Atrial-ventricular differences in rabbit cardiac voltage-gated Na⁺ currents: Basis for atrial-selective block by ranolazine.

ABSTRACT:

Background

Class 1 antiarrhythmic drugs are highly effective in restoring and maintaining sinus rhythm in atrial fibrillation patients but carry a risk of ventricular tachyarrhythmia. The antianginal agent ranolazine is a prototypic atrial-selective voltage-gated Na⁺ channel blocker but the mechanisms underlying its atrial-selective action remain unclear.

Objective

The present study examined the mechanisms underlying the atrial-selective action of ranolazine.

Methods

Whole-cell voltage-gated Na⁺ currents (I_Na) were recorded at room temperature (∼22°C) from rabbit isolated left atrial and right ventricular myocytes.

Results

I_Na conductance density was ∼1.8-fold greater in atrial than in ventricular cells. Atrial I

SUBMITTER: Caves RE 

PROVIDER: S-EPMC5666337 | biostudies-literature | 2017 Nov

REPOSITORIES: biostudies-literature