健康人24小时QT离散度动态变化

The dynamic change of QT interval dispersion during 24 hours in 30 healthy subjects

目的 探究健康人昼夜 2 4小时的 QT间期系列参数动态变化及其与心率变异性关系。方法 采用动态心电图监测技术 ,对 30例健康人 2 4小时动态心电图 QT间期系列参数 ,QTe、QTp、QTc、QTed、QTpd、QTcd,心率和心率变异性的频谱进行同步分析。将 QT系列参数与 HRV参数作直线相关分析。结果 在夜间高频 (HF)、RR间期增大时QTe、QTp延长 ,在白天 L F/ HF增高时 QTe、QTp缩短。QTc昼夜变化小。QTed、QTpd、QTc、QTcd在早晨清醒后第一或第二小时均出现第一个峰值 ,午睡清醒后第一小时也出现一个高峰值。而 HF及 L F/ HF无类似改变。结论 健康人昼夜2 4小时的 QT离散度变化与机体生理状态有关 ,这种变化主要接受不仅仅依赖心率和自主神经的调控 ,还受体液因素的调控。

Objective To investigate the dynamic change of QT interval dispersion during 24 hours and its correlation with heart rate variability in healthy subjects.Methods [WT5”BZ]The changes of QT interval and heart rate variability were recorded and analyzed simultaneously by 24-hour Holter recording in 30 healthy subjects.The QT interval to the end (QTe) and the peak(QTp) of T wave each hour were measured.The corrected QT interval (QTc) was calculated by Bazetts formula.The QTe,QTp and QTc dispersion was defined as the difference between the maximum and minimum values in each hour and any two leads.Spectral analysis of HRV yielded low frequency power(LF)(0.04～.15Hz),high frequency power(HF)(0.15～0.4Hz),and the ratio of LF to HF(LF/HF).Results The QTe and QTp prolonged while HF R R enhanced or heart rate decreased in the night,whereas they shortened when LF/HF increased during the day.The QTc had a small change during day and night,QTed and QTpd and QTc and QTcd had two peakvalues,and were displayed at the first or second hour after awakening in the morning and at noon.Conclusion The change of QT interval dispersion during 24 hours in healthy subjects,which is related to the physiologic behaviour,is modulated by autonomic nervous system,heart rate,and humoral factors.