title: A fast and reliable algorithm to localize accessory pathways based on the polarity of the QRS complex on the surface ECG during sinus rhythm.
abstract: BACKGROUND
  Many criteria have been published to localize accessory pathways from the 12-lead ECG during sinus rhythm. This study analyzed whether the localization of an accessory pathway could be predicted by using the polarity of the QRS complex during sinus rhythm on the surface ECG, instead of the delta wave polarity as used in many reports.
  
  
  METHODS
  The ECGs of 140 patients with an overt and single accessory pathway were evaluated. Eight localizations were taken into account. The precise location was previously known from successful radiofrequency ablation sites.
  
  
  RESULTS
  In 128 patients (92%), the new algorithm allowed an accurate diagnosis of the site of implantation of the accessory pathway.
  
  
  CONCLUSIONS
  Analysis of the polarity of the QRS complex on five electrocardiographic leads provides an easy, fast and reliable way to localize accessory pathways during sinus rhythm.
mesh_terms: D000465:Algorithms; D001145:Arrhythmias, Cardiac / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D017115:Catheter Ablation; D004562:Electrocardiography / Q000145:classification / Q000706:statistics & numerical data; D005544:Forecasting; D006329:Heart Conduction System / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery; D006339:Heart Rate; D006801:Humans; D015588:Observer Variation; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014927:Wolff-Parkinson-White Syndrome / Q000473:pathology / Q000503:physiopathology / Q000601:surgery