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the ability of a cell to depolarize itself, reach threshold potential, and produce a propagated action potential; cells with this capability are called automatic cells.
abnormal automaticity a type of altered automaticity occurring in cells that do not normally possess that property, as in myocardial cells with severely depressed function that have lost their fast sodium channels.
altered automaticity ectopic automatic firing of myocardial cells; there are two types, enhanced normal automaticity and abnormal automaticity.
enhanced normal automaticity a type of altered automaticity seen in pacemaker cells, caused by a steepening of phase 4 such as occurs in the presence of excess catecholamines, which causes premature beats to occur.
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 pacing The inherent property of individual myocardial cells to depolarize spontaneously Neurology Automatism, see there.
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.


A property of myocardial cells by which they intrinsically depolarize and initiate an action potential.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012

Patient discussion about automaticity

Q. My friend told me that following a vegetarian diet will help to lose weight automatically? Is that so? My friend told me that following a vegetarian diet will help to lose weight automatically? Is that so?

A. No necessarily. Your body will be in shock for a bit from the switch over. I think eating natural and unprocessed foods cause the major decline in weight since its all natural.

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References in periodicals archive ?
It is believed to originate from a focus with abnormal automaticity within or immediately adjacent to the atrioventricular junction and is believed to be secondary to trauma, infiltrative hemorrhage, or inflammation of the conduction tissue.[1] The nature of congenital heart surgery and its repair have been implicated as a major contributor to the genesis of junctional ectopic tachycardia.[2] Postoperative junctional ectopic tachycardia is associated with manipulation within the crux of the heart, resulting in myocardial injury which increases the electrical excitability in heart tissue.
Atrial tachycardia may be reentrant or may be caused by abnormal automaticity or triggered activity.
Poorly perfused tissues or tissues exposed to electrolyte abnormalities cannot maintain normal cell membrane integrity and have a condition labeled abnormal automaticity. In states of abnormal automaticity, cells that normally have a slower rate of automaticity develop enhanced response rates.