title: Clinical electrophysiologic effects of flecainide acetate.
abstract: Flecainide acetate depresses the rate of depolarization of action potential (Vmax), the so-called "membrane stabilizing action." In the intact heart it has a unique profile of substantial effect on conduction with modest effect on refractoriness. After intravenous administration, clinical electrophysiologic studies show that conduction through atrial myocardium, atrioventricular (AV) node, His-Purkinje system, and ventricular myocardium is depressed, the most prominent effect being on the His-Purkinje system. Refractorines of the normal atrial and AV nodal myocardium is not prolonged while that of the ventricular muscle is slightly increased. Atrial fibrillation (60% to 70%), atrial tachycardia (90% to 100%), and nodal and AV tachycardia (80% to 90%) are generally terminated, while flutter is usually slowed, but in a small proportion of patients (10% to 20%) might be terminated by the intravenous use of flecainide acetate. This drug has also been shown to be effective in terminating stable ventricular tachycardia (70%). However, it appears to be slightly less effective in suppressing inducibility of ventricular arrhythmias. Administered orally, flecainide is very effective in decreasing ventricular ectopic activity (80% to 95%) and nonsustained ventricular tachycardia. Thus, flecainide has a wide range of antiarrhythmic properties, making it a useful agent in the management of a variety of supraventricular and ventricular arrhythmias. In a small proportion of patients, however, its use can lead to apparent arrhythmogenic effects, the most dangerous being exacerbation of ventricular tachycardia.
authors.affiliation: Department of Cardiological Sciences, St. George's Hospital Medical School, London, England.
authors.forename: D
authors.initials: D
authors.lastname: Mehta
authors.forename: A J
authors.initials: AJ
authors.lastname: Camm
authors.forename: D E
authors.initials: DE
authors.lastname: Ward
mesh_terms: D000818:Animals; D004594:Electrophysiology; D005424:Flecainide / Q000494:pharmacology*; D006321:Heart / Q000187:drug effects* / Q000502:physiology; D006801:Humans
chemical_list: D005424:Flecainide