title: Epsilon-like waves and ventricular conduction abnormalities in subjects with type 1 ECG pattern of Brugada syndrome.
abstract: BACKGROUND
  Previous studies have demonstrated an overlap between the arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) and Brugada syndrome (BS). Conduction delay in the right ventricle has been demonstrated in both entities.
  
  
  OBJECTIVE
  This study investigated specific ARVC/D electrocardiographic (ECG) markers in subjects with spontaneous or drug-induced type 1 ECG pattern of BS.
  
  
  METHODS
  The study population consisted of 47 apparently healthy individuals (38 men, mean age 44.1 ± 13.3 years) with spontaneous (n = 17) or drug-induced (n = 30) type 1 ECG phenotype of BS. The clinical records of these individuals were retrospectively analyzed.
  
  
  RESULTS
  Fifteen subjects (31.9%) were symptomatic, with a history of syncope. A family history of BS or sudden cardiac death was reported in 10 (21.3%) and 8 (17.0%) cases, respectively. Epsilon-like waves in leads V1-V3 were observed in 6 subjects (12.7%). Epsilon-like waves were seen in spontaneous type 1 ECGs in 2 cases and after sodium channel blocking test in 4 cases. In baseline ECGs, localized prolongation (>110 ms) of the QRS complex in leads V1-V3, QRS duration ratio in (V1+V2+V3)/(V4+V5+V6) ≥ 1.2, and prolonged S wave upstroke (>55 ms) in leads V1-V3 were seen in 48.8%, 29.8%, and 40.4% of subjects, respectively. Epsilon-like waves and delayed S wave upstroke were more commonly observed in subjects with family history of BS (P = .014 and P = .038, respectively).
  
  
  CONCLUSIONS
  Specific ECG markers that reflect ventricular conduction delay in ARVC/D are commonly observed in subjects with spontaneous or drug-induced type 1 ECG pattern of BS as well. These depolarization abnormalities may be related to subtle underlying structural abnormalities.
authors.affiliation: Second Department of Cardiology, Evangelismos General Hospital of Athens, Greece. k.letsas@mail.gr
authors.forename: Konstantinos P
authors.initials: KP
authors.lastname: Letsas
authors.forename: Michael
authors.initials: M
authors.lastname: Efremidis
authors.forename: Reinhold
authors.initials: R
authors.lastname: Weber
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Korantzopoulos
authors.forename: Nikos
authors.initials: N
authors.lastname: Protonotarios
authors.forename: Efstathia
authors.initials: E
authors.lastname: Prappa
authors.forename: Stavros P
authors.initials: SP
authors.lastname: Kounas
authors.forename: Eleni N
authors.initials: EN
authors.lastname: Evagelidou
authors.forename: Sotirios
authors.initials: S
authors.lastname: Xydonas
authors.forename: Dietrich
authors.initials: D
authors.lastname: Kalusche
authors.forename: Antonios
authors.initials: A
authors.lastname: Sideris
authors.forename: Thomas
authors.initials: T
authors.lastname: Arentz
mesh_terms: D000328:Adult; D053840:Brugada Syndrome / Q000139:chemically induced / Q000175:diagnosis / Q000503:physiopathology*; D004562:Electrocardiography / Q000187:drug effects*; D005260:Female; D005500:Follow-Up Studies; D006329:Heart Conduction System / Q000187:drug effects / Q000503:physiopathology*; D006352:Heart Ventricles / Q000187:drug effects / Q000294:innervation* / Q000503:physiopathology; D006801:Humans; D008297:Male; D012189:Retrospective Studies; D026941:Sodium Channel Blockers / Q000009:adverse effects*; D016278:Ventricular Function, Right / Q000187:drug effects / Q000502:physiology*
chemical_list: D026941:Sodium Channel Blockers