Atrium-selective sodium channel block as a strategy for suppression of atrial fibrillation: differences in sodium channel inactivation between atria and ventricles and the role of ranolazine.

ABSTRACT:

Background

The development of selective atrial antiarrhythmic agents is a current strategy for suppression of atrial fibrillation (AF).

Methods and results

Whole-cell patch clamp techniques were used to evaluate inactivation of peak sodium channel current (I(Na)) in myocytes isolated from canine atria and ventricles. The electrophysiological effects of therapeutic concentrations of ranolazine (1 to 10 micromol/L) and lidocaine (2.1 to 21 micromol/L) were evaluated in canine isolated coronary-perfused atrial and ventricular preparations. Half-inactivation voltage of I(Na) was approximately 15 mV more negative in atrial versus ventricular cells under control conditions; this difference increased after exposure to ranolazine. Ranolazine produced a marked use-dependent depressio

SUBMITTER: Burashnikov A 

PROVIDER: S-EPMC2566303 | biostudies-literature | 2007 Sep

REPOSITORIES: biostudies-literature