A FAST AND RELIABLE ALGORITHM TO LOCALIZE ACCESSORY PATHWAYS BASED ONTHE POLARITY OF THE QRS COMPLEX ON THE SURFACE ECG DURING SINUS RHYTHM

Background: Many criteria have been published to localize accessory pa thways from the 12-lead ECG during sinus rhythm. This study analyzed w hether the localization of an accessory pathway could be predicted by using the polarity of the QRS complex during sinus rhythm on the surfa ce EGG, instead of the delta wave polarity as used in many reports. Me thods: The ECGs of 140 patients with an overt and single accessory pat hway were evaluated. Eight localizations were taken into account. The precise location was previously known from successful radiofrequency a blation sites. Results: In 128 patients (92%), the new algorithm allow ed an accurate diagnosis of the site of implantation of the accessory pathway. Conclusion: Analysis of the polarity of the QRS complex on fi ve electrocardiographic leads provides an easy, fast and reliable way to localize accessory pathways during sinus rhythm.