Document Type : Original Article
Cardiac Electrophysiology Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, IR Iran.
Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, IR Iran.
Department of Biostatistics, School of public health, Iran University of Medical Silences, Tehran, IR Iran.
Background: Several algorithms have been designed for the localization of pre-ablation accessory pathways (APs) in Wolff–Parkinson–White (WPW) syndrome based on QRS or delta-wave polarity in different (electrocardiographic) ECG leads. Due to the difficulty of catheter placement in the tricuspid ring, leading to increased likelihoods of ablation failure and recurrence in right-sided APs, it is essential to design an algorithm to correctly predict the location of these APs before ablation.
Methods: In this retrospective study, 294 known WPW patients with right-sided APs who had clear pre-excitation in the 12-lead ECG were divided into 8 anatomic zones and were then studied using ECG and electrophysiological characteristics.
Results: An algorithm was designed based on the sum of QRS and delta-wave polarity in the V1 and inferior leads. The sensitivity and specificity of the proposed algorithm for predicting free-wall APs, including posterolateral and posterior APs, were 95% and 25%, respectively. Sensitivity and specificity were 72.7% and 95.8% for anterolateral and anterior APs, respectively, and 100% and 60% for lateral APs, respectively. In septal APs, the respective rates of sensitivity and specificity of the algorithm were 60% and 80% for the posteroseptal AP, 61% and 98% for the anteroseptal AP, and 31% and 90% for the midseptal AP.
Conclusions: The proposed algorithm provides a precise and simple way to differentiate between right-sided APs before performing ablation, thereby reducing ablation failure and recurrence. (Iranian Heart Journal 2021; 22(4): 71-79)