Impact of a Novel Pre-Procedural ECG Schematic for Accessory Pathway Localization on Procedural Outcomes of Radiofrequency Catheter Ablation in Typical Wolff–Parkinson–White Syndrome

BACKGROUND/AIMS: This study aimed to evaluate the clinical efficacy, procedural metrics, and safety outcomes of radiofrequency catheter ablation (RFCA) for typical Wolff - Parkinson - White (WPW) syndrome utilizing a pre-procedural 12-lead surface electrocardiogram (ECG) schematic for accessory pathway (AP) localization in a Vietnamese cohort. METHODS: A prospective, descriptive study was performed on 109 consecutive patients with typical WPW syndrome undergoing electrophysiological study (EPS) and RFCA. A stepwise 12-lead ECG algorithm (the new schematic) was applied to predict the AP anatomical site prior to ablation, which was validated against intraprocedural electroanatomical mapping endpoints. Diagnostic performance (concordance between predicted and electrophysiologically confirmed AP locations) was evaluated. Operational metrics were compared with a historical control cohort (n=189) managed without the algorithm. RESULTS: All 109 patients (51.4% male, mean age 43.6 ± 14.9 years) presented with a single manifest AP (52 right-sided, 47.7%; 57 left-sided, 52.3%). The overall diagnostic accuracy of the ECG schematic for predicting the correct AP anatomical zone was 92.7% (101/109 cases). The acute procedural success rate was 100%. Right-sided AP ablations showed longer total procedure duration (52.9 ± 21.5 min vs. 44.9 ± 14.5 min, p < 0.05) higher total radiofrequency delivery time (368.1 ± 202.5 sec vs. 261.6 ± 110.6 sec, p < 0.01), and more RF applications (10.9 ± 8.3 vs. 5.7 ± 3.7, p < 0.001) than left-sided APs. Fluoroscopy time did not differ significantly between right- and left-sided groups (7.3 ± 4.2 min vs. 7.0 ± 3.8 min, p > 0.05). Compared with the historical control group (n=189), implementation of the ECG schematic was associated with reductions in total procedure duration (48.7 ± 18.5 min vs. 55.0 ± 29.7 min, p < 0.05) and fluoroscopy exposure (7.2 ± 4.0 min vs. 9.0 ± 5.0 min, p < 0.001). No major adverse cardiovascular events or permanent AV blocks occurred; one minor transient phrenic nerve response (0.9%) resolved spontaneously. CONCLUSION: The pre-procedural surface ECG prediction schematic provides reliable anatomical localization of APs in typical WPW syndrome. Its clinical application was associated with reduced total procedure duration and fluoroscopy exposure time, while maintaining a high acute success rate and a favorable safety profile.