Gellert Kapuaola S, Rautaharju Pentti, Snyder Michelle L, Whitsel Eric A, Matsushita Kunihiro, Heiss Gerardo, Soliman Elsayed Z
Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC.
Department of Public Health Sciences, Epidemiological Cardiology Research Center (EPICARE), Wake Forest University School of Medicine, Winston Salem, NC.
J Electrocardiol. 2014 May-Jun;47(3):356-61. doi: 10.1016/j.jelectrocard.2014.03.002. Epub 2014 Mar 6.
The electrocardiographic (ECG) Tpeak-Tend interval (TpTe) is associated with arrhythmias and sudden cardiac death. TpTe offers a supplementary measure for the QT interval (QT), yet its repeatability has not been established.
Evaluate short-term repeatability of TpTe and QT.
Four ECGs were obtained on sixty participants. The sources of variation, intra-class correlation coefficient (ICC) - an index of reproducibility - and minimal detectable change (MDC) were estimated for TpTe and QT. The impact of repeated measurements on repeatability was estimated for a hypothetical clinical trial designed to detect drug-induced prolongation of TpTe and QT.
We used heart rate-adjusted QT [(QT)a] but TpTe in the study group was rate-invariant. The ICC [95% confidence interval (CI)] was 0.77 (0.69, 0.85) for TpTe, 0.75 (0.65, 0.85) for QT and 0.60 (0.47, 0.73) for (QT)a. The MDC (ms) was 21, 32 and 26 for TpTe, QT and (QT)a respectively.
TpTe has excellent repeatability supporting its use as a supplement to QT in observational and clinical studies.
心电图（ECG）的T波峰 - T波终末间期（TpTe）与心律失常和心源性猝死相关。TpTe为QT间期（QT）提供了一种补充测量方法，但其重复性尚未得到证实。
评估TpTe和QT的短期重复性。
对60名参与者获取4份心电图。估计TpTe和QT的变异来源、组内相关系数（ICC）——一种再现性指标——以及最小可检测变化（MDC）。针对一项旨在检测药物诱导的TpTe和QT延长的假设性临床试验，估计重复测量对重复性的影响。
我们在研究组中使用心率校正后的QT[（QT）a]，但TpTe不受心率影响。TpTe的ICC[95%置信区间（CI）]为0.77（0.69，0.85），QT为0.75（0.65，0.85），（QT）a为0.60（0.47，0.73）。TpTe、QT和（QT）a的MDC（毫秒）分别为21、32和26。
TpTe具有出色的重复性，支持其在观察性研究和临床研究中作为QT的补充指标使用。
