title: Differentiating the origin of outflow tract ventricular arrhythmia using a simple, novel approach.
abstract: BACKGROUND
  Numerous electrocardiographic (ECG) criteria have been proposed to identify localization of outflow tract ventricular arrhythmias (OT-VAs); however, in some cases, it is difficult to accurately localize the origin of OT-VA using the surface ECG.
  
  
  OBJECTIVE
  The purpose of this study was to assess a simple criterion for localization of OT-VAs during electrophysiology study.
  
  
  METHODS
  We measured the interval from the onset of the earliest QRS complex of premature ventricular contractions (PVCs) to the distal right ventricular apical signal (the QRS-RVA interval) in 66 patients (31 men aged 53.3 ± 14.0 years; right ventricular outflow tract [RVOT] origin in 37) referred for ablation of symptomatic outflow tract PVCs. We prospectively validated this criterion in 39 patients (22 men aged 52 ± 15 years; RVOT origin in 19).
  
  
  RESULTS
  Compared with patients with RVOT PVCs, the QRS-RVA interval was significantly longer in patients with left ventricular outflow tract (LVOT) PVCs (70 ± 14 vs 33.4±10 ms, P < .001). Receiver operating characteristic analysis showed that a QRS-RVA interval ≥49 ms had sensitivity, specificity, and positive and negative predictive values of 100%, 94.6%, 93.5%, and 100%, respectively, for prediction of an LVOT origin. The same analysis in the validation cohort showed sensitivity, specificity, and positive and negative predictive values of 94.7%, 95%, 95%, and 94.7%, respectively. When these data were combined, a QRS-RVA interval ≥49 ms had sensitivity, specificity, and positive and negative predictive values of 98%, 94.6%, 94.1%, and 98.1%, respectively, for prediction of an LVOT origin.
  
  
  CONCLUSIONS
  A QRS-RVA interval ≥49 ms suggests an LVOT origin. The QRS-RVA interval is a simple and accurate criterion for differentiating the origin of outflow tract arrhythmia during electrophysiology study; however, the accuracy of this criterion in identifying OT-VA from the right coronary cusp is limited.
authors.affiliation: Department of Electrophysiology, Heart Center, University of Leipzig, Leipzig, Germany.
authors.forename: Elena
authors.initials: E
authors.lastname: Efimova
authors.affiliation: Department of Electrophysiology, Heart Center, University of Leipzig, Leipzig, Germany.
authors.forename: Borislav
authors.initials: B
authors.lastname: Dinov
authors.affiliation: Department of Electrophysiology, Heart Center, University of Leipzig, Leipzig, Germany.
authors.forename: Willem-Jan
authors.initials: WJ
authors.lastname: Acou
authors.affiliation: Department of Electrophysiology, Heart Center, University of Leipzig, Leipzig, Germany.
authors.forename: Valentina
authors.initials: V
authors.lastname: Schirripa
authors.affiliation: Department of Electrophysiology, Heart Center, University of Leipzig, Leipzig, Germany.
authors.forename: Jelena
authors.initials: J
authors.lastname: Kornej
authors.affiliation: Department of Electrophysiology, Heart Center, University of Leipzig, Leipzig, Germany.
authors.forename: Jedrzej
authors.initials: J
authors.lastname: Kosiuk
authors.affiliation: Department of Electrophysiology, Heart Center, University of Leipzig, Leipzig, Germany.
authors.forename: Sascha
authors.initials: S
authors.lastname: Rolf
authors.affiliation: Department of Electrophysiology, Heart Center, University of Leipzig, Leipzig, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Sommer
authors.affiliation: Department of Electrophysiology, Heart Center, University of Leipzig, Leipzig, Germany.
authors.forename: Sergio
authors.initials: S
authors.lastname: Richter
authors.affiliation: Department of Electrophysiology, Heart Center, University of Leipzig, Leipzig, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Bollmann
authors.affiliation: Department of Electrophysiology, Heart Center, University of Leipzig, Leipzig, Germany.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Hindricks
authors.affiliation: Department of Electrophysiology, Heart Center, University of Leipzig, Leipzig, Germany. Electronic address: dr.arasharya@gmail.com.
authors.forename: Arash
authors.initials: A
authors.lastname: Arya
mesh_terms: D000328:Adult; D000368:Aged; D017115:Catheter Ablation / Q000379:methods; D061827:Dimensional Measurement Accuracy; D004562:Electrocardiography / Q000379:methods; D022062:Electrophysiologic Techniques, Cardiac / Q000379:methods; D005260:Female; D006329:Heart Conduction System / Q000473:pathology / Q000503:physiopathology; D006352:Heart Ventricles / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D012680:Sensitivity and Specificity; D017180:Tachycardia, Ventricular / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery; D018879:Ventricular Premature Complexes / Q000175:diagnosis / Q000503:physiopathology
keywords: Cardiac ablation; Left outflow tract; Outflow tract arrhythmia; QRS-RVA interval; Right outflow tract