Enhanced Depolarization Drive in Failing Rabbit Ventricular Myocytes: Calcium-Dependent and β-Adrenergic Effects on Late Sodium, L-Type Calcium, and Sodium-Calcium Exchange Currents.

ABSTRACT:

Background

Heart failure (HF) is characterized by electrophysiological remodeling resulting in increased risk of cardiac arrhythmias. Previous reports suggest that elevated inward ionic currents in HF promote action potential (AP) prolongation, increased short-term variability of AP repolarization, and delayed afterdepolarizations. However, the underlying changes in late Na⁺ current (I_NaL), L-type Ca²⁺ current, and NCX (Na⁺/Ca²⁺ exchanger) current are often measured in nonphysiological conditions (square-pulse voltage clamp, slow pacing rates, exogenous Ca²⁺ buffers).

Methods

We measured the major inward currents and their Ca²⁺- and β-adrenergic dependence under physiological AP clamp in rabbit vent

SUBMITTER: Hegyi B 

PROVIDER: S-EPMC6720130 | biostudies-literature | 2019 Mar

REPOSITORIES: biostudies-literature