title: Simultaneous Non-Invasive Epicardial and Endocardial Mapping in Patients With Brugada Syndrome: New Insights Into Arrhythmia Mechanisms.
abstract: The underlying mechanisms of Brugada syndrome (BrS) are not completely understood. Recent studies provided evidence that the electrophysiological substrate, leading to electrocardiogram abnormalities and/or ventricular arrhythmias, is located in the right ventricular outflow tract (RVOT). The purpose of this study was to examine abnormalities of epicardial and endocardial local unipolar electrograms by simultaneous noninvasive mapping in patients with BrS.
  
  
  
  Local epicardial and endocardial unipolar electrograms were analyzed using a novel noninvasive epi- and endocardial electrophysiology system (NEEES) in 12 patients with BrS and 6 with right bundle branch block for comparison. Fifteen normal subjects composed the control group. Observed depolarization abnormalities included fragmented electrograms in the anatomical area of RVOT endocardially and epicardially, significantly prolonged activation time in the RVOT endocardium (65±20 vs 38±13 ms in controls; P=0.008), prolongation of the activation-recovery interval in the RVOT epicardium (281±34 vs 247±26 ms in controls; P=0.002). Repolarization abnormalities included a larger area of ST-segment elevation >2 mV and T-wave inversions. Negative voltage gradient (-2.5 to -6.0 mV) between epicardium and endocardium of the RVOT was observed in 8 of 12 BrS patients, not present in patients with right bundle branch block or in controls.
  
  
  
  Abnormalities of epicardial and endocardial electrograms associated with depolarization and repolarization properties were found using NEEES exclusively in the RVOT of BrS patients. These findings support both, depolarization and repolarization abnormalities, being operative at the same time in patients with BrS.
authors.affiliation: Department of Medicine, University Medical Center Mannheim, Mannheim, Germany boris.rudic@gmail.com.|German Center for Cardiovascular Research (DZHK), Partner Site Heidelberg/Mannheim, Mannheim, Germany.
authors.forename: Boris
authors.initials: B
authors.lastname: Rudic
authors.affiliation: Petrovsky National Research Center of Surgery, Moscow, Russia.
authors.forename: Maria
authors.initials: M
authors.lastname: Chaykovskaya
authors.affiliation: Petrovsky National Research Center of Surgery, Moscow, Russia.
authors.forename: Alexey
authors.initials: A
authors.lastname: Tsyganov
authors.affiliation: EP Solutions SA, Yverdon-les-Bains, Switzerland.
authors.forename: Vitaly
authors.initials: V
authors.lastname: Kalinin
authors.affiliation: Department of Medicine, University Medical Center Mannheim, Mannheim, Germany.|German Center for Cardiovascular Research (DZHK), Partner Site Heidelberg/Mannheim, Mannheim, Germany.
authors.forename: Erol
authors.initials: E
authors.lastname: Tülümen
authors.affiliation: Department of Medicine, University Medical Center Mannheim, Mannheim, Germany.|German Center for Cardiovascular Research (DZHK), Partner Site Heidelberg/Mannheim, Mannheim, Germany.
authors.forename: Theano
authors.initials: T
authors.lastname: Papavassiliu
authors.affiliation: Department of Medicine, University Medical Center Mannheim, Mannheim, Germany.|German Center for Cardiovascular Research (DZHK), Partner Site Heidelberg/Mannheim, Mannheim, Germany.
authors.forename: Christina
authors.initials: C
authors.lastname: Dösch
authors.affiliation: Department of Medicine, University Medical Center Mannheim, Mannheim, Germany.|German Center for Cardiovascular Research (DZHK), Partner Site Heidelberg/Mannheim, Mannheim, Germany.
authors.forename: Volker
authors.initials: V
authors.lastname: Liebe
authors.affiliation: Department of Medicine, University Medical Center Mannheim, Mannheim, Germany.|German Center for Cardiovascular Research (DZHK), Partner Site Heidelberg/Mannheim, Mannheim, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Kuschyk
authors.affiliation: Department of Medicine, University Medical Center Mannheim, Mannheim, Germany.|German Center for Cardiovascular Research (DZHK), Partner Site Heidelberg/Mannheim, Mannheim, Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Röger
authors.affiliation: Department of Medicine, University Medical Center Mannheim, Mannheim, Germany.|German Center for Cardiovascular Research (DZHK), Partner Site Heidelberg/Mannheim, Mannheim, Germany.
authors.forename: Ibrahim
authors.initials: I
authors.lastname: El-Battrawy
authors.affiliation: Department of Medicine, University Medical Center Mannheim, Mannheim, Germany.|German Center for Cardiovascular Research (DZHK), Partner Site Heidelberg/Mannheim, Mannheim, Germany.
authors.forename: Ibrahim
authors.initials: I
authors.lastname: Akin
authors.affiliation: Petrovsky National Research Center of Surgery, Moscow, Russia.
authors.forename: Marina
authors.initials: M
authors.lastname: Yakovleva
authors.affiliation: Petrovsky National Research Center of Surgery, Moscow, Russia.|Pirogov Russian National Research Medical University, Moscow, Russia.
authors.forename: Elena
authors.initials: E
authors.lastname: Zaklyazminskaya
authors.affiliation: Petrovsky National Research Center of Surgery, Moscow, Russia.
authors.forename: Anna
authors.initials: A
authors.lastname: Shestak
authors.affiliation: Petrovsky National Research Center of Surgery, Moscow, Russia.
authors.forename: Stanislav
authors.initials: S
authors.lastname: Kim
authors.affiliation: EP Solutions SA, Yverdon-les-Bains, Switzerland.
authors.forename: Mikhail
authors.initials: M
authors.lastname: Chmelevsky
authors.affiliation: Department of Medicine, University Medical Center Mannheim, Mannheim, Germany.|German Center for Cardiovascular Research (DZHK), Partner Site Heidelberg/Mannheim, Mannheim, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Borggrefe
mesh_terms: D000328:Adult; D000404:Ajmaline; D000889:Anti-Arrhythmia Agents; D053840:Brugada Syndrome / Q000503:physiopathology*; D002037:Bundle-Branch Block / Q000503:physiopathology*; D016022:Case-Control Studies; D004562:Electrocardiography; D004699:Endocardium / Q000503:physiopathology*; D056149:Epicardial Mapping; D005260:Female; D006321:Heart / Q000503:physiopathology; D006352:Heart Ventricles / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D055815:Young Adult
chemical_list: D000889:Anti-Arrhythmia Agents; D000404:Ajmaline
keywords: Brugada syndrome; ajmaline challenge; arrhythmia; depolarization; electrocardiography; endocardium; epicardium; repolarization; right bundle branch block; right ventricular outflow tract; sudden death