Tasic Jerneja, Zupan Igor
Department of Cardiology, University Clinical Centre Ljubljana, Ljubljana, Slovenia.
Pacing Clin Electrophysiol. 2009 Mar;32 Suppl 1:S155-7. doi: 10.1111/j.1540-8159.2008.02274.x.
T-wave alternans is an important identifier of patients at risk of sudden cardiac death (SCD), but the procedure usually requires stress testing. In this study, the variability of T-wave amplitude (TVAR) was evaluated at rest, as a risk stratifier for SCD.
This study included 57 patients in sinus rhythm and with a left ventricular ejection fraction < or =40%, of whom 34 (60%) received an implantable cardioverter-defibrillator (ICD) after surviving SCD, and 23 (40%) presented with ischemic or nonischemic cardiomyopathy and no history of SCD. A 20-minute high-resolution electrocardiographic recording for TVAR assessment was performed during supine rest. The vector magnitude was used as a primary lead for TVAR analysis.
The mean, median, and maximum (max) values of TVAR were measured. The patients with ICD had a lower max TVAR than the patients without ICD (67 vs 95 muV; P = 0.045), though the mean and median TVAR values were similar. By multivariate logistic analysis, max TVAR remained a predictor of SCD, after adjustments for potentially confounding factors (P = 0.044).
Max TVAR was a predictor of arrhythmic events in patients with dilated cardiomyopathy at rest.
T波交替是心脏性猝死（SCD）风险患者的重要识别指标，但该检查通常需要进行负荷试验。在本研究中，评估静息状态下的T波振幅变异性（TVAR），作为SCD的风险分层指标。
本研究纳入57例窦性心律且左心室射血分数≤40%的患者，其中34例（60%）在经历SCD后存活并接受了植入式心律转复除颤器（ICD）治疗，23例（40%）患有缺血性或非缺血性心肌病且无SCD病史。在仰卧休息期间进行20分钟的高分辨率心电图记录以评估TVAR。矢量大小用作TVAR分析的主要导联。
测量了TVAR的平均值、中位数和最大值（max）。ICD患者的max TVAR低于无ICD患者（67 μV对95 μV；P = 0.045），尽管TVAR的平均值和中位数相似。通过多因素逻辑分析，在对潜在混杂因素进行调整后，max TVAR仍然是SCD的预测指标（P = 0.044）。
Max TVAR是扩张型心肌病患者静息时心律失常事件的预测指标。
