title: Risk stratification in patients with Brugada syndrome: analysis of daily fluctuations in 12-lead electrocardiogram (ECG) and signal-averaged electrocardiogram (SAECG).
abstract: BACKGROUND
  Risk stratification between symptomatic and asymptomatic patients with Brugada syndrome is not yet established. We compared daily fluctuations in 12-lead electrocardiogram (ECG) and signal-averaged ECG (SAECG) characteristics between symptomatic and asymptomatic patients with Brugada syndrome to identify new markers for distinguishing between high- and low-risk patients.
  
  
  RESULTS
  Thirty-five patients with Brugada syndrome underwent ECG and SAECG simultaneously at least 4 times every 3 months. We evaluated daily fluctuations (differences between maximum and minimum values) in ECG and SAECG characteristics and compared them between symptomatic (N = 11), and asymptomatic (N = 24) patients. On ECG, the daily fluctuations in r-J interval (interval from QRS onset to J point) in leads V1, V2, and V6 were significantly larger in symptomatic than in asymptomatic patients (V1; 20 +/- 6 vs 10 +/- 8 msec, P < 0.01, V2; 22 +/- 8 vs 11 +/- 4 msec, P < 0.01, and V6; 24 +/- 7 vs 14 +/- 7 msec, P < 0.01). On SAECG, daily fluctuations in filtered QRS (f-QRS) duration and LAS40 were significantly larger in symptomatic than in asymptomatic patients (f-QRS; 15 +/- 7 vs 9 +/- 4 msec, P < 0.05, and LAS40; 21 +/- 7 vs 10 +/- 6 msec, P < 0.05).
  
  
  CONCLUSIONS
  Instability of depolarization appears to be related to the risk of fatal ventricular arrhythmias in patients with Brugada syndrome. Daily fluctuations in ECG and SAECG characteristics could be useful for distinguishing between high- and low-risk patients with Brugada syndrome.
authors.affiliation: Department of Internal Medicine and Cardiology, Osaka City University Graduate School of Medicine, Osaka, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Tatsumi
authors.forename: Masahiko
authors.initials: M
authors.lastname: Takagi
authors.forename: Eiichiro
authors.initials: E
authors.lastname: Nakagawa
authors.forename: Hajime
authors.initials: H
authors.lastname: Yamashita
authors.forename: Minoru
authors.initials: M
authors.lastname: Yoshiyama
mesh_terms: D053840:Brugada Syndrome / Q000175:diagnosis* / Q000503:physiopathology*; D004562:Electrocardiography; D004566:Electrodes; D004867:Equipment Design; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018570:Risk Assessment