afterdepolarization


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afterdepolarization

 [af″ter-de-po″lah-rĭ-za´shun]
an oscillation in membrane potential that is dependent upon a preceding action potential for its initiation, and which upon reaching threshold potential can induce arrhythmias that are said to be “triggered.” Early afterdepolarizations occur during phases 2 and 3 of repolarization; delayed afterdepolarizations follow full repolarization.

afterdepolarization

/af·ter·de·po·lar·iza·tion/ (af″ter-de-po″lar-ĭ-za´shun) a depolarizing afterpotential, frequently one of a series, sometimes occurring in tissues not normally excitable. It may occur before (early a.) or after (delayed a.) full repolarization.

afterdepolarization

[-dēpō′lərizā′shən]
a membrane potential depolarization that follows an action potential. In cardiac muscles, it may be early (during phases 2 and 3 of the action potential) or delayed (during phase 4), and it is thought to cause atrial and ventricular tachycardia, especially in the setting of a long Q-T interval or digitalis poisoning. Also called afterpotential.

afterdepolarization

in myocardial activity a polarization, sufficient to trigger a cardiac cycle, which results from a preceding impulse or series of impulses.
References in periodicals archive ?
This increases the risk of early afterdepolarization, which, in turn, can cause polymorphic ventricular tachycardia.
In addition, the cardiomyocytes demonstrated signs of early afterdepolarization (about 66% of cells) and premature contractions (about 36% of cells).
Ks], resulting in delayed afterdepolarization (DADs) [18].
Qu, "Complex darly and delayed afterdepolarization dynamics caused by voltage-calcium coupling in cardiac myocytes," Biophysical Journal, vol.
sup][58],[60] Due to a marked difference in AP duration and the property of the delayed dome similar to early afterdepolarization, [sup][61] the dome may produce a new AP in the areas where complete loss of epicardial AP is present, leading to formation of short-coupled ectopic beats, which can be capable of originating polymorphic VT or VF.
Ventricular hypertrophy amplifies transmural repolarization dispersion and induces early afterdepolarization.
Ni ions have been reported to induce vasoconstriction and early afterdepolarization in isolated rat heart and canine coronary artery by enhancing [Ca.
Single and multiple early afterdepolarization caused by nickel in rat atrial muscle.
Delayed afterdepolarization reaching a critical threshold can trigger clinical arrhythmias, including ventricular extrasystoles, bidirectional ventricular tachycardia, and VF [17].
2+] currents, and maximum diastolic potential, leading to the development of early afterdepolarization (EAD) and arrhythmias.
currents, leading to the development of early afterdepolarizations (EADs) and slow response APs (4) observed in mXin[alpha]-/- myocytes.
It has been shown that ROS prolong action potential duration (APD) in rat and guinea pig myocytes and induce early afterdepolarizations (EADs) and delayed afterdepolarization (DADs) [27].