title: Effect of a single oral dose of pilsicainide on pacing thresholds in pacemaker patients with and without paroxysmal atrial fibrillation.
abstract: A single oral dose of pilsicainide, a class 1c antiarrhythmic drug, is effective in terminating acute-onset atrial fibrillation (AF), but its effect on pacing thresholds in pacemaker patients is unknown. The present study measured atrial and ventricular pacing thresholds after a single oral dose of pilsicainide in patients with and without AF. Twelve patients with dual-chamber pacemakers were evaluated. Pacing thresholds as well as plasma pilsicainide concentration were measured prior to and then at 30, 60, 90, 120 and 180 min and 24h following a single oral dose of pilsicainide (150 mg). Six patients had paroxysmal AF and the remaining 6 did not. Pacing thresholds increased significantly (134+/-8%) in the atrium (p<0.05) and in the ventricle (155+/-11%; p<0.001) following pilsicainide administration in all 12 patients. Plasma concentrations of pilsicainide showed a positive liner correlation with pacing thresholds (R=0.62, p<0.0001 in the atrium; R=0.74, p<0.0001 in the ventricle). Atrial pacing thresholds in the patients with AF showed a significant increase at 90, 120 and 180 min compared with the patients without AF (p<0.05). There was no significant difference in either the ventricular pacing threshold or the plasma pilsicainide concentration in the patients with and without AF. It was concluded that a single oral dose of pilsicainide increases the pacing thresholds in both the atrium and ventricle in a selected group of pacemaker-implanted patients; that is, those who are aged and with AF. Thus, careful attention should be paid to pacemaker-dependent patients, particularly those with paroxysmal AF, when administering pilsicainide.
authors.affiliation: Second Department of Internal Medicine, University of Occupational and Environmental Health, Kitakyushu, Yahatanishi, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Numata
authors.forename: H
authors.initials: H
authors.lastname: Abe
authors.forename: T
authors.initials: T
authors.lastname: Nagatomo
authors.forename: K
authors.initials: K
authors.lastname: Kohshi
authors.forename: Y
authors.initials: Y
authors.lastname: Nakashima
mesh_terms: D000284:Administration, Oral; D000368:Aged; D000889:Anti-Arrhythmia Agents / Q000008:administration & dosage* / Q000097:blood; D001145:Arrhythmias, Cardiac / Q000628:therapy; D001281:Atrial Fibrillation / Q000150:complications*; D002304:Cardiac Pacing, Artificial; D004341:Drug Evaluation; D005260:Female; D006801:Humans; D008012:Lidocaine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood; D008297:Male; D010138:Pacemaker, Artificial
chemical_list: D000889:Anti-Arrhythmia Agents; D008012:Lidocaine; C042288:pilsicainide