A simple algorithm for localizing accessory pathways in patients with Wolff‐Parkinson‐White syndrome using only the R/S ratio

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.

Catheter ablation of complex arrhythmic anomalies: Bayes syndrome, Wolff-Parkinson-White syndrome, atrial and dilated cardiomyopathy

“…1,2 The definition of the pre-excitation syndrome, in this patient's case, may lead to misdiagnosis of pre-excitation. 6,8 The distance from the onset of P wave to onset of delta wave was 220 ms. However, taking into account the PQ corrected by P-wave conduction disturbances, the left atrial activation to delta wave was 110 ms; therefore, the criterion for pre-excitation syndrome was met.…”

Choice of Management in a Rare Case of Symptomatic Wolff-Parkinson-White (WPW) Syndrome Type B

“…Using 142 patients (88 post ablative ECGs of patients to construct algorithm and 54 patients for prospective testing of developed algorithm) they were able to just use only the R/S ratios with assessments of V1, V2 and aVF to correctly identify the correct aberrant pathway 51 out of 54 patients. This translated to an overall sensitivity of 94% and specificity of 98% [10]. Since its introduction in 1987, the utilization of RFA has now been recognized as a treatment of choice for WPW with tachyarrhythmias due to its relative safety and efficacy, as well as for the primary rationale of preventing the occurrence of sudden cardiac deaths [4] [11].…”

Development and evaluation of surface electrocardiogram in the septal accessory pathway localization in typical Wolff-Parkinson-White syndrome

“…Some ECG algorithms have been published to predict the location of left-sided or right-sided APs by positive or negative delta wave [1][2][3][4] . Besides, some other studies also diagnosed left or right-side APs by other ECG parameters such as R/S ratio < 0.5 or R/S > 0.5 in V1 lead 6 , positive or negative QRS complex in V1 to diagnose left or right-side APs 7 .…”