PC-577-04 ANTEROSEPTAL ACCESSORY PATHWAY: KILLING ONE BIRD WITH TWO STONES

Abstract

21 year old healthcare worker with frequent palpitations leading to frequent hospitalizations with elevated heart rates up to 210 bpm noted on her watch with pre-excitation on ECG consistent with anteroseptal accessory pathway (AS AP). Describe a case of achieving antegrade conduction block in the AS AP with retrograde ablation approach and achieving retrograde conduction block with antegrade ablation approach. N/A Electrophysiological maneuvers were performed including parahisian pacing, apical/basal pacing confirming an AS AP with antegrade and retrograde conduction. Orthodromic reentrant tachycardia (ORT) was easily inducible with burst A pacing. Due to close proximity of the earliest site to the HIS using antegrade approach, decision was made to use the retrograde approach which showed an early site without HIS signal in the non coronary cusp (NCC). Ablation in the NCC resulted in antegrade conduction block after 1.4 seconds and was no longer seen until the end of the case (Fig A&B). Repeating the prior maneuvers showed persistent retrograde conduction and patient was still easily inducible for ORT. Additional ablation in the NCC did not terminate retrograde conduction. Antegrade approach was used for further ablation opposite the NCC at the earliest retrograde A during ORT which resulted in termination of ORT after 0.5 seconds (Figure D). Repeat maneuvers showed no evidence of pathway conduction and the patient was non inducible for ORT. No events at six month follow up. AS AP with successful ablation of antegrade conduction from a retrograde approach and successful ablation of retrograde conduction from an antegrade approach.