title: Ajmaline attenuates electrocardiogram characteristics of inferolateral early repolarization.
abstract: BACKGROUND
  J waves are the hallmark of both inferolateral early repolarization (ER) and Brugada syndrome. While ajmaline, a class 1a antiarrhythmic drug, accentuates the J wave in Brugada syndrome, its effect on ER is unreported.
  
  
  OBJECTIVE
  To describe the effect of ajmaline on the electrocardiogram in ER.
  
  
  METHODS
  We analyzed electrocardiograms before and after the administration of intravenous ajmaline (1 mg/kg) in 31 patients with ER, 21 patients with Brugada type 1 electrocardiogram (Br), and 22 controls. ER was defined as J-point elevation of ≥1 mm with QRS slurring or notching in ≥2 inferolateral leads (I, aVL, II, III, aVF, V4-V6).
  
  
  RESULTS
  Ajmaline decreased mean J-wave amplitude in the ER group from 0.2 ± 0.15 mV at baseline to 0.08 ± 0.09 mV (P < .001). The QRS width prolonged significantly in all 3 groups, but the prolongation was significantly less in the ER group (+21 ms) than in the Br group (+36 ms; P < .001) or controls (+28 ms; P = .010). Decrease in mean inferolateral R-wave amplitude was similar in all the groups (ER group -0.14 mV; Br group -0.11 mV; controls -0.13 mV; P = ns), but mean inferolateral S-wave amplitude increased significantly less in the ER group (ER group +0.14 mV; Br group +16 mV; controls +0.20 mV; P < .001).
  
  
  CONCLUSIONS
  Ajmaline significantly decreases the J-wave amplitude in ER and prolongs the QRS width significantly less than in patients with Br. This indicates a different pathogenesis for both disorders. The altered terminal QRS vector probably is responsible for the decrease in the J-wave amplitude in ER, although a specific effect of ajmaline on J waves cannot be excluded.
authors.affiliation: Hôpital Cardiologique du Haut-Lévêque, Bordeaux, France. laurent.roten@insel.ch
authors.forename: Laurent
authors.initials: L
authors.lastname: Roten
authors.forename: Nicolas
authors.initials: N
authors.lastname: Derval
authors.forename: Frédéric
authors.initials: F
authors.lastname: Sacher
authors.forename: Patrizio
authors.initials: P
authors.lastname: Pascale
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Wilton
authors.forename: Daniel
authors.initials: D
authors.lastname: Scherr
authors.forename: Ashok
authors.initials: A
authors.lastname: Shah
authors.forename: Michala E F
authors.initials: ME
authors.lastname: Pedersen
authors.forename: Amir S
authors.initials: AS
authors.lastname: Jadidi
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Miyazaki
authors.forename: Sébastien
authors.initials: S
authors.lastname: Knecht
authors.forename: Mélèze
authors.initials: M
authors.lastname: Hocini
authors.forename: Pierre
authors.initials: P
authors.lastname: Jaïs
authors.forename: Michel
authors.initials: M
authors.lastname: Haïssaguerre
mesh_terms: D000328:Adult; D000404:Ajmaline / Q000494:pharmacology* / Q000627:therapeutic use; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology* / Q000627:therapeutic use; D053840:Brugada Syndrome / Q000188:drug therapy* / Q000503:physiopathology; D016022:Case-Control Studies; D004562:Electrocardiography / Q000187:drug effects*; D005260:Female; D006329:Heart Conduction System / Q000187:drug effects*; D006801:Humans; D008297:Male
chemical_list: D000889:Anti-Arrhythmia Agents; D000404:Ajmaline