Sakaki Katsura, Ikeda Takanori, Miwa Yosuke, Miyakoshi Mutsumi, Abe Atsuko, Tsukada Takehiro, Ishiguro Haruhisa, Mera Hisaaki, Yusu Satoru, Yoshino Hideaki
Second Department of Internal Medicine, Kyorin University School of Medicine, Tokyo, Japan.
Heart Rhythm. 2009 Mar;6(3):332-7. doi: 10.1016/j.hrthm.2008.12.011. Epub 2008 Dec 7.
Time-domain T-wave alternans (TWA) is useful for identifying patients at risk for serious events after myocardial infarction.
The purpose of this study was to prospectively evaluate the utility of time-domain TWA measured from Holter ECGs in predicting cardiac mortality in patients with left ventricular (LV) dysfunction.
Two hundred ninety-five consecutive patients with LV dysfunction were enrolled in the study. Patients were divided into two groups: the ischemic group (n = 195) and the nonischemic group (n = 100). Time-domain TWA was assessed using the modified moving average method from routine 24-hour Holter ECGs recorded during daily activity. The maximal time-domain TWA voltage at heart rate <or=120 bpm in either lead V(5) or V(1) was derived and its value defined as positive when the voltage was >or=65 microV. The primary end-point was defined as cardiac mortality.
Mean maximal time-domain TWA voltage was 54 +/- 16 microV. During follow-up of 390 +/- 212 days, 27 patients (17 in the ischemic group and 10 in the nonischemic group) died of cardiac causes. Fifty-three patients (18%) were time-domain TWA positive and 242 (82%) were time-domain TWA negative. Univariate Cox proportional hazards analyses revealed that older age, New York Heart Association functional class III or IV, diabetes, renal dysfunction, nonsustained ventricular tachycardia, and time-domain TWA were associated with cardiac mortality. In multivariate analysis, time-domain TWA had the most significant value (hazard ratio = 17.1, P <.0001). This index also was significant in both subgroups (ischemic group: hazard ratio = 19.0, P <.0001; nonischemic group: hazard ratio = 12.3, P = .002).
Time-domain TWA measured from 24-hour Holter ECGs predicts cardiac mortality in patients with ischemic and nonischemic LV dysfunction.
时域T波交替（TWA）有助于识别心肌梗死后有严重事件风险的患者。
本研究的目的是前瞻性评估从动态心电图测量的时域TWA在预测左心室（LV）功能障碍患者心脏死亡率方面的效用。
连续纳入295例LV功能障碍患者。患者分为两组：缺血组（n = 195）和非缺血组（n = 100）。使用改良移动平均法从日常活动期间记录的常规24小时动态心电图评估时域TWA。得出心率≤120次/分时V(5)或V(1)导联的最大时域TWA电压，当电压≥65微伏时其值定义为阳性。主要终点定义为心脏死亡率。
平均最大时域TWA电压为54±16微伏。在390±212天的随访期间，27例患者（缺血组17例，非缺血组10例）死于心脏原因。53例患者（18%）时域TWA阳性，242例（82%）时域TWA阴性。单因素Cox比例风险分析显示，年龄较大、纽约心脏协会功能分级III或IV级、糖尿病、肾功能不全、非持续性室性心动过速和时域TWA与心脏死亡率相关。多因素分析中，时域TWA具有最显著价值（风险比 = 17.1，P <.0001）。该指标在两个亚组中均有显著意义（缺血组：风险比 = 19.0，P <.0001；非缺血组：风险比 = 12.3，P =.002）。
从24小时动态心电图测量的时域TWA可预测缺血性和非缺血性LV功能障碍患者的心脏死亡率。
