title: Epicardial electrogram of the right ventricular outflow tract in patients with the Brugada syndrome: using the epicardial lead.
abstract: OBJECTIVE
  We tried to record an epicardial electrogram directly, and we examined local electrograms before and after administration of a class IC anti-arrhythmic drug in patients with the Brugada syndrome.
  
  
  BACKGROUND
  Electrical heterogeneity of the epicardium in the right ventricular outflow tract (RVOT) has been thought to be related to the Brugada syndrome. However, an epicardial abnormality has not been demonstrated in patients with the Brugada syndrome.
  
  
  METHODS
  In five patients with a Brugada-type electrocardiogram (ECG), local unipolar electrograms were recorded at the epicardium and endocardium of the RVOT. To record the epicardial electrogram directly, we introduced an electrical guidewire into the conus branch (CB) of the right coronary artery. The duration of the local electrogram after termination of the QRS complex (DP) was measured before and after class IC anti-arrhythmic drug administration. The signal-averaged electrocardiogram (SAECG) was also obtained in all patients.
  
  
  RESULTS
  A definite DP was observed at the epicardium, but not at the endocardium. After administration of a class IC anti-arrhythmic drug, the DP at the epicardium was prolonged from 38 +/- 10 ms to 67 +/- 24 ms. The late potential corresponding to the DP at the epicardium was observed in all patients on the SAECG.
  
  
  CONCLUSIONS
  An epicardial electrogram can be recorded from the CB. Recording from the CB enables identification of an epicardial abnormality in patients with the Brugada syndrome. These abnormal electrograms may be related to a myocardial abnormality in the epicardium of patients with the Brugada syndrome.
authors.affiliation: Department of Cardiovascular Medicine, Okayama University Graduate School of Medicine and Dentistry, Okayama, Japan. snagse@cc.okayama-u.ac.jp
authors.forename: Satoshi
authors.initials: S
authors.lastname: Nagase
authors.forename: Kengo Fukushima
authors.initials: KF
authors.lastname: Kusano
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Morita
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Fujimoto
authors.forename: Mikio
authors.initials: M
authors.lastname: Kakishita
authors.forename: Kazufumi
authors.initials: K
authors.lastname: Nakamura
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Emori
authors.forename: Hiromi
authors.initials: H
authors.lastname: Matsubara
authors.forename: Tohru
authors.initials: T
authors.lastname: Ohe
mesh_terms: D000200:Action Potentials; D000328:Adult; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology; D004562:Electrocardiography; D006329:Heart Conduction System / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D012815:Signal Processing, Computer-Assisted; D013577:Syndrome; D014693:Ventricular Fibrillation / Q000175:diagnosis*
chemical_list: D000889:Anti-Arrhythmia Agents