Electrophysiological actions of flecainide in normal and infarcted canine Purkinje fibers

Eur J Pharmacol. 1985 May 28;112(1):57-64. doi: 10.1016/0014-2999(85)90238-9.

Abstract

The electrophysiological effects of flecainide, 0.1, 0.5 and 1.0 mg/l, on action potential characteristics were examined in normal Purkinje fibers and Purkinje fibers surviving infarction, at stimulation cycle lengths of 1000 and 300 ms. Overshoot, amplitude and dV/dtmax were reduced significantly in a dose-dependent manner by flecainide in both normal Purkinje fibers and Purkinje fibers surviving infarction. Action potential duration was shortened by flecainide to a greater extent: at the cycle length of 1000 ms compared to 300 ms; at 50% repolarization compared to 90%; and in normal preparations compared to infarcted preparations. Activation time was increased by flecainide in a dose-dependent manner in both types of preparations. This effect was enhanced at the shorter cycle length. In both normal and infarcted preparations, flecainide shortened the ERP of those having a longer initial ERP and lengthened those with a shorter ERP. This effect was significant only at the stimulation cycle length of 1000 ms. This study indicates that flecainide has properties unique and different from traditional antiarrhythmic drugs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Action Potentials / drug effects
  • Animals
  • Dogs
  • Electrophysiology
  • Female
  • Flecainide
  • Heart Conduction System / drug effects*
  • In Vitro Techniques
  • Male
  • Microelectrodes
  • Myocardial Infarction / physiopathology*
  • Piperidines / pharmacology*
  • Purkinje Fibers / drug effects*

Substances

  • Piperidines
  • Flecainide