title: Frequency-dependent electrophysiological effects of flecainide, nifekalant and d,l-sotalol on the human atrium.
abstract: To compare the effects of class Ic and III antiarrhythmic agents on the termination and prevention of atrial fibrillation, the present study investigated the use-dependent electrophysiological effects of flecainide, nifekalant and d,l-sotalol on the human atrium. Flecainide significantly prolonged effective refractory period (ERP), intra-atrial conduction time (IACT) and monophasic action potential duration (MAPD), and its effects on ERP and IACT were use-dependent. Nifekalalant significantly prolonged ERP and MAPD, and these effects were reverse use-dependent; however, there was no significant change in IACT. d,l-Sotalol significantly prolonged MAPD and the effect was reverse use-dependent. It significantly prolonged ERP, but the effect was not reverse use-dependent. d,l-Sotalol increased IACT in a use-dependent manner. Thus, for atrial fibrillation, class Ic antiarrhythmic agents might be more effective in termination and class III antiarrhythmic agents might be more effective in prevention.
authors.affiliation: The Second Department of Medicine, Nihon University School of Medicine, Tokyo, Japan. iwatanab@med.nihon-u.ac.jp
authors.forename: H
authors.initials: H
authors.lastname: Watanabe
authors.forename: I
authors.initials: I
authors.lastname: Watanabe
authors.forename: T
authors.initials: T
authors.lastname: Nakai
authors.forename: N
authors.initials: N
authors.lastname: Oshikawa
authors.forename: S
authors.initials: S
authors.lastname: Kunimoto
authors.forename: R
authors.initials: R
authors.lastname: Masaki
authors.forename: T
authors.initials: T
authors.lastname: Kojima
authors.forename: S
authors.initials: S
authors.lastname: Saito
authors.forename: Y
authors.initials: Y
authors.lastname: Ozawa
authors.forename: K
authors.initials: K
authors.lastname: Kanmatuse
mesh_terms: D000200:Action Potentials / Q000187:drug effects; D000293:Adolescent; D000328:Adult; D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology*; D001281:Atrial Fibrillation / Q000188:drug therapy / Q000517:prevention & control; D016275:Atrial Function; D015331:Cohort Studies; D004341:Drug Evaluation; D022062:Electrophysiologic Techniques, Cardiac; D005424:Flecainide / Q000494:pharmacology*; D006325:Heart Atria / Q000187:drug effects*; D006801:Humans; D008875:Middle Aged; D011744:Pyrimidinones / Q000494:pharmacology*; D013015:Sotalol / Q000494:pharmacology*
chemical_list: D000889:Anti-Arrhythmia Agents; D011744:Pyrimidinones; C076259:nifekalant; D013015:Sotalol; D005424:Flecainide