Takasugi Nobuhiro, Matsuno Hiroko, Takasugi Mieko, Shinoda Koichi, Watanabe Takatomo, Ito Hiroyasu, Okura Hiroyuki, Verrier Richard L
Gifu University Hospital, Gifu, Japan.
Matsunami General Hospital, Gifu, Japan.
Ann Noninvasive Electrocardiol. 2019 Sep;24(5):e12670. doi: 10.1111/anec.12670. Epub 2019 Jun 26.
Ambulatory electrocardiogram (ECG)-based microvolt T-wave alternans values measured by the modified moving average method (MMA-TWA) can be disrupted by T-wave changes that mimic true repolarization alternans.
We investigated potential sources of measurement error by studying 19 healthy subjects (12 men; median age, 25) free of known heart disease with 36-month follow-up to establish freedom from significant arrhythmia or syncope. All participants underwent 24-hr continuous 12-lead ECG monitoring. Causes of automated MMA-TWA ≥42 µV episodes were classified based on visual inspection.
A total of 2,189 episodes of automated MMA-TWA episodes ≥42 µV were observed in all subjects (peak MMA-TWA: median, 94 μV; interquartile range, 81-112 μV). All episodes included one or more beats with T-wave deformation which lacked "repeating ABAB pattern" and therefore were identified as TWA measurement error. Causes of such error were categorized as: (a) artifact [72.6% (1,589/2,189), observed in 19 (100%) subjects], more frequently in limb than precordial leads; (b) T-wave changes due to changes in heart/body position [25.5% (559/2,189), observed in 14 (73.7%) subjects], frequently observed in leads V1-2; and (c) postextrasystolic T-wave changes [1.9% (41/2,189), observed in 2 (10.5%) subjects].
Relying only on automated MMA-TWA values obtained during ambulatory ECG monitoring can lead to incorrect measurement of TWA. Our findings offer the potential to reduce false-positive TWA results and to achieve more accurate detection of true repolarization alternans.
通过改良移动平均法（MMA-TWA）测量的基于动态心电图（ECG）的微伏级T波交替变化值可能会受到模拟真正复极交替变化的T波改变的干扰。
我们研究了19名无已知心脏病的健康受试者（12名男性；年龄中位数为25岁），对其进行了36个月的随访以确定无明显心律失常或晕厥，通过研究这些受试者来调查测量误差的潜在来源。所有参与者均接受了24小时连续12导联心电图监测。根据目视检查对自动MMA-TWA≥42µV发作的原因进行分类。
在所有受试者中总共观察到2189次自动MMA-TWA发作≥42µV（MMA-TWA峰值：中位数为94µV；四分位间距为81-112µV）。所有发作均包括一个或多个T波变形的搏动，这些搏动缺乏“重复ABAB模式”，因此被确定为TWA测量误差。此类误差的原因分类如下：（a）伪迹[72.6%（1589/2189），在19名（100%）受试者中观察到]，在肢体导联中比胸前导联更常见；（b）由于心脏/身体位置变化导致的T波改变[25.5%（559/2189），在14名（73.7%）受试者中观察到]，在V1-2导联中经常观察到；（c）早搏后T波改变[1.9%（41/2189），在2名（10.5%）受试者中观察到]。
仅依靠动态心电图监测期间获得的自动MMA-TWA值可能会导致TWA测量错误。我们的研究结果有可能减少TWA的假阳性结果，并实现对真正复极交替变化更准确的检测。
