Tehran University of Medical Sciences The Research in Heart Yield and Translational Medicine (RHYTHM) 3115-7270 20 2 2025 09 27 89 96 EN Maryam Moradian Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran Mohammad Rafie Khorgami Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran. Avisa Tabib Cardiogenetic Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran Mohammad Dalili Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran Fariba Rashidighader Assistant professor of pediatric cardiology , Rajaei cardiovascular medical and research center, school of medicine, Iran University of Medical Sciences Shabnam Boudagh Echocardiography research center،Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran Mohammad Mahdavi Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran Reza Abbaszadeh Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran Yasaman Khalili Assistant Professor of Community Medicine Heart Research Center Rajaie Cardiovascular, Medical and Research Center Soheila Hoseinzadeh Moghadam Department of Pediatric Cardiology, Rajaei Cardiovascular Research and Medical Center, School of Medicine, Iran University of Medical Sciences, Intersection of Niayesh Highway and Valiasr St, Tehran 1995614331, Iran. 2024 01 17 2025 05 04 Objective: To evaluate the impact of radiofrequency ablation (RFA) on dyssynchrony in children with Wolff-Parkinson-White (WPW) syndrome. Methods: This pre-post interventional study was conducted at Rajaie Cardiovascular Institute in Tehran, Iran, and included patients with WPW syndrome who had accessory pathways and were candidates for RFA. Demographic and baseline data, such as age and sex, were recorded. Patients underwent ECG studies and RFA of their accessory pathways. Twelve-lead ECG was performed before and one day after RFA. Standard echocardiographic views were obtained using a Vivid S60 system with appropriate transducers in 1D (M-mode) and 2D modes, along with Doppler evaluation. Intraventricular and interventricular dyssynchrony indices were assessed, and 2D strain analysis was performed. Data were analyzed using IBM SPSS Statistics for Windows, version 26.0. Results: This study included 54 patients with WPW syndrome, 17 of whom had ventricular dyssynchrony. Ablation significantly affected QRS duration, PR interval, fractional shortening, left ventricular ejection fraction, and septal-to-posterior wall motion delay but did not significantly alter interventricular mechanical delay. The most common accessory pathways were left lateral, right posteroseptal, and left posteroseptal. The location of the accessory pathway was not significantly associated with the occurrence of dyssynchrony. Conclusions: Based on the findings of this study, RF ablation eliminated dyssynchrony in all WPW patients and improved functional and strain parameters in this population. These improvements enhance cardiac function and reduce associated risks, particularly in pediatric patients. https://rhythm.tums.ac.ir/index.php/jthc/article/view/2005 https://rhythm.tums.ac.ir/index.php/jthc/article/download/2005/1201