A simple ECG algorithm using only the R/S ratio in leads V1, V2, and aVF accurately localized accessory pathways with an overall sensitivity of 94% and specificity of 98%.
Observational (n=142)
Abstract Background Several algorithms for localizing accessory pathways (APs) are based on the delta wave morphology, R/S ratio, and QRS polarity. However, they are somewhat complicated, and an accurate determination of the delta wave morphology is occasionally difficult. The aims of this study were to develop a simple algorithm for localizing APs using only the R/S ratio, and to test the accuracy of the algorithm prospectively. Methods We studied 142 patients with a single anterogradely conducting AP on a 12‐lead ECG. R/S ratios were analyzed in leads V1, V2, and aVF (R/S‐V1, R/S‐V2, and R/S‐aVF). AP locations were divided into five regions based on fluoroscopic anatomy. Results A new algorithm was developed by correlating R/S‐V1, R/S‐V2, and R/S‐aVF with successful ablation sites in 88 initial consecutive patients. All 55 patients with left free wall APs showed R/S‐V1 ≥0.5, and 47 (98%) of 48 patients with left anterior or lateral APs showed R/S‐aVF ≥1. In contrast, all seven patients with left posterolateral or posterior APs showed R/S‐aVF <1. All nine patients with right‐and‐left midseptal or posteroseptal APs showed R/S‐V1 <0.5 and R/S‐V2 ≥0.5. Of 12 patients with right anterior, lateral or anteroseptal APs, 10 (83%) showed R/S‐V1 <0.5, R/S‐V2 <0.5 and R/S‐aVF ≥1. Finally, nine (75%) of 12 patients with right posterolateral or posterior APs showed R/S‐V1 <0.5, R/S‐V2 <0.5, and R/S‐aVF <1. Then this algorithm was tested prospectively in 54 patients. Overall, the sensitivity was 94%, and the specificity was 98%. Conclusions This ECG algorithm provides a simple and accurate way to identify the AP localization.
Taguchi et al. (Sun,) conducted a observational in Wolff-Parkinson-White syndrome (n=142). R/S ratio-based ECG algorithm vs. Fluoroscopic anatomy (successful ablation sites) was evaluated on Algorithm sensitivity and specificity for localizing accessory pathways. A simple ECG algorithm using only the R/S ratio in leads V1, V2, and aVF accurately localized accessory pathways with an overall sensitivity of 94% and specificity of 98%.