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Cl- current blockade reduces triggered activity based on delayed afterdepolarisations.

A O Verkerk, M W Veldkamp, A C G van Ginneken

    Netherlands Heart Journal : Monthly Journal of the Netherlands Society of Cardiology and the Netherlands Heart Foundation
    |February 20, 2015
    PubMed
    Summary

    The transient inward current (Iti) in sheep ventricular myocytes involves both chloride (Cl-) and sodium-calcium (Na+-Ca2+) exchange currents. Blocking the chloride current can reduce delayed after-depolarisations (DADs), potentially offering antiarrhythmic benefits.

    Keywords:
    afterdepolarisation

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    Area of Science:

    • Cardiovascular Physiology
    • Cardiac Electrophysiology
    • Ion Channel Function

    Background:

    • The transient inward current (Iti) is implicated in proarrhythmic delayed after-depolarisations (DADs).
    • A calcium-activated chloride current (ICl(Ca)) is increasingly recognized as a contributor to Iti.
    • The equilibrium potential for chloride ions (ECl) suggests ICl(Ca) can cause depolarizing currents at resting membrane potential.

    Conclusions:

    • Iti in sheep ventricular myocytes is mediated by both chloride and Na+-Ca2+ exchange currents.
    • Blockade of the chloride current component of Iti demonstrates potential antiarrhythmic effects by reducing DADs.
    • Targeting chloride currents may offer a novel therapeutic strategy for arrhythmias associated with DADs.