心电图(ECG)的T波反映心室复极。复极异质性与折返性心律失常有关。一些T波标记(包括QT间期)与室性心律失常有关,但是缺乏将此类标记与潜在的局部复极化时间(RT)不均匀性联系起来的研究。我们旨在研究几种T波标记与完整猪心脏中受控药物诱导的区域RT梯度的关系。
通过在放置在躯干罐中的四个心房起搏的猪Langendorff灌注心脏中局部输注多非利特和吡那地尔来产生复极化时间梯度。从躯干水箱的12导联心电图上,意思是,最大值,和QTtime的色散(max-min),JTtime,Tpeak-end,Twidth,TQratio,dV/dtmax,Tarea,夯实,并确定了T-上坡持续时间,以及引线V1和V6之间的上坡端差。
时间T波参数Tpeak-end,Twidth,和TQratio与RT梯度显示出显着的高度相关性,最好用平均值来反映。Tarea(mean,max和离散度)和dV/dtmax离散度仅显示中等显著相关性。T上坡持续时间显示出明显的相关性,特别是对于平均值。意思是,最大值,QTtime或离散度和V1-V6上坡端差与RT梯度无显著相关性。
复合12导联心电图T波参数Tpeak-end,Twidth,TQratio,上坡持续时间,Tarea与潜在的RT异质性表现出良好的相关性,而QTtime等标准临床指标不能反映局部RT异质性。因此,与传统QTtime度量相比,复合T波度量可以提供对心律失常易感性的更好见解。
The T wave of the electrocardiogram (ECG) reflects ventricular repolarization. Repolarization heterogeneity is associated with reentrant arrhythmias. Several T-wave markers (including QT interval) have been associated with ventricular arrhythmias, but studies linking such markers to underlying local repolarization time (RT) inhomogeneities are lacking. We aimed to investigate the relation of several T-wave markers to controlled drug-induced regional RT gradients in intact pig hearts.
Repolarization time gradients were created by regional infusion of dofetilide and
pinacidil in four atrially paced porcine Langendorff-perfused hearts placed inside a torso tank. From the 12-lead ECG on the torso tank, the mean, maximum, and dispersion (max-min) of QTtime , JTtime , Tpeak-end , Twidth , TQratio , dV/dtmax , Tarea , Tamp , and T-upslope duration were determined, as well as upslope end difference between leads V1 and V6 .
Temporal T-wave parameters Tpeak-end , Twidth, and TQratio show a significant and high correlation with RT gradient, best reflected by mean value. Tarea (mean, max and dispersion) and dV/dtmax dispersion show only a moderate significant correlation. T-upslope duration shows a significant correlation in particular for mean values. Mean, maximum, or dispersion of QTtime and V1 -V6 upslope end difference were not significantly correlated with RT gradient.
Composite 12-lead ECG T-wave parameters Tpeak-end , Twidth , TQratio , upslope duration, and Tarea show a good correlation with underlying RT heterogeneity, whereas standard clinical metrics such as QTtime do not reflect local RT heterogeneity. The composite T-wave metrics may thus provide better insights in arrhythmia susceptibility than traditional QTtime metrics.