title: An electrocardiographic scoring system for distinguishing right ventricular outflow tract arrhythmias in patients with arrhythmogenic right ventricular cardiomyopathy from idiopathic ventricular tachycardia.
abstract: BACKGROUND
  Ventricular arrhythmias in patients with arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) and idiopathic ventricular tachycardia (VT) can share a left bundle branch block/inferior axis morphology. We previously reported electrocardiogram characteristics during outflow tract ventricular arrhythmias that helped distinguish VT related to ARVD/C from idiopathic VT.
  
  
  OBJECTIVE
  To prospectively validate these criteria.
  
  
  METHODS
  We created a risk score by using a derivation cohort. Two experienced electrophysiologists blinded to the diagnosis prospectively scored patients with VT/premature ventricular contractions (PVCs) with left bundle branch block/inferior axis pattern in a validation cohort of 37 ARVD/C tracings and 49 idiopathic VT tracings. All patients with ARVD/C had their diagnosis confirmed based on the revised task force criteria. Patients with idiopathic VT were selected based on structurally normal hearts with documented right ventricular outflow tract VT successfully treated with ablation. The scoring system provides 3 points for sinus rhythm anterior T-wave inversions in leads V1-V3 and during ventricular arrhythmia: 2 points for QRS duration in lead I≥120 ms, 2 points for QRS notching, and 1 point for precordial transition at lead V5 or later.
  
  
  RESULTS
  A score of 5 or greater was able to correctly distinguish ARVD/C from idiopathic VT 93% of the time, with a sensitivity of 84%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 91%.
  
  
  CONCLUSIONS
  We describe a simple scoring algorithm that uses 12-lead electrocardiogram characteristics to effectively distinguish right ventricular outflow tract arrhythmias originating from patients with ARVD/C versus patients with idiopathic VT.
authors.affiliation: Division of Cardiology, University of California, San Francisco, CA 94143-1354, USA.
authors.forename: Kurt S
authors.initials: KS
authors.lastname: Hoffmayer
authors.forename: Prashant D
authors.initials: PD
authors.lastname: Bhave
authors.forename: Gregory M
authors.initials: GM
authors.lastname: Marcus
authors.forename: Cynthia A
authors.initials: CA
authors.lastname: James
authors.forename: Crystal
authors.initials: C
authors.lastname: Tichnell
authors.forename: Nagesh
authors.initials: N
authors.lastname: Chopra
authors.forename: Laura
authors.initials: L
authors.lastname: Moxey
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Krahn
authors.forename: Sanjay
authors.initials: S
authors.lastname: Dixit
authors.forename: William
authors.initials: W
authors.lastname: Stevenson
authors.forename: Hugh
authors.initials: H
authors.lastname: Calkins
authors.forename: Nitish
authors.initials: N
authors.lastname: Badhwar
authors.forename: Edward P
authors.initials: EP
authors.lastname: Gerstenfeld
authors.forename: Melvin M
authors.initials: MM
authors.lastname: Scheinman
mesh_terms: D000328:Adult; D019571:Arrhythmogenic Right Ventricular Dysplasia / Q000175:diagnosis* / Q000503:physiopathology; D018780:Body Surface Potential Mapping / Q000379:methods; D002037:Bundle-Branch Block / Q000175:diagnosis*; D015331:Cohort Studies; D016001:Confidence Intervals; D003937:Diagnosis, Differential; D004562:Electrocardiography; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012372:ROC Curve; D012107:Research Design; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D017180:Tachycardia, Ventricular / Q000175:diagnosis* / Q000503:physiopathology; D014694:Ventricular Outflow Obstruction / Q000175:diagnosis*