Background

Altered ventricular depolarization due to manifest accessory pathway conduction (ie, 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 postablation T-wave vector “remembers” the pre-excited QRS vector. In adults, these abnormalities can be misinterpreted as ischemia leading to unnecessary interventions. To date, no comprehensive studies have evaluated this phenomenon in the pediatric population.

Objective

The purpose of this study was to define TWM in the pediatric population, identify preablation risk factors, and delineate the timeline of recovery.

Methods

Pre- and postablation electrocardiograms (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 preablation ECG features with the outcome of TWM.

Results

TWM was present in 42% of pediatric patients, with resolution occurring within 3 months of ablation. Preablation QRS axis <0° was a strong predictor of TWM (odds ratio [OR] 15.2; 95% confidence interval [CI] 5.7–40), followed by posteroseptal pathway location (right posteroseptal—OR 8.9; 95% CI 4.2–18.8; left posteroseptal—OR 6.1; 95% CI 1.7–22.3). The degree of pre-excitation had a modest association with the development of TWM. No adverse events were observed.

Conclusion

TWM is less common in children compared to adults, and normalization occurred within 3 months postablation. The most predictive features for the development of TWM include a leftward pre-excited QRS axis and posteroseptal pathway location.

中文翻译：

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Wolff-Parkinson-White 综合征旁路消融后的小儿 T 波记忆

背景

由于明显的旁路传导（即 Wolff-Parkinson-White 综合征）导致的心室去极化改变导致通路消融后持续存在的复极化异常。T 波记忆(TWM)一词已应用于这些变化，因为消融后 T 波矢量“记住”了预激 QRS 矢量。在成人中，这些异常可能被误解为局部缺血，导致不必要的干预。迄今为止，还没有全面的研究在儿科人群中评估过这种现象。

客观的

本研究的目的是在儿科人群中定义 TWM，确定消融前的危险因素，并描绘恢复的时间表。

方法

在 5 年的时间内对 ≤25 岁患者的消融前后心电图 (ECG) 进行了分析。额面 QTc 间期、T 波轴、QRST 角和 T 波倒置用于识别 TWM 患者。进行单变量分析以确定消融前 ECG 特征与 TWM 结果的关联。

结果

TWM 存在于 42% 的儿科患者中，消融后 3 个月内消退。消融前 QRS 轴 <0° 是 TWM 的强预测因子（比值比 [OR] 15.2；95% 置信区间 [CI] 5.7–40），其次是后间隔通路位置（右侧后间隔 - OR 8.9；95% CI 4.2–18.8 ; 左后间隔—OR 6.1; 95% CI 1.7–22.3)。预激的程度与 TWM 的发展有适度的关联。没有观察到不良事件。

结论

与成人相比，TWM 在儿童中较少见，并且在消融后 3 个月内恢复正常。TWM 发展的最具预测性的特征包括左向预激 QRS 轴和后间隔通路位置。