title: Development and validation of an ECG algorithm for identifying the optimal ablation site for idiopathic ventricular outflow tract tachycardia.
abstract: BACKGROUND
  Idiopathic ventricular outflow tract tachycardia or premature ventricular contractions (OT-VTs) can originate from several different sites in the outflow tract, including the left ventricular (LV) endocardium and epicardium. The aims of this study were (1) to develop an ECG algorithm to predict the origin of OT-VT and (2) to test prospectively the accuracy of the algorithm.
  
  
  RESULTS
  An algorithm was developed by correlating the 12-lead ECG findings with the catheter ablation site in 80 patients with OT-VT. The ECG characteristics of the QRS complex during the arrhythmia were analyzed. The catheter sites were verified by multi-plane fluoroscopy. The outflow tract was classified into six subdivisions: right ventricular (RV) septum, RV free wall, RV near the His-bundle region, LV endocardium, left sinus of Valsalva (LSV), and LV epicardium remote from the LSV. An OT-VT originating from the LV epicardium remote from the LSV was defined as an OT-VT in which the earliest ventricular activation was recorded at the LSV and radiofrequency ablation from the LSV failed. This algorithm subsequently was tested prospectively in 88 patients. Overall sensitivity was 88% and specificity was 95%. The positive and negative predictive values were 88% and 96%, respectively.
  
  
  CONCLUSIONS
  We describe a new ECG algorithm having a high sensitivity and specificity to identify the optimal ablation site for idiopathic ventricular outflow tachycardia or premature ventricular contractions.
authors.affiliation: Third Department of Internal Medicine, Fukui Medical University, Matsuoka, Fukui, Japan.
authors.forename: Sachiko
authors.initials: S
authors.lastname: Ito
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tada
authors.forename: Shigeto
authors.initials: S
authors.lastname: Naito
authors.forename: Kenji
authors.initials: K
authors.lastname: Kurosaki
authors.forename: Marehiko
authors.initials: M
authors.lastname: Ueda
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hoshizaki
authors.forename: Isamu
authors.initials: I
authors.lastname: Miyamori
authors.forename: Shigeru
authors.initials: S
authors.lastname: Oshima
authors.forename: Koichi
authors.initials: K
authors.lastname: Taniguchi
authors.forename: Akihiko
authors.initials: A
authors.lastname: Nogami
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000465:Algorithms; D017115:Catheter Ablation / Q000379:methods*; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D017180:Tachycardia, Ventricular / Q000150:complications / Q000175:diagnosis* / Q000601:surgery*; D018879:Ventricular Premature Complexes / Q000150:complications / Q000175:diagnosis* / Q000601:surgery*