心肌缺血与QT与QTc间期的动态变化

Ischemia and QT or QTc interval dynamicity

目的观察ＱＴ和ＱＴｃ与心肌缺血和自主神经状态之间的关系。方法５２例动态心电图中见发作性ＳＴ段下移的病例被列为分析病例，男３７例，女１５例，平均年龄６０±１０（４１～８２）岁。结果显示ＳＴ段下移前和最大下移时，ＱＴ和心率的ＲＲ间期均有相关性（ｒ均＝０．７５，Ｐ＜０．０１），但ＱＴ与ＲＲ间期直线回归方程的截距有显著性差异（ｔ检验，Ｐ＜０．０５）；ＳＴ段下移前５分钟和ＳＴ段最大下移时，ＱＴｃ和心率有显著性差异，ＱＴｃ的差值与心率（ｒ＝０．３４，Ｐ＜０．０５）和最大ＳＴ段下移的程度（ｒ＝０．３１，Ｐ＜０．０５）呈正相关。结论心肌缺血是影响ＱＴ和ＱＴｃ的主要因素。

Objective The aim of this investigation is to study the relationships between QT or QTc and ischemia or autonomic nervous system condition.Methods 52 patients with episodic ST depression in ambulatory ECG were included,37 men and 15 women,mean age was 60±10 years (41～82).Results The data showed the QT and RR interval had significant correlation ( r=0 75,P <0 01)both before the ST depression and during the maximal ST depression,but the intercepts of QT/RR regression lines had significant difference ( P <0 05)。Both heart rate and QTc at the 5 minutes before the ST depression was different significantly from those at the maximal ST depression,and the difference of QTc was correlated to the heart rate ( r=0 34,P <0 05) and the level of the ST depression ( r =0 31, P <0 05).Conclusion The results suggested that the ischemia was the major factor which influenced the QT and QTc.