title: A diagnostic algorithm to optimize data collection and interpretation of Ripple Maps in atrial tachycardias.
abstract: BACKGROUND
  Ripple Mapping (RM) is designed to overcome the limitations of existing isochronal 3D mapping systems by representing the intracardiac electrogram as a dynamic bar on a surface bipolar voltage map that changes in height according to the electrogram voltage-time relationship, relative to a fiduciary point.
  
  
  OBJECTIVE
  We tested the hypothesis that standard approaches to atrial tachycardia CARTO™ activation maps were inadequate for RM creation and interpretation. From the results, we aimed to develop an algorithm to optimize RMs for future prospective testing on a clinical RM platform.
  
  
  METHODS
  CARTO-XP™ activation maps from atrial tachycardia ablations were reviewed by two blinded assessors on an off-line RM workstation. Ripple Maps were graded according to a diagnostic confidence scale (Grade I - high confidence with clear pattern of activation through to Grade IV - non-diagnostic). The RM-based diagnoses were corroborated against the clinical diagnoses.
  
  
  RESULTS
  43 RMs from 14 patients were classified as Grade I (5 [11.5%]); Grade II (17 [39.5%]); Grade III (9 [21%]) and Grade IV (12 [28%]). Causes of low gradings/errors included the following: insufficient chamber point density; window-of-interest<100% of cycle length (CL); <95% tachycardia CL mapped; variability of CL and/or unstable fiducial reference marker; and suboptimal bar height and scar settings.
  
  
  CONCLUSIONS
  A data collection and map interpretation algorithm has been developed to optimize Ripple Maps in atrial tachycardias. This algorithm requires prospective testing on a real-time clinical platform.
authors.affiliation: Imperial College Healthcare NHS Trust, Praed Street, London W2 1NY, United Kingdom.
authors.forename: Michael
authors.initials: M
authors.lastname: Koa-Wing
authors.affiliation: Heart Rhythm Institute, University of Oklahoma Health Sciences Center, 1200 Everett Drive, Oklahoma City, USA.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nakagawa
authors.affiliation: Imperial College Healthcare NHS Trust, Praed Street, London W2 1NY, United Kingdom.
authors.forename: Vishal
authors.initials: V
authors.lastname: Luther
authors.affiliation: Imperial College Healthcare NHS Trust, Praed Street, London W2 1NY, United Kingdom.
authors.forename: Shahnaz
authors.initials: S
authors.lastname: Jamil-Copley
authors.affiliation: Imperial College Healthcare NHS Trust, Praed Street, London W2 1NY, United Kingdom.
authors.forename: Nick
authors.initials: N
authors.lastname: Linton
authors.affiliation: Imperial College Healthcare NHS Trust, Praed Street, London W2 1NY, United Kingdom.
authors.forename: Belinda
authors.initials: B
authors.lastname: Sandler
authors.affiliation: Imperial College Healthcare NHS Trust, Praed Street, London W2 1NY, United Kingdom.
authors.forename: Norman
authors.initials: N
authors.lastname: Qureshi
authors.affiliation: Imperial College Healthcare NHS Trust, Praed Street, London W2 1NY, United Kingdom.
authors.forename: Nicholas S
authors.initials: NS
authors.lastname: Peters
authors.affiliation: Imperial College Healthcare NHS Trust, Praed Street, London W2 1NY, United Kingdom.
authors.forename: D Wyn
authors.initials: DW
authors.lastname: Davies
authors.affiliation: Imperial College Healthcare NHS Trust, Praed Street, London W2 1NY, United Kingdom.
authors.forename: Darrel P
authors.initials: DP
authors.lastname: Francis
authors.affiliation: Heart Rhythm Institute, University of Oklahoma Health Sciences Center, 1200 Everett Drive, Oklahoma City, USA.
authors.forename: Warren
authors.initials: W
authors.lastname: Jackman
authors.affiliation: Imperial College Healthcare NHS Trust, Praed Street, London W2 1NY, United Kingdom. Electronic address: p.kanagaratnam@imperial.ac.uk.
authors.forename: Prapa
authors.initials: P
authors.lastname: Kanagaratnam
mesh_terms: D000368:Aged; D000465:Algorithms; D017115:Catheter Ablation / Q000379:methods; D002921:Cicatrix / Q000601:surgery; D022062:Electrophysiologic Techniques, Cardiac / Q000379:methods*; D005260:Female; D006329:Heart Conduction System / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000295:instrumentation / Q000379:methods; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013612:Tachycardia, Ectopic Atrial / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology; D013617:Tachycardia, Supraventricular / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology / Q000601:surgery
keywords: Ablation; Atrial tachycardia; Mapping; Ripple Mapping