健康人不同导联QT变异及QT变异指数

QT Interval Variability and QT Variability Index Among Different Leads in Healthy Subjects

探讨健康人不同导联的QT变异(QTV)及QT变异指数(QTVI)。55例健康人在保持日常工作和生活起居的情况下佩戴12导联动态心电图监测仪,计算机辅助下自动测量12导联QT间期,计算每个导联每小时、24h、白天(6:00～22:00)和夜间(22:00～6:00)QT间期均值及其标准差、HR间期均值及其标准差,它们分别代表相应时间段的QT间期均值(QTm)、QTV、HR间期均值(HRm)和HR间期变异(HRV)。计算QTVI。同时运用心率变异时域指标SDNN观察自主神经活性。结果:不同导联间的QTV、QTVI比较具有显著性差异,P<0.05。不同导联24hQTV、QTVI与SDNN均存在负相关,P<0.05。结论:在使用QTV、QTVI来评价不同人群的心室复极离散时,要考虑到不同导联之间的可比性和一致性。QTVI是一种能更直接地反映心室复极逐波变化的新指标。

To study QT interval variability（QTV） and QT variability index （QTVI） among different leads in healthy subjects ,55 healthy subjects underwent 24 hours Hoher monitoring in normal life style . The mean of QT intervals（ QTm）, the standard deviation of QT intervals（ QTV）, the mean of HR intervals（ HRm）, the standard deviation of HR intervals（HRV） and QTVI were calculated for every hour during the day and the night, while SDNN was analyzed simultaneously by computer during 24 hours as heart rate variability. Results： There was a significant difference in QTV and QTVI among different leads. QTV and QTVI had a negative correlation with SDNN in different leads in healthy subjects. Conclusions ： The beat-to-beat ventricular repolarization heterogeneity has a regional characteristic, so this finding should be evaluated in relation to the issue of local versus global cardiac repolarization of ventricular myocardium when QTV and QTVI is calculated. QTVI may provide a new nonvasive tool to evaluate the beat-to-beat ventricular repolarization heterogeneity .