title: Electrophysiologic characterization of local abnormal ventricular activities in postinfarction ventricular tachycardia with respect to their anatomic location.
abstract: BACKGROUND
  Local abnormal ventricular activities (LAVA) in patients with scar-related ventricular tachycardia (VT) may appear at any time during or after the far-field electrogram. Although they may be separated from the far-field signal by an isoelectric line and extend beyond the end of surface QRS, they may also appear fused or buried within the QRS.
  
  
  OBJECTIVE
  The purpose of this study was to characterize LAVA in postinfarction VT patients with respect to their anatomic locations.
  
  
  METHODS
  Thirty-one patients with postinfarction VT underwent mapping/ablation during sinus rhythm with a three-dimensional electroanatomic mapping system. From a total of 18,270 electrograms reviewed in all study subjects, 1104 LAVA (endocardium 839, epicardium 265) were identified and analyzed.
  
  
  RESULTS
  The interval from onset of QRS complex to ventricular electrogram (EGM onset) on the endocardium was significantly shorter than the epicardium (P < .001). EGM onset was shortest in the septal endocardium and longest in the inferior and lateral epicardium. There was a significant positive correlation between EGM onset and LAVA lateness as estimated by the interval from surface QRS onset to LAVA (r = 0.52, P < .001). LAVA were more frequently detected after the QRS complex in the epicardium (241/265 [91%]) than in the endocardium (551/839 [66%], P < .001). Only 43% of endocardial septal LAVA were detected after the QRS complex.
  
  
  CONCLUSIONS
  Lateness of LAVA is affected to a large extent by their locations. The chance of detecting late LAVA increases when electrogram onset is later. Substrate-based approach targeting delayed signals relative to the QRS complex may miss critical the arrhythmogenic substrate, particularly in the septum and other early-to-activate regions.
authors.affiliation: Department of Cardiac Electrophysiology, Hôpital Cardiologique du Haut-Lévêque, Université Victor Segalen Bordeaux II, Institut LYRIC, Equipex MUSIC, Bordeaux, France. Electronic address: yk.komat@gmail.com.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Komatsu
authors.forename: Matthew
authors.initials: M
authors.lastname: Daly
authors.forename: Frédéric
authors.initials: F
authors.lastname: Sacher
authors.forename: Nicolas
authors.initials: N
authors.lastname: Derval
authors.forename: Patrizio
authors.initials: P
authors.lastname: Pascale
authors.forename: Laurent
authors.initials: L
authors.lastname: Roten
authors.forename: Daniel
authors.initials: D
authors.lastname: Scherr
authors.forename: Amir
authors.initials: A
authors.lastname: Jadidi
authors.forename: Khaled
authors.initials: K
authors.lastname: Ramoul
authors.forename: Arnaud
authors.initials: A
authors.lastname: Denis
authors.forename: Laurence
authors.initials: L
authors.lastname: Jesel
authors.forename: Stephan
authors.initials: S
authors.lastname: Zellerhoff
authors.forename: Han S
authors.initials: HS
authors.lastname: Lim
authors.forename: Ashok
authors.initials: A
authors.lastname: Shah
authors.forename: Hubert
authors.initials: H
authors.lastname: Cochet
authors.forename: Mélèze
authors.initials: M
authors.lastname: Hocini
authors.forename: Michel
authors.initials: M
authors.lastname: Haïssaguerre
authors.forename: Pierre
authors.initials: P
authors.lastname: Jaïs
mesh_terms: D018780:Body Surface Potential Mapping / Q000379:methods*; D017115:Catheter Ablation; D004699:Endocardium / Q000503:physiopathology; D005260:Female; D005500:Follow-Up Studies; D006329:Heart Conduction System / Q000503:physiopathology* / Q000601:surgery; D006352:Heart Ventricles / Q000503:physiopathology; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000150:complications* / Q000503:physiopathology; D012189:Retrospective Studies; D017180:Tachycardia, Ventricular / Q000209:etiology / Q000503:physiopathology* / Q000601:surgery
keywords: 3D-EAM; Catheter ablation; ICD; LAVA; LV; Local abnormal ventricular activities; Mapping; Postmyocardial infarction; RV; Three-dimensional mapping; VT; Ventricular tachycardia; implantable cardioverter-defibrillator; left ventricle; local abnormal ventricular activities; right ventricle; three-dimensional electroanatomic mapping; ventricular tachycardia