title: Differences in 12-lead electrocardiogram between symptomatic and asymptomatic Brugada syndrome patients.
abstract: BACKGROUND
  Brugada syndrome (BrS) is an inherited disorder that predisposes some subjects to sudden cardiac death (SCD). It is not well established which BrS patients are at risk of severe arrhythmias. Our aim was to study whether standard 12-lead electrocardiogram (ECG) would give useful information for this purpose.
  
  
  METHODS
  This study included 200 BrS probands (142 male, 62%; mean age 42 +/- 16 years). Symptoms related to BrS were defined as syncope, documented ventricular tachyarrhythmia, or SCD. We determined PR, QRS, QTc, T(peak), and T(end) interval from leads II and V(2) and QRS from lead V(5), R'/S ratio from lead aVR (aVR sign), QRS axis, and J-point elevation amplitude from right precordial leads from the baseline ECGs.
  
  
  RESULTS
  Sixty-six subjects (33%) had experienced symptoms related to BrS. The only significant difference between the symptomatic and asymptomatic BrS subjects was the QRS duration measured from lead II or lead V(2), for example, the mean QRS in V(2) was 115 +/- 26 ms in symptomatic versus 104 +/- 19 ms in asymptomatic patients (P < 0.001). The optimized cut-off point of V(2) QRS > or =120 ms gave an odds ratio (OR) of 2.5 (95% CI: 1.4-4.6, P = 0.003) for being symptomatic. In a multivariate analysis adjusted with gender, age, and SCN5A mutation, the OR was 2.6 (95% CI: 1.4-4.8, P = 0.004).
  
  
  CONCLUSIONS
  Prolonged QRS duration, measured from standard 12-lead ECG, is associated with symptoms and could serve as a simple noninvasive risk marker of vulnerability to life-threatening ventricular arrhythmias in BrS.
authors: Division of Cardiology, Department of Medicine, University of Oulu, Finland. mattiju@mail.student.oulu.fi
authors: M Juhani
authors: MJ
authors: Junttila
authors: Pedro
authors: P
authors: Brugada
authors: Kui
authors: K
authors: Hong
authors: Eric
authors: E
authors: Lizotte
authors: Marc
authors: M
authors: DE Zutter
authors: Andrea
authors: A
authors: Sarkozy
authors: Josep
authors: J
authors: Brugada
authors: Begona
authors: B
authors: Benito
authors: Juha S
authors: JS
authors: Perkiomaki
authors: Timo H
authors: TH
authors: Mäkikallio
authors: Heikki V
authors: HV
authors: Huikuri
authors: Ramon
authors: R
authors: Brugada
mesh_terms: D000328:Adult; D053840:Brugada Syndrome / Q000145:classification* / Q000175:diagnosis*; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity