title: Comparison of conduction delay in the right ventricular outflow tract between Brugada syndrome and right ventricular cardiomyopathy: investigation of signal average ECG in the precordial leads.
abstract: BACKGROUND
  In both Brugada syndrome (BS) and arrhythmogenic right ventricular cardiomyopathy (ARVC), electrical abnormalities in the right ventricular outflow tract (RVOT) are important for arrhythmogenesis.
  
  
  OBJECTIVE
  The aim of this study was to compare conduction delay in the right ventricular in BS with that in ARVC using the signal-averaged electrocardiogram.
  
  
  METHODS
  Twenty patients with BS (18 men and 2 women; 55 +/- 12 years old; 9 symptomatic and 11 asymptomatic) and eight patients with ARVC (six men and two women; 53 +/- 16 years old) were included. We assessed the presence of late potentials (LPs) and the filtered QRS duration (fQRSd) in V(2) and V(5) using a high-pass filter of 40 Hz (fQRSd:40) and 100 Hz (fQRSd:100).
  
  
  RESULTS
  In ARVC, there was no significant difference in fQRSd:40 between V2 and V5 (158 +/- 19 vs. 145 +/- 17 ms, respectively): however, in BS, fQRSd:40 in V2 was significantly longer than fQRSd:40 in V5 (147 +/- 15 vs. 125 +/- 10 ms, P < 0.001). In ARVC, there was no significant difference between fQRSd:40 and fQRSd:100 in V(2) and V(5) (158 +/- 19 vs. 142 +/- 23 ms and 145 +/- 17 vs. 132 +/- 9 ms, respectively). In contrast, in BS, fQRSd:100 was significantly shorter than fQRSd:40 in V2 (110 +/- 8 ms vs. 147 +/- 15, P < 0.001). The relative decrease in fQRSd:100 compared with fQRSd:40 in V2 was significantly greater in BS than in ARVC.
  
  
  CONCLUSIONS
  The dominant prolongation of the fQRSd in the right precordial lead in BS was different from the characteristics of ARVC, which may be caused by the conduction delay due to fibro-fatty replacement in RV.
authors.affiliation: The First Department of Internal Medicine, Niigata University School of Medicine, 1-754 Asahi-machi-dori, Niigata, 951-8510, Japan. chimiri@med.niigata-u.ac-jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Furushima
authors.forename: Masaomi
authors.initials: M
authors.lastname: Chinushi
authors.forename: Kazuki
authors.initials: K
authors.lastname: Okamura
authors.forename: Kenichi
authors.initials: K
authors.lastname: Iijima
authors.forename: Satoru
authors.initials: S
authors.lastname: Komura
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Tanabe
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Okada
authors.forename: Daisuke
authors.initials: D
authors.lastname: Izumi
authors.forename: Yoshifusa
authors.initials: Y
authors.lastname: Aizawa
mesh_terms: D000328:Adult; D000368:Aged; D019571:Arrhythmogenic Right Ventricular Dysplasia / Q000175:diagnosis*; D053840:Brugada Syndrome / Q000175:diagnosis*; D002320:Cardiovascular Physiological Phenomena; D004562:Electrocardiography / Q000379:methods*; D022062:Electrophysiologic Techniques, Cardiac / Q000379:methods*; D005260:Female; D006352:Heart Ventricles / Q000473:pathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D012815:Signal Processing, Computer-Assisted; D018497:Ventricular Dysfunction, Right / Q000175:diagnosis; D014693:Ventricular Fibrillation