title: Clinical impact of the number of extrastimuli in programmed electrical stimulation in patients with Brugada type 1 electrocardiogram.
abstract: BACKGROUND
  Use of programmed electrical stimulation (PES) for risk stratification of Brugada syndrome (BrS) is controversial.
  
  
  OBJECTIVE
  To elucidate the role of the number of extrastimuli during PES in patients with BrS.
  
  
  METHODS
  Consecutive 108 patients with type 1 electrocardiogram (104 men, mean age 46 ± 12 years; 26 with ventricular fibrillation [VF], 40 with syncope, and 42 asymptomatic) underwent PES with a maximum of 3 extrastimuli from the right ventricular apex and the right ventricular outflow tract. Ventricular arrhythmia (VA) was defined as VF or nonsustained polymorphic ventricular tachycardia >15 beats. Patients with VA induced by a single extrastimulus or double extrastimuli were assigned to group SD (Single/Double), by triple extrastimuli to group T (Triple), and the remaining patients to group N.
  
  
  RESULTS
  VA was induced in 81 patients (VF in 71 and polymorphic ventricular tachycardia in 10), in 4 by a single extrastimulus, in 41 by double extrastimuli, and in 36 by triple extrastimuli. During 79 ± 48 months of follow-up, 24 patients had VF events. Although the overall inducibility of VA was not associated with an increased risk of VF (log-rank P = .78), group SD had worse prognosis than did group T (P = .004). Kaplan-Meier analysis in patients without prior VF also showed that group SD had poorer outcome than did group T and group N (P = .001). Positive and negative predictive values of VA induction with up to 2 extrastimuli were, respectively, 36% and 87%, better than those with up to 3 (23% and 81%, respectively).
  
  
  CONCLUSIONS
  The number of extrastimuli that induced VA served as a prognostic indicator for patients with Brugada type 1 electrocardiogram. Single extrastimulus or double extrastimuli were adequate for PES of patients with BrS.
authors.affiliation: Division of Arrhythmia and Electrophysiology, Department of Cardiovascular Medicine, National Cerebral and Cardiovascular Center, Suita, Osaka, Japan.
authors.forename: Hisaki
authors.initials: H
authors.lastname: Makimoto
authors.forename: Shiro
authors.initials: S
authors.lastname: Kamakura
authors.forename: Naohiko
authors.initials: N
authors.lastname: Aihara
authors.forename: Takashi
authors.initials: T
authors.lastname: Noda
authors.forename: Ikutaro
authors.initials: I
authors.lastname: Nakajima
authors.forename: Teruki
authors.initials: T
authors.lastname: Yokoyama
authors.forename: Atsushi
authors.initials: A
authors.lastname: Doi
authors.forename: Hiro
authors.initials: H
authors.lastname: Kawata
authors.forename: Yuko
authors.initials: Y
authors.lastname: Yamada
authors.forename: Hideo
authors.initials: H
authors.lastname: Okamura
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Satomi
authors.forename: Takeshi
authors.initials: T
authors.lastname: Aiba
authors.forename: Wataru
authors.initials: W
authors.lastname: Shimizu
mesh_terms: D000328:Adult; D053840:Brugada Syndrome / Q000150:complications / Q000503:physiopathology*; D004562:Electrocardiography; D022062:Electrophysiologic Techniques, Cardiac / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006352:Heart Ventricles / Q000503:physiopathology*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D018570:Risk Assessment; D017180:Tachycardia, Ventricular / Q000209:etiology / Q000503:physiopathology*; D014693:Ventricular Fibrillation / Q000209:etiology / Q000503:physiopathology*