Schmidt Matthias, Schneider Christian, Theissen Peter, Erdmann Erland, Schicha Harald
Department of Nuclear Medicine, University of Cologne, Germany.
Int J Cardiol. 2006 Nov 18;113(3):327-31. doi: 10.1016/j.ijcard.2005.11.044. Epub 2006 Jan 10.
There is controversy whether the measurement of QT dispersion might provide information about the presence and extent of ischaemic myocardium. It was the aim to analyse the diagnostic value of QT dispersion for the detection of myocardial ischaemia in comparison to Tl-201-SPECT.
100 patients were randomly selected from patients referred for Tl-201-SPECT. QT duration was measured in all 12 leads in the resting ECG and in the ECG either at maximal bicycle exercise or during peak dipyridamole stress. QT dispersion was calculated and correlated with parameters of ischaemia for all patients and for the bicycle exercise and the dipyridamole group separately.
25 patients had to be excluded from the analysis because QT dispersion could not be measured. Regression analysis did not show significant correlation neither for all 75 patients nor for the bicycle exercise nor for the dipyridamole group correlating grade of myocardial ischaemia, number of ischaemic segments and summed ischaemic stress score with QT dispersion in the resting or the stress ECG and QTd and there was no significant difference between groups.
QT dispersion could not be measured in 25/100 patients (25%). In the remaining patients QT dispersion did not correlate with the extent or grade of myocardial ischaemia.
QT离散度的测量是否能提供有关缺血心肌的存在及范围的信息存在争议。本研究旨在分析与铊-201单光子发射计算机断层扫描（Tl-201-SPECT）相比，QT离散度对检测心肌缺血的诊断价值。
从接受Tl-201-SPECT检查的患者中随机选取100例。在静息心电图的所有12个导联以及最大量自行车运动或双嘧达莫负荷高峰时的心电图中测量QT间期。计算所有患者以及分别按自行车运动组和双嘧达莫组的QT离散度，并将其与缺血参数进行相关性分析。
25例患者因无法测量QT离散度而被排除在分析之外。回归分析显示，对于所有75例患者、自行车运动组或双嘧达莫组，静息或负荷心电图中的QT离散度（QTd）与心肌缺血程度、缺血节段数及总缺血负荷评分均无显著相关性，且组间无显著差异。
100例患者中有25例（25%）无法测量QT离散度。在其余患者中，QT离散度与心肌缺血的范围或程度无关。
