Utility of Right-Electrocardiogram Chest Leads in Localization of Accessory Pathways in Patients with Wolf-Parkinson-White Syndrome

Abstract

Abstract Background Prediction of the precise location of an Accessory Pathway (AP) prior to the ablation procedure is of clinical importance. Several algorithms have been published to localize the AP on a surface 12-lead electrocardiogram (ECG). Most of them are based on analysis of delta wave morphology or QRS polarity. However, they are somewhat complicated, and an accurate determination of the delta wave morphology or QRS polarity are occasionally difficult, and their accuracy are still limited. Recently a new published algorithm using right-sided ECG chest leads for the prediction site of an AP is figured out and still under study for measuring its accuracy. Aim of the Work The aim of this study is to evaluate the accuracy of the utility of rightsided ECG Chest leads in the localization of APs in patients with manifest pre-excitation pattern in 12-lead ECG in prospective manner. Patients and Methods This study included 35 patients in whom successful ablation of manifest Wolff-Parkinson-White (WPW) syndrome was performed in prospective manner. Standard 12-lead ECG and right-sided chest ECG waveforms were recorded before the procedure. Results There were 13, 10, and 12 patients with left, right, and septal APs, respectively. All left AP patients had type A (RS morphology) in V1 and 12 of them in V4R leads, only 1 had type B in V4R lead. Of the 10 right AP patients, 5 had type B (rS morphology) in V1 while all 10 patients had type B in V4R. Of the 12 septal AP patients, 9 had type C (QS or Qr morphology) in V1, while 2 of the 12 patients had type B, and 1 of 12 patients had type A. All the 12 septal AP patients had type C in V4R. Conclusions The QRS morphology of V1 and V4R leads could predict the site of AP in patients with WPW syndrome with overall accuracy of 85.7% and 98%, respectively. Abbreviations AP: Accessory Pathway; ECG: Electrocardiogram; EPS: Electrophysiology study; RF: Radiofrequency; WPW: Wolff-Parkinson-White