title: Sinus rhythm detection of conducting channels and ventricular tachycardia isthmus in arrhythmogenic right ventricular cardiomyopathy.
abstract: BACKGROUND
  The identification of conducting channels (CCs) based on its relative high voltage or the presence of electrograms with delayed components has been proposed for substrate-guided scar-related ventricular tachycardia (VT) ablation. The relationship of these channels with the VT isthmuses remains unclear.
  
  
  OBJECTIVE
  To assess the link between CCs identified during sinus rhythm (SR) and VT isthmuses in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC).
  
  
  METHODS
  Twenty-two consecutive patients with ARVC undergoing substrate-guided VT ablation (scar dechanneling technique) were analyzed. High-density endocardial and epicardial electroanatomic maps were obtained during SR. Standard bipolar cutoff values (0.5-1.5 and <0.5 mV) were used to define border zone and dense scar. The CCs were identified by voltage threshold adjustment (voltage channels) or by tagging the electrograms with delayed components that are sequentially activated (late potential channels).
  
  
  RESULTS
  A total of 87 CCs were identified; 65 (74.7%) of them on the epicardial surface. Twenty-four (27.6%) CCs were voltage channels, and compared with late potential CCs, these had a higher bipolar voltage (0.96 [0.48-1.29] mV vs 0.39 [0.26-0.50] mV; P < .001] and required more radiofrequency applications (5 [4-7] vs 3 [2-5]; P = .048]. Eighteen (90%) of 20 identified VT isthmuses were located on the epicardium. Only 8 (40%) VT isthmuses were related to a voltage CC. The remaining 12 (60%) VT isthmuses were linked to a late potential CC.
  
  
  CONCLUSIONS
  Late potential CCs more frequently act as the VT substrate in ARVC and therefore should also be considered to guide SR substrate-guided ablation.
authors.affiliation: Arrhythmia Section, Cardiology Department, Thorax Institute, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain; IDIBAPS (Institut d'Investigació Agustí Pi i Sunyer), Barcelona, Spain.
authors.forename: Juan
authors.initials: J
authors.lastname: Fernández-Armenta
authors.affiliation: Arrhythmia Section, Cardiology Department, Thorax Institute, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain; IDIBAPS (Institut d'Investigació Agustí Pi i Sunyer), Barcelona, Spain.
authors.forename: David
authors.initials: D
authors.lastname: Andreu
authors.affiliation: Arrhythmia Section, Cardiology Department, Thorax Institute, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain; IDIBAPS (Institut d'Investigació Agustí Pi i Sunyer), Barcelona, Spain.
authors.forename: Diego
authors.initials: D
authors.lastname: Penela
authors.affiliation: Arrhythmia Section, Cardiology Department, Thorax Institute, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain; IDIBAPS (Institut d'Investigació Agustí Pi i Sunyer), Barcelona, Spain.
authors.forename: Emilce
authors.initials: E
authors.lastname: Trucco
authors.affiliation: Arrhythmia Section, Cardiology Department, Thorax Institute, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain; IDIBAPS (Institut d'Investigació Agustí Pi i Sunyer), Barcelona, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Cipolletta
authors.affiliation: Arrhythmia Section, Cardiology Department, Thorax Institute, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain; IDIBAPS (Institut d'Investigació Agustí Pi i Sunyer), Barcelona, Spain.
authors.forename: Elena
authors.initials: E
authors.lastname: Arbelo
authors.affiliation: Arrhythmia Section, Cardiology Department, Thorax Institute, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain; IDIBAPS (Institut d'Investigació Agustí Pi i Sunyer), Barcelona, Spain.
authors.forename: Paola
authors.initials: P
authors.lastname: Berne
authors.affiliation: Arrhythmia Section, Cardiology Department, Thorax Institute, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain; IDIBAPS (Institut d'Investigació Agustí Pi i Sunyer), Barcelona, Spain.
authors.forename: Jose
authors.initials: J
authors.lastname: María Tolosana
authors.affiliation: Arrhythmia Unit, Cardiology Department, Hospital Universitario Virgen del Rocío, Seville, Spain.
authors.forename: Alonso
authors.initials: A
authors.lastname: Pedrote
authors.affiliation: Arrhythmia Section, Cardiology Department, Thorax Institute, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain; IDIBAPS (Institut d'Investigació Agustí Pi i Sunyer), Barcelona, Spain.
authors.forename: Josep
authors.initials: J
authors.lastname: Brugada
authors.affiliation: Arrhythmia Section, Cardiology Department, Thorax Institute, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain; IDIBAPS (Institut d'Investigació Agustí Pi i Sunyer), Barcelona, Spain.
authors.forename: Lluis
authors.initials: L
authors.lastname: Mont
authors.affiliation: Arrhythmia Section, Cardiology Department, Thorax Institute, Hospital Clínic, Universitat de Barcelona, Barcelona, Spain; IDIBAPS (Institut d'Investigació Agustí Pi i Sunyer), Barcelona, Spain. Electronic address: berruezo@clinic.ub.es.
authors.forename: Antonio
authors.initials: A
authors.lastname: Berruezo
mesh_terms: D000328:Adult; D019571:Arrhythmogenic Right Ventricular Dysplasia / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery; D018780:Body Surface Potential Mapping / Q000379:methods*; D017115:Catheter Ablation; D004562:Electrocardiography; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology* / Q000601:surgery; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D017180:Tachycardia, Ventricular / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery; D016896:Treatment Outcome
keywords: Arrhythmogenic right ventricular cardiomyopathy; Conducting channels; Epicardial ablation; Radiofrequency ablation; Substrate-guided ablation; Ventricular tachycardia