A TTX‐Sensitive Resting Na⁺ Permeability Contributes to the Catecholaminergic Automatic Activity in Rat Pulmonary Vein

Abstract

Na channels confer a TTX-sensitive basal Na(+) permeability to rat PV cardiac muscle cells and contribute to the slope of slow depolarization between bursts of CAA. Na channel blockers act mostly via reduction of the Na window current. Ranolazine also has an anti-α1 adrenergic effect, which contributed to its antiarrhythmic effect.