Pasala Tilak, Dettmer Mary, Leo Peter J, Laurita Kenneth R, Kaufman Elizabeth S
Heart and Vascular Research Center, MetroHealth Campus, Case Western Reserve University, Cleveland, OH, USA.
Heart and Vascular Research Center, MetroHealth Campus, Case Western Reserve University, Cleveland, OH, USA.
J Electrocardiol. 2016 Sep-Oct;49(5):733-9. doi: 10.1016/j.jelectrocard.2016.06.002. Epub 2016 Jun 9.
In experimental models, spatial dispersion of repolarization (DOR) due to discordant cellular alternans predisposes to ventricular fibrillation. To test the hypothesis that microvolt T-wave alternans (MTWA) in humans causes spatial DOR, we measured Tpeak-Tend interval (Tpe) and Tpe/QT ratio, electrocardiographic indices of spatial DOR.
Mean Tpe and Tpe/QT were compared in ischemic cardiomyopathy patients with positive and negative MTWA studies.
MTWA was positive in 12 and negative in 24 patients. Tpe and Tpe/QT were higher in MTWA+ subjects compared to MTWA- subjects during exercise (64.5±6.8 vs. 54.9±8.7ms, p=0.001 and 0.218±0.03 vs. 0.177±0.02, p=0.001) but not at rest.
Ischemic cardiomyopathy patients have increased Tpe and Tpe/QT when MTWA is induced during exercise, suggesting that MTWA causes increased spatial DOR in humans. Future studies are needed to determine if Tpe and Tpe/QT during exercise might predict increased risk of SCD alone or in combination with measurement of MTWA.
在实验模型中，由于不协调的细胞交替变化导致的复极空间离散（DOR）易引发心室颤动。为了验证人类微伏级T波交替变化（MTWA）会导致空间DOR这一假说，我们测量了Tpeak-Tend间期（Tpe）和Tpe/QT比值，这是空间DOR的心电图指标。
比较MTWA研究结果为阳性和阴性的缺血性心肌病患者的平均Tpe和Tpe/QT。
12例患者MTWA为阳性，24例为阴性。运动期间，MTWA阳性组的Tpe和Tpe/QT高于MTWA阴性组（分别为64.5±6.8 vs. 54.9±8.7ms，p = 0.001；0.218±0.03 vs. 0.177±0.02，p = 0.001），但静息时无此差异。
运动诱发MTWA时，缺血性心肌病患者的Tpe和Tpe/QT增加，提示MTWA会导致人类空间DOR增加。未来需要开展研究，以确定运动时的Tpe和Tpe/QT是否单独或与MTWA测量结果相结合，能够预测心脏性猝死风险增加。
