title: Localizing the accessory pathway in ventricular preexcitation patients using a score based algorithm.
abstract: OBJECTIVE
  Clinical data was analyzed to find an efficient way to localize the accessory pathway in patients with ventricular preexcitation.
  
  
  METHODS
  The delta wave morphologies and ablation sites of 186 patients who underwent catheter ablation were analyzed and an algorithm ("locAP") to localize the accessory pathway was developed from the 84 data sets with a PQ interval ≤0.12s and a QRS width ≥0.12s. Fifty additional patients were included for a prospective validation. The locAP algorithm ranks 13 locations according to the likelihood that the accessory pathway is localized there. The algorithm is based on the locAP score which uses the standardized residuals of the available data sets.
  
  
  RESULTS
  The locAP algorithm's accuracy is 0.54 for 13 locations, with a sensitivity of 0.84, a specificity of 0.97, and a positive likelihood ratio of 24.94. If the two most likely locations are regarded, the accuracy rises to 0.79, for the three most likely locations combined the accuracy is 0.82. This new algorithm performs better than Milstein's, Fitzpatrick's, and Arruda's algorithm both in the original study population as well as in a prospective study.
  
  
  CONCLUSIONS
  The locAP algorithm is a valid and valuable tool for clinical practice in a cardiac electrophysiology laboratory. It could be shown that use of the locAP algorithm is favorable over the localizing algorithms that are in clinical use today.
authors.affiliation: Institute of Electrical, Electronic and Bioengineering, University for Health Sciences, Medical Informatics and Technology (UMIT), Hall in Tirol, Austria. lukas.rantner@gmail.com
authors.forename: L J
authors.initials: LJ
authors.lastname: Rantner
authors.forename: M C
authors.initials: MC
authors.lastname: Stühlinger
authors.forename: C N
authors.initials: CN
authors.lastname: Nowak
authors.forename: K
authors.initials: K
authors.lastname: Spuller
authors.forename: K
authors.initials: K
authors.lastname: Etsadashvili
authors.forename: X
authors.initials: X
authors.lastname: Stühlinger
authors.forename: T
authors.initials: T
authors.lastname: Berger
authors.forename: W
authors.initials: W
authors.lastname: Dichtl
authors.forename: R M
authors.initials: RM
authors.lastname: Gothe
authors.forename: G
authors.initials: G
authors.lastname: Fischer
authors.forename: F
authors.initials: F
authors.lastname: Hintringer
mesh_terms: D058606:Accessory Atrioventricular Bundle / Q000175:diagnosis / Q000473:pathology*; D000293:Adolescent; D000328:Adult; D000368:Aged; D000465:Algorithms; D017115:Catheter Ablation / Q000295:instrumentation; D016009:Chi-Square Distribution; D002648:Child; D004594:Electrophysiology / Q000295:instrumentation; D005260:Female; D006801:Humans; D007755:Laboratories, Hospital; D008297:Male; D008875:Middle Aged; D012680:Sensitivity and Specificity; D012984:Software; D018879:Ventricular Premature Complexes / Q000175:diagnosis / Q000473:pathology; D014927:Wolff-Parkinson-White Syndrome / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D055815:Young Adult