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: Unknown etiology Background: 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 elucidated. Herein, we report 2 cases of WPW syndrome, wherein antegrade conduction was abolished first, followed by retrograde conduction. Case Reports: 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 radiofrequency ablation performed multiple times in the same vicinity abolished retrograde accessory pathway conduction. Conclusions: 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.

Anteroseptal accessory pathways: Killing one bird with two stones

“…Sawasaki et al reported two patients that required sequential ablations to achieve anterograde and retrograde conduction across a left lateral pathway and hypothesized that the initial ablation led to an incomplete lesion and a functional block in one direction. However, sequential ablations were in the same location or in the immediate vicinity of each other in their cases 18 . The patients we reported required sequential ablations in two separate anatomic locations making an incomplete lesion an unlikely explanation.…”

“…However, sequential ablations were in the same location or in the immediate vicinity of each other in their cases. 18 The patients we reported required sequential ablations in two separate anatomic locations making an incomplete lesion an unlikely explanation.…”