心率变异性与24h心肌缺血总负荷关系的研究

Correlation between heart rate variability and total myocardial ischemia burden in 24h

目的探讨心率变异性与心肌缺血总负荷之间的关系。方法分析106例心率变异性降低患者24h动态心电图,按心肌缺血总负荷中位数分为两组:轻度缺血组(53例)和重度缺血组(53例),比较两组之间冠状动脉粥样硬化性心脏病(冠心病)的冠状动脉造影及超声心动图结果;比较心率变异性指标,即一定时间内相邻两个正常心动周期差值>50ms的个数所占百分比(PNN50),24h内每5min节段平均正常心动周期的标准差(SDANN),24h内全部正常心动周期的标准差(SDNN),和心率变异性三角指数(HRVTI)。结果重度缺血组诊断冠心病及心肌肥厚的阳性率显著高于轻度缺血组;代表总功率SDNN和HRVTI及心率变异性高频成分的PNN50重度缺血组较轻度缺血组降低更为明显(P<0.01),而代表超低频成分的SDANN两组比较无统计学意义。结论心率变异性下降与心肌缺血总负荷程度呈正相关,尤其高频心率变异性指标与心肌缺血的相关性更好。

Objective To study the correlation between heart rate variability（HRV） and total myocardial ischemia burden（TIB）. Methods Electrocardiograms of the 106 patients with a low HRV in 24h were analyzed. The patients were divided into mild ischemia group（n=53） and sever ischemia group（n=53） according to their medium TIB. Results of coronary angiography（CAG） and ultrasonic cardiogram（UCG） of patients with coronary heart disease（CHD） were compared between two groups. HRV indexes including PNN50, SDNN, SDNN and HRVTI were also compared. Results The positive diagnostic rates of CHD and hypertension were higher in severe ischemia group than in mild ischemia group（P〈0.05）. The SDNN, HRVTI and PNN50 were also significantly higher in severe ischemia group than in mild ischemia group（P〈0.05）, while no significant difference was found in SDANN between the two groups. Conclusion Low HRV is positively correlated with the TMIB, and high HRV index is much more positively correlated with myocardial ischemia.