Evaluating the efficacy of pre-ablation algorithms in WPW syndrome localization: a retrospective study

Abstract

Abstract Background and Objective Wolf-Parkinson-White (WPW) syndrome is a congenital condition that can be diagnosed at any age and may lead to dysrhythmias, most notably atrioventricular reentrant tachycardia (AVRT). Ablation of the accessory pathway responsible for the disorder has become a standard treatment approach. The success of ablation therapy is closely linked to accurately localizing the accessory pathway. Consequently, algorithms have been developed to predict the location of the accessory pathway using pre-ablation electrocardiography (ECG) parameters. This study aims to evaluate the predictive values of previously published algorithms. Method This study included 122 patients diagnosed with WPW syndrome who underwent successful ablation of a manifest accessory pathway at our university's cardiac electrophysiology laboratory between 2019 and 2023. We retrospectively examined these patients' baseline characteristics and their procedures' features. Additionally, a team analyzed their baseline electrocardiograms (ECGs) using the EASY-WPW, Pambrun, and St. George algorithms. The sensitivity, specificity, PPV, and NPV of these algorithms were then calculated based on the location of the accessory pathways identified during the patients’ ablation treatments. Results The median age of the patients in this study was 33 years (18 - 79). Among them, 65 patients (53.3%) were male (Table 1). Ablation treatment was conducted using a 3D mapping system for all included patients, considering only those who achieved acute procedural success for analysis. The most frequently observed accessory pathway localization was the posteroseptal region of the tricuspid annulus, found in 48 patients (39.3%). Regarding the accuracy of accessory pathway prediction, the EASY-WPW, Pambrun, and St. George algorithms demonstrated correct localization rates of 81%, 72%, and 62%, respectively. The efficacy of these predictions varied according to the specific localization of the accessory pathways (Table 2). Conclusion This study highlights the limitations of previously published algorithms in predicting the localization of accessory pathways in WPW syndrome. The notably lower success rates observed in our research, as compared to earlier studies, might be attributed to variations in how localization is defined across studies, differences in the interpretation of these algorithms by users, or evolving definitions of localization resulting from advancements in 3-dimensional mapping systems. Given these findings, there is a clear need for the development of new algorithms that incorporate current localization definitions and are validated in larger patient cohorts.