cardiac pacemaker

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Related to cardiac pacemaker: artificial cardiac pacemaker


1. an object or substance that controls the rate at which a certain phenomenon occurs.
3. in biochemistry, a substance whose rate of reaction sets the pace for a series of interrelated reactions.
artificial pacemaker an electronic cardiac pacemaker that has a pulse generator to generate an extrinsic electrical impulse, causing the heart muscle to depolarize and then contract; its rate is preset regardless of the heart's intrinsic activity. It can be either temporary (transcutaneous, transvenous, or epicardial) or implanted.
asynchronous pacemaker an implanted pacemaker that delivers stimuli at a fixed rate, independent of any atrial or ventricular activity; this type is now rarely used except to initiate or terminate some tachycardias.
AV sequential pacemaker an implanted pacemaker with dual chamber pacing that maintains the atrial part of ventricular filling by stimulating the atrium if it does not respond at the proper interval after ventricular activity; used for patients with abnormal sinus node function or decreased atrioventricular conduction.
cardiac pacemaker a small mass of specialized muscle tissue in the heart that sets a rhythm of contraction and relaxation for the other parts of the heart, resulting in the heartbeat. Usually the pacemaker site is the sinoatrial node, near the junction with the superior vena cava. The normal rhythm, 60 to 100 contractions per minute, increases during physical or emotional stress and decreases during rest. The pace varies from person to person and is affected by abnormal conditions such as heart injuries and generalized infections. If the normal pacemaker fails to function, its regulating task may be taken over by another small mass of special muscular tissue, the atrioventricular node.
DDD pacemaker dual chamber pacemaker.
demand pacemaker an artificial pacemaker that activates only when it receives sensations indicating a lack of adequate spontaneous rhythm by the heart. It thus avoids competition with the patient's own natural pacemaker.
diaphragmatic pacemaker phrenic pacemaker.
dual chamber pacemaker an implanted pacemaker having two leads, one in the atrium and one in the ventricle, so that electromechanical synchrony between the chambers can be approximated. Called also DDD pacemaker.
A dual chamber pacemaker senses and paces in both the atrium and the ventricle.
ectopic pacemaker any biological cardiac pacemaker other than the sinoatrial node; under normal conditions it is not active.
electronic pacemaker artificial pacemaker.
epicardial pacemaker a temporary pacemaker whose leads are attached to the epicardial surface; usually used in the diagnosis and treatment of postoperative dysrhythmias.
escape pacemaker an ectopic pacemaker that assumes control of cardiac impulse propagation because of failure of the sinoatrial node to generate one or more normal impulses.
external pacemaker an artificial pacemaker located outside the body; the primary types are transcutaneous and transvenous. See also temporary pacemaker.
gastric pacemaker a saddle-shaped area of the greater curvature of the stomach at the junction of its proximal and middle thirds, which regulates the frequency of gastric contractions.
implantable pacemaker (implanted pacemaker) an artificial pacemaker implanted within the body.
phrenic pacemaker the device used in electrophrenic respiration; it converts radiofrequency signals into electrical impulses that stimulate the phrenic nerve, resulting in descent and flattening of the diaphragm and improved inhalation of air. Called also diaphragmatic pacemaker.
synchronous pacemaker an implanted pacemaker that synchronizes the physiological events in the atrium with those of the ventricle; it stimulates the ventricle when triggered by the P wave from the atrium.
temporary pacemaker an artificial pacemaker in which the pulse generator is not implanted, usually either a transcutaneous or transvenous pacemaker. See also external pacemaker.
transcutaneous pacemaker a temporary pacemaker in which large surface, high impedance electrodes are applied to the anterior and posterior chest walls to deliver high current stimuli of long duration for pacing of the ventricles.
transvenous pacemaker an artificial pacemaker, either external or implanted, that is connected to the heart by pacing leads passed through the venous circulation to make contact with the endocardium of the right atrium or right ventricle.
uterine pacemaker either of the two regulating centers that control uterine contractions, located near the openings of the fallopian tubes. When the fetus is ready to be born the pacemakers set off a series of rhythmic contractions in the uterine muscle that gradually force the infant out into the birth canal.
wandering pacemaker a condition in which the site of origin of the impulses controlling the heart rate shifts from the head of the sinoatrial node to a lower part of the node or to another part of the atrium.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

cardiac pacemaker

A device that delivers a small electric shock to the heart to effect cardiac contraction at a pre-determined rate
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.

car·di·ac pace·ma·ker

(kahr'dē-ak pas'māk-ĕr)
Surgically implanted electronic device to regulate the heartbeat.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012

cardiac pacemaker

Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005
References in periodicals archive ?
(11) reported five patients with PLSVC who underwent cardiac device implantation (three cardiac pacemakers, one CRT, and one VVI ICD).
This study aimed to evaluate the safety and efficacy of the Qinming8631 DR implantable cardiac pacemaker. The commercially available Talos DR (Biotronik, Berlin, Germany) pacemaker was used as control, and noninferiority of the Qinming8631 DR to Talos DR pacemaker in Chinese patients was tested.
Effects of extracorporeal shock wave lithotripsy on cardiac pacemakers and its safety in patients with implanted cardiac pacemakers.
In addition to demographic data (age, gender), information was gathered on the cardiac pacemaker (type of device and reason for insertion), current cardiac medications, ECT (dose, electrode placement, and duration of electroencephalograph (EEG) and motor seizure), anaesthesia technique and complications.
If there is damage to the electrical route between the atrium and the lower chambers, it can result in complete 'heart block.' This is a potentially fatal condition that can only be treated a the moment by implanting a cardiac pacemaker.
Slide 7: Cardiac Pacemaker - Market overview, Market size and Growth (Volume-Wise: 2012 - 2018e), Market Size and Growth (Value-Wise: 2012 - 2018e)
Lyman and his colleagues found the exposure to 50 to 100 microamperes of electricity -- comparable to that produced by a cardiac pacemaker -- reduced the infectivity of the AIDS virus (HIV) by 50 to 95 percent.
This evidence is based on research findings from at least three sources: Wennberg's research demonstrating significant differences in health care utilization rates between small geographic areas, suggesting either overutilization in high use areas or underutilization in low use areaS4 ; the RAND studies of the appropriateness of utilization of six procedures in the Medicare population, demonstrating levels of unnecessary use of these procedures ranging from 14 to 32 percent'; and the research of Greenberg et al.1 demonstrating that approximately 20 percent of cardiac pacemaker implants performed in the study were done for inappropriate reasons.
Similar in function and appearance to a cardiac pacemaker, the Protege neurostimulator delivers mild electrical pulses to the spinal cord, which interrupt or mask the pain signals' transmission to the brain.
9 ( ANI ): This February, and Indian-origin doctor implanted the United States' first miniature-sized, leadless cardiac pacemaker directly inside a patient's heart without surgery.
Head of neurosurgery Ciaran Bolger said the device was "like a cardiac pacemaker".