Sequential abolition of antegrade and retrograde conduction in wolff-parkinson-white syndrome: A case series

Abstract

Case series Patients: Male, 15-year-old • Female, 19-year-old Final Diagnosis: Wolff-Parkinson-White (WPW) syndrome Symptoms: Palpitation Medication: — Clinical Procedure: — Specialty: Anatomy • Cardiology Objective: Background: Case Reports: Conclusions: Unknown etiology Radiofrequency ablation in cases of Wolff-Parkinson-White (WPW) syndrome is a relatively safe procedure that yields good results. However, the electrical characteristics of WPW syndrome have not yet been fully elucidat-ed. Herein, we report 2 cases of WPW syndrome, wherein antegrade conduction was abolished first, followed by retrograde conduction. Case 1: A 15-year-old boy who recently reported experiencing frequent palpitations was diagnosed with type A WPW syndrome by electrocardiography (ECG). Radiofrequency energy was delivered to the earliest activation site using an ablation catheter. This procedure abolished antegrade accessory pathway conduction in 6 seconds, and then the ablation was continued for 60 seconds; however, retrograde accessory pathway conduction remained intact. Hence, radiofrequency ablation was performed to further deliver radiofrequency energy to abolish the retrograde accessory pathway conduction. Case 2: A 19-year-old woman with palpitations since elementary school was diagnosed with type A WPW syndrome by ECG. Radiofrequency energy was delivered to the earliest activation site through an ablation catheter to abolish antegrade accessory pathway conduction in approximately 1 second, and then the ablation was continued for 60 seconds. Retrograde accessory pathway conduction was preserved, and further radiofrequen-cy ablation performed multiple times in the same vicinity abolished retrograde accessory pathway conduction. We managed 2 cases of WPW syndrome wherein antegrade and retrograde accessory pathway conduction were individually abolished. This phenomenon may have been caused by an incomplete lesion that resulted in a functional block.