微伏 T 波电交替和电生理检查可预测不同的心律失常基质：对识别发生心源性猝死风险患者的意义。

Microvolt T-wave alternans and electrophysiologic testing predict distinct arrhythmia substrates: implications for identifying patients at risk for sudden cardiac death.

机构信息

Department of Cardiology, Soroka Medical Center & Faculty of Health Sciences, Ben-Gurion University, Beer-Sheva, Israel.

出版信息

Heart Rhythm. 2010 Jun;7(6):763-8. doi: 10.1016/j.hrthm.2010.02.012. Epub 2010 Feb 13.

DOI:10.1016/j.hrthm.2010.02.012

PMID:20156592

Abstract

BACKGROUND

Better risk stratification of patients receiving an implantable cardioverter-defibrillator (ICD) for primary prevention of sudden cardiac death (SCD) is needed. Although microvolt T-wave alternans (MTWA) and electrophysiologic study (EPS) are independent markers for SCD, the Alternans Before Cardioverter Defibrillator (ABCD) trial found the combination to be more predictive than either test alone.

OBJECTIVE

The purpose of this study was to test the hypothesis that EPS and MTWA measure different elements of the arrhythmogenic substrate and, therefore, predict distinct arrhythmia outcomes.

METHODS

The ABCD trial enrolled 566 patients with ischemic cardiomyopathy, left ventricular ejection fraction (LVEF) <or=0.40, and nonsustained ventricular tachycardia. All patients underwent both MTWA test and EPS. The performance of MTWA and EPS in predicting stable ventricular tachyarrhythmic events (S-VTEs) versus unstable ventricular tachyarrhythmic events (U-VTEs), defined as either polymorphic ventricular tachycardia or ventricular fibrillation, was analyzed using Kaplan-Meier event rates and the log rank test.

RESULTS

MTWA and EPS were abnormal in 71% and 39% of patients, respectively. There were 28 S-VTEs and 10 U-VTEs. MTWA was predictive of U-VTEs (event rate 2.7% in abnormals vs 0% in normals, P = .04), whereas EPS was not (1.5% vs 3.2%, P = .55). In contrast, EPS predicted S-VTEs (9.7% vs 2.2%, P <.01), but MTWA did not (5.5% vs 4.4%, P = .57). Whereas the extent of left ventricular contractile dysfunction alone (LVEF <or=0.30 vs LVEF 0.31-0.40) did not predict events, MTWA predicted events better than did EPS in subjects with LVEF <or=0.30. In contrast, EPS predicted events better than did MTWA test in subjects with LVEF >0.30.

CONCLUSION

The study data suggest that EPS and MTWA identify distinct arrhythmogenic substrates and, when used in combination, may better predict the complex electroanatomic substrates that underlie the risk for SCD.

摘要

背景

对于因心脏性猝死（SCD）进行一级预防而植入心脏复律除颤器（ICD）的患者，需要更好的风险分层。虽然微伏 T 波交替（MTWA）和电生理研究（EPS）是 SCD 的独立标志物，但“ABCD”试验发现，两者联合的预测价值优于单独使用任何一种检查。

目的

本研究旨在检验以下假说，即 EPS 和 MTWA 测量心律失常基质的不同元素，因此可以预测不同的心律失常结局。

方法

“ABCD”试验纳入了 566 例缺血性心肌病、左心室射血分数（LVEF）≤0.40 且伴有非持续性室性心动过速的患者。所有患者均行 MTWA 检查和 EPS。采用 Kaplan-Meier 事件率和对数秩检验分析 MTWA 和 EPS 在预测稳定型室性心律失常事件（S-VTEs）与不稳定型室性心律失常事件（U-VTEs）中的表现，后者定义为多形性室性心动过速或心室颤动。

结果

MTWA 和 EPS 异常的患者分别占 71%和 39%。发生 28 例 S-VTEs 和 10 例 U-VTEs。MTWA 可预测 U-VTEs（异常者的事件发生率为 2.7%，正常者为 0%，P =.04），而 EPS 则不能（1.5%比 3.2%，P =.55）。相反，EPS 可预测 S-VTEs（9.7%比 2.2%，P<.01），但 MTWA 不能（5.5%比 4.4%，P =.57）。尽管单独左心室收缩功能不全的严重程度（LVEF≤0.30 比 LVEF 0.31-0.40）不能预测事件，但在 LVEF≤0.30 的患者中，MTWA 比 EPS 更能预测事件。相反，在 LVEF>0.30 的患者中，EPS 比 MTWA 更能预测事件。