title: Outflow tract tachycardia with R/S transition in lead V3: six different anatomic approaches for successful ablation.
abstract: OBJECTIVE
  The aim of this study was to analyze different anatomic mapping approaches for successful ablation of outflow tract tachycardia with R/S transition in lead V(3).
  
  
  BACKGROUND
  Idiopathic ventricular tachycardia can originate from different areas in the outflow tract, including the right and left ventricular endocardium, the epicardium, the pulmonary artery, and the aortic sinus of Valsalva. Although electrocardiographic criteria may be helpful in predicting the area of origin, sometimes the focus is complex to determine, especially when QRS transition in precordial leads is in V(3).
  
  
  METHODS
  We analyzed surface electrocardiograms of 33 successfully ablated patients with outflow tract tachycardia: 20 from the right ventricular outflow tract (RVOT) and 13 from different sites. The R/S transition was determined, and the different anatomic approaches needed for successful catheter ablation were studied.
  
  
  RESULTS
  Overall, R/S transition in lead V(3) was present in 19 (58%) of all patients. In these patients, mapping was started and successfully completed in the RVOT in 11 of 19 (58%) patients. The remaining eight patients with R/S transition in lead V(3) needed five additional anatomic accesses for successful ablation: from the left ventricular outflow tract (n = 3), aortic sinus of Valsalva (n = 2), coronary sinus (n = 1), the epicardium via pericardial puncture (n = 1), and the trunk of the pulmonary artery (n = 1), respectively.
  
  
  CONCLUSIONS
  A R/S transition in lead V(3) is common. In patients with outflow tract tachycardia with R/S transition in lead V(3), a stepwise endocardial and epicardial mapping through up to six anatomic approaches can lead to successful radiofrequency catheter ablation.
authors.affiliation: University of Leipzig-Heart Center, Cardiology, Department of Electrophysiology, Struempellstrasse 39, D-04289 Leipzig, Germany. hilditanner@pop.agri.ch
authors.forename: Hildegard
authors.initials: H
authors.lastname: Tanner
authors.forename: Gerhard
authors.initials: G
authors.lastname: Hindricks
authors.forename: Petra
authors.initials: P
authors.lastname: Schirdewahn
authors.forename: Richard
authors.initials: R
authors.lastname: Kobza
authors.forename: Anja
authors.initials: A
authors.lastname: Dorszewski
authors.forename: Christopher
authors.initials: C
authors.lastname: Piorkowski
authors.forename: Jin-Hong
authors.initials: JH
authors.lastname: Gerds-Li
authors.forename: Hans
authors.initials: H
authors.lastname: Kottkamp
mesh_terms: D000328:Adult; D017115:Catheter Ablation / Q000379:methods*; D004562:Electrocardiography / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006329:Heart Conduction System / Q000503:physiopathology; D006352:Heart Ventricles / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D010496:Pericardium / Q000503:physiopathology; D011651:Pulmonary Artery / Q000503:physiopathology; D012850:Sinus of Valsalva / Q000503:physiopathology; D017180:Tachycardia, Ventricular / Q000503:physiopathology* / Q000601:surgery*; D016896:Treatment Outcome