sets the pace or rhythm of physiological activity.
Other Word Forms
Derived Forms
Etymology
Origin of pacemaker
Explanation
A pacemaker is a medical device that controls a person's heartbeat. A patient only has a pacemaker implanted when his own heart isn't working well on its own. The human heart has a natural pacemaker that makes it beat at an appropriate rate to keep blood flowing throughout the body. Sometimes it doesn't work right, because of some kind of blockage or other problem that causes the heart to beat too slowly. In these cases, cardiologists — or heart doctors — will often surgically implant an electronic pacemaker as a replacement. Pacemaker research began in 1899, but it wasn't until 1958 that the first patients received these lifesaving devices.
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
From cornflakes to the pacemaker, some of our most beloved—and useful—products were born of blunders.
From The Wall Street Journal • Apr. 5, 2026
Eleven U.S. innovations, such as cornflakes, the implantable pacemaker and the microwave, were born from accidental discoveries.
From The Wall Street Journal • Apr. 4, 2026
Investigators are now using a device that might be able to detect Bluetooth signals coming from her pacemaker, law enforcement sources told CBS.
From BBC • Feb. 18, 2026
At 02:28, the app on her pacemaker, an implanted cardiac device, disconnected from her phone.
From BBC • Feb. 10, 2026
Regina was about to have a pacemaker implanted.
From "Endgame" by Frank Brady
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Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.