Pediatric T-wave memory after accessory pathway ablation in Wolff-Parkinson-White syndrome

Abstract Background Altered ventricular depolarization due to manifest accessory pathway conduction, Wolff-Parkinson-White syndrome, leads to repolarization abnormalities that persist after pathway ablation. The term T-wave memory (TWM) has been applied to these changes, as the post-ablation T-wave vector “remembers” the preexcited QRS vector. In adults, these abnormalities can be misinterpreted as ischemia leading to unnecessary interventions. To date, there have been no comprehensive studies evaluating this phenomenon in the pediatric population. Objective Define TWM in the pediatric population, identify pre-ablation risk factors, and delineate the timeline of recovery. Methods Pre- and post-ablation ECGs in patients ≤ 25 years were analyzed over a 5 year period. Frontal plane QTc interval, T-wave axis, QRST angle and T-wave inversions were used to identify patients with TWM. Univariate analysis was performed to determine the association of pre-ablation ECG features with the outcome of TWM. Results TWM was present in 42% of pediatric patients, with resolution occurring within 3 months of ablation. Pre-ablation QRS axis Conclusion TWM is less common in children compared to adults, and normalization occurred within 3 months post-ablation. The most predictive features for the development of TWM include a leftward preexcited QRS axis and posteroseptal pathway location.