title: Heterogeneous response of J-wave syndromes to beta-adrenergic stimulation.
abstract: BACKGROUND
  Inferolateral early repolarization (ER) and Brugada syndrome manifest with J waves. Isoproterenol suppresses recurrent ventricular arrhythmias while reducing J waves in both disorders.
  
  
  OBJECTIVE
  To characterize the effect of isoproterenol on J waves.
  
  
  METHODS
  We analyzed the impact of isoproterenol on J waves in 20 patients with Brugada-type electrocardiogram (Br group) and 38 patients with ER (ER group).
  
  
  RESULTS
  In the ER group, J waves were present in inferior leads in 32 patients (84%) and in lateral leads in 23 patients (61%). Isoproterenol increased the heart rate by 75 beats/min in the ER group and by 71 beats/min in the Br group (P = .20). The incidences of persistent (≤ 0.05-mV decrease), decreased, and normalized J waves (residual J wave ≤ 0.05 mV) were 20%, 80%, and 0% for Br group patients and 29%, 8%, and 63% for ER group patients, respectively (P <.001). Within the ER group, inferior J waves persisted in 34% of the cases, decreased in 9%, and normalized in 56% whereas lateral J waves always normalized (P <.001). Baseline QRS width was broader in ER group patients with persistent J waves (90 ms vs 80 ms; P = .003) and was unchanged with isoproterenol (90 ms; P = .19), whereas it decreased in the remaining patients (75 ms; P <.001).
  
  
  CONCLUSIONS
  J-wave syndromes have distinct regional sensitivity to beta-adrenergic stimulation. J waves may persist in a subset of patients with right precordial and inferior J waves but never in lateral location. This heterogeneous response to isoproterenol may indicate distinctive mechanisms for Brugada and ER patterns, including depolarization abnormalities or ion channel sensitivity.
authors.affiliation: Hôpital Cardiologique du Haut-Lévêque, Université Victor Segalen Bordeaux II, 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: Daniel
authors.initials: D
authors.lastname: Scherr
authors.forename: Yuki
authors.initials: Y
authors.lastname: Komatsu
authors.forename: Khaled
authors.initials: K
authors.lastname: Ramoul
authors.forename: Matthew
authors.initials: M
authors.lastname: Daly
authors.forename: Arnaud
authors.initials: A
authors.lastname: Denis
authors.forename: Ashok J
authors.initials: AJ
authors.lastname: Shah
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: D000318:Adrenergic beta-Agonists / Q000008:administration & dosage*; D000328:Adult; D053840:Brugada Syndrome / Q000188:drug therapy / Q000503:physiopathology*; D004562:Electrocardiography / Q000187:drug effects*; D005260:Female; D005500:Follow-Up Studies; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D007545:Isoproterenol / Q000008:administration & dosage*; D008297:Male; D016896:Treatment Outcome
chemical_list: D000318:Adrenergic beta-Agonists; D007545:Isoproterenol