title: Investigating a Novel Activation-Repolarisation Time Metric to Predict Localised Vulnerability to Reentry Using Computational Modelling.
abstract: Exit sites associated with scar-related reentrant arrhythmias represent important targets for catheter ablation therapy. However, their accurate location in a safe and robust manner remains a significant clinical challenge. We recently proposed a novel quantitative metric (termed the Reentry Vulnerability Index, RVI) to determine the difference between activation and repolarisation intervals measured from pairs of spatial locations during premature stimulation to accurately locate the critical site of reentry formation. In the clinic, the method showed potential to identify regions of low RVI corresponding to areas vulnerable to reentry, subsequently identified as ventricular tachycardia (VT) circuit exit sites. Here, we perform an in silico investigation of the RVI metric in order to aid the acquisition and interpretation of RVI maps and optimise its future usage within the clinic. Within idealised 2D sheet models we show that the RVI produces lower values under correspondingly more arrhythmogenic conditions, with even low resolution (8 mm electrode separation) recordings still able to locate vulnerable regions. When applied to models of infarct scars, the surface RVI maps successfully identified exit sites of the reentrant circuit, even in scenarios where the scar was wholly intramural. Within highly complex infarct scar anatomies with multiple reentrant pathways, the identified exit sites were dependent upon the specific pacing location used to compute the endocardial RVI maps. However, simulated ablation of these sites successfully prevented the reentry re-initiation. We conclude that endocardial surface RVI maps are able to successfully locate regions vulnerable to reentry corresponding to critical exit sites during sustained scar-related VT. The method is robust against highly complex and intramural scar anatomies and low resolution clinical data acquisition. Optimal location of all relevant sites requires RVI maps to be computed from multiple pacing locations.
authors.affiliation: Department of Biomedical Engineering, Division of Imaging Sciences & Biomedical Engineering, King's College London, London, United Kingdom.
authors.forename: Yolanda R
authors.initials: YR
authors.lastname: Hill
authors.affiliation: Department of Biomedical Engineering, Division of Imaging Sciences & Biomedical Engineering, King's College London, London, United Kingdom.
authors.forename: Nick
authors.initials: N
authors.lastname: Child
authors.affiliation: Department of Mechanical Engineering, University College London, London, United Kingdom.
authors.forename: Ben
authors.initials: B
authors.lastname: Hanson
authors.affiliation: Department of Systems and Data Analysis, Franhofer-Chalmers Centre, Gothenburg, Sweden.
authors.forename: Mikael
authors.initials: M
authors.lastname: Wallman
authors.affiliation: Academic Medical Center, Amsterdam, Netherlands.|L'Institut de RYthmologieet de Modelisation Cardiaque (LIRYC), Fondation Universite Bordeaux, Bordeaux, France.
authors.forename: Ruben
authors.initials: R
authors.lastname: Coronel
authors.affiliation: Institute of Biophysics, Medical University of Graz, Graz, Austria.
authors.forename: Gernot
authors.initials: G
authors.lastname: Plank
authors.affiliation: Department of Cardiology, Guys and St Thomas' Hospital, London, United Kingdom.
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Rinaldi
authors.affiliation: Department of Cardiology, Guys and St Thomas' Hospital, London, United Kingdom.
authors.forename: Jaswinder
authors.initials: J
authors.lastname: Gill
authors.affiliation: Department of Biomedical Engineering, Division of Imaging Sciences & Biomedical Engineering, King's College London, London, United Kingdom.|Department of Engineering, University of Auckland, Auckland, New Zealand.
authors.forename: Nicolas P
authors.initials: NP
authors.lastname: Smith
authors.affiliation: Department of Cardiovascular Sciences, University College London, London, United Kingdom.
authors.forename: Peter
authors.initials: P
authors.lastname: Taggart
authors.affiliation: Department of Biomedical Engineering, Division of Imaging Sciences & Biomedical Engineering, King's College London, London, United Kingdom.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Bishop
mesh_terms: D000818:Animals; D017115:Catheter Ablation / Q000379:methods*; D003198:Computer Simulation; D006352:Heart Ventricles / Q000033:anatomy & histology / Q000473:pathology / Q000601:surgery*; D006801:Humans; D008953:Models, Anatomic; D011817:Rabbits; D025321:Surgery, Computer-Assisted / Q000379:methods*; D017180:Tachycardia, Ventricular / Q000473:pathology / Q000601:surgery*