title: Variability of the diagnostic ECG pattern in an ICD patient population with Brugada syndrome.
abstract: BACKGROUND
  The spontaneous presence of a coved-type ECG is considered as an important risk factor in Brugada syndrome. However, diagnosis making and risk stratification may be hampered by the dynamic nature of the ECG abnormalities. The objective of this study was to determine the variability and predictive value of the electrocardiogram in Brugada patients implanted with a cardioverter-defibrillator (ICD).
  
  
  RESULTS
  We analyzed consecutive 12-lead ECGs from 89 ICD patients (44 +/- 14 years, 69 males) with Brugada syndrome. A total of 1,161 ECGs were included for analysis (13 +/- 8 ECGs/patient). Twenty-four percent of the ECGs/patient were coved-type I, 25% saddleback-type II or III, and 51% normal. Fifty-seven patients had a diagnostic coved-type ECG spontaneously (group A), 32 patients only after drug challenge (group B). In group A, 38% of the ECGs/patient were diagnostic, 25% saddleback-type, and 37% normal. Fifty-five group A patients (96%) had transient normalization and/or conversion to saddleback-type ECGs. During a mean follow-up of 48 +/- 35 months, 16 patients (18%) experienced appropriate shocks. All patients with appropriate shocks had spontaneous diagnostic ECGs. They tended to have more coved-type ECGs (36 vs 22%, respectively, P = 0.05) than patients without appropriate shocks.
  
  
  CONCLUSIONS
  Analysis of serial ECG recordings in an ICD patient population shows that the Brugada-ECG pattern is highly variable over time. In patients with spontaneous coved-type ECG, only every third ECG is diagnostic and every third ECG normal. Patients with spontaneous coved-type ST-segment elevation have a high incidence of appropriate shocks. Spontaneous saddleback-type electrocardiograms are not helpful for risk stratification.
authors.affiliation: Heart Rhythm Management Centre, Cardiovascular Centre, Free University of Brussels (UZ Brussel) VUB, Brussels, Belgium.
authors.forename: Sergio
authors.initials: S
authors.lastname: Richter
authors.forename: Andrea
authors.initials: A
authors.lastname: Sarkozy
authors.forename: Christian
authors.initials: C
authors.lastname: Veltmann
authors.forename: Gian-Battista
authors.initials: GB
authors.lastname: Chierchia
authors.forename: Tim
authors.initials: T
authors.lastname: Boussy
authors.forename: Christian
authors.initials: C
authors.lastname: Wolpert
authors.forename: Rainer
authors.initials: R
authors.lastname: Schimpf
authors.forename: Josep
authors.initials: J
authors.lastname: Brugada
authors.forename: Ramon
authors.initials: R
authors.lastname: Brugada
authors.forename: Martin
authors.initials: M
authors.lastname: Borggrefe
authors.forename: Pedro
authors.initials: P
authors.lastname: Brugada
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D053840:Brugada Syndrome / Q000175:diagnosis* / Q000517:prevention & control*; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D002648:Child; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D055815:Young Adult