title: Differentiation of the electrophysiological effects on the atrial myocardium between the pure Na channel blocker, pilsicainide, and flecainide.
abstract: The purpose of this study was to identify the difference between the pure Na channel blocker, pilsicainide and Ic-antiarrhythmic drug, flecainide, on the atrial electrophysiological characteristics.
  
  
  METHODS
  The subjects consisted of 24 patients (48 +/- 12 years-old: P-group) in whom pilsicainide was administrated intravenously (1 mg/kg/10 min) and 31 patients (47 +/- 15 years-old: F-group) in whom flecainide was administrated intravenously (2 mg/kg/10 min). The atrial effective refractory period (ERP-A), intra-atrial conduction time (CT), max intra-atrial conduction delay (Max CD), repetitive atrial firing zone (RAFZ), fragmented atrial activity zone (FAZ) and intra-atrial conduction delay zone (CDZ) were measured before and after the drugs.
  
  
  RESULTS
  Pilsicainide and flecainide significantly prolonged the ERP-A (211 +/- 27 msec to 246 +/- 39 msec; p < 0.001, 217 +/- 25 msec to 244 +/- 33 msec; p < 0.001, respectively) and CT (121 +/- 33 msec to 149 +/- 43 msec; p < 0.001, 122 +/- 22 msec to 153 +/- 27 msec; p < 0.001, respectively) to the same degree. However, the Max CD was shortened by pilsicainide, but not by flecainide. The RAFZ, FAZ and CDZ decreased in the P-group (21 +/- 25 msec to 4 +/- 10 msec; p < 0.01, 24 +/- 24 msec to 14 +/- 18 msec; p < 0.05, 56 +/- 29 msec to 43 +/- 32 msec, p < 0.05, respectively), but not in the F-group.
  
  
  CONCLUSIONS
  The effects of atrial conduction delays may differ between pilsicainide and flecainide. Further examination will be needed to explain this mechanism.
authors.affiliation: Division of Cardiovascular Medicine, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-kogushi, Ube, Yamaguchi 755-8505, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Kanemoto
authors.forename: Akihiko
authors.initials: A
authors.lastname: Shimizu
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Yamagata
authors.forename: Masahiro
authors.initials: M
authors.lastname: Esato
authors.forename: Takeshi
authors.initials: T
authors.lastname: Ueyama
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Yoshiga
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Kakugawa
authors.forename: Ryousuke
authors.initials: R
authors.lastname: Kametani
authors.forename: Noriko
authors.initials: N
authors.lastname: Inoue
authors.forename: Akira
authors.initials: A
authors.lastname: Sawa
authors.forename: Masunori
authors.initials: M
authors.lastname: Matsuzaki
mesh_terms: D000328:Adult; D000889:Anti-Arrhythmia Agents / Q000097:blood / Q000627:therapeutic use*; D001282:Atrial Flutter / Q000188:drug therapy; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D005424:Flecainide / Q000097:blood / Q000627:therapeutic use*; D006325:Heart Atria / Q000187:drug effects* / Q000503:physiopathology; D006329:Heart Conduction System / Q000187:drug effects; D006352:Heart Ventricles / Q000187:drug effects; D006801:Humans; D008012:Lidocaine / Q000031:analogs & derivatives* / Q000097:blood / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009206:Myocardium; D011446:Prospective Studies; D012032:Refractory Period, Electrophysiological / Q000187:drug effects; D012107:Research Design; D026941:Sodium Channel Blockers / Q000097:blood / Q000627:therapeutic use*; D013611:Tachycardia, Atrioventricular Nodal Reentry / Q000188:drug therapy; D017180:Tachycardia, Ventricular / Q000188:drug therapy; D016896:Treatment Outcome; D014927:Wolff-Parkinson-White Syndrome / Q000188:drug therapy
chemical_list: D000889:Anti-Arrhythmia Agents; D026941:Sodium Channel Blockers; D008012:Lidocaine; C042288:pilsicainide; D005424:Flecainide