B-PO05-195 POST-EXCITATION: EARLY REPOLARIZATION IN WOLF-PARKINSON-WHITE SYNDROME

Abstract

Life-threatening events (LTE) in Wolff-Parkinson White Syndrome (WPW) can occur pediatrics patients (pts) without high-risk accessory pathways (AP). Adults with WPW may have VF without atrial fibrillation. Early repolarization (ER) with specific patterns has been reported in adults with WPW, and has been associated with VF, but this has not been studied in children. Characterize ER in children with WPW and determine associations with clinical and electrophysiologic AP characteristics. All pts < 21 years with WPW who underwent ablation from 2017-2019 were included. ECGs were analyzed at baseline, maximal pre-excitation with adenosine, and post ablation. ER was defined by J point elevation ≥ 0.1 mV in 2 adjacent leads and notched vs. slurred pattern. ER lead distribution was characterized. 78 pts (mean age: 12 ± 3.7 yrs) with 13 AP locations were identified. ER was noted at baseline (26%), maximal pre-excitation (29%), and post ablation (45%). The predominant ER pattern at baseline was lateral (30%)/inferior (30%), inferior (52%) at maximal pre-excitation, and lateral (53%) post ablation. The predominant ER type was terminal QRS notching (see Table). Post-ablation ER appeared in 23% and disappeared in 4%. There was no association between ER and age, gender, symptoms, clinical arrhythmias, AP location, AP characteristics, inducible arrhythmias, or LTE. Of note, only 1 had a cardiac arrest. ER is more common in children with WPW pre and post ablation. There was no association between ER and electrophysiologic AP characteristics, suggesting ER is independent. Further evaluation is needed to determine if ER confers additional risk for LTE.