冠心病心率变异与心肌缺血的关系

Heart Rate Variability in Coronary Heart Disease and Its Association with Myocardial Ischemia

本文３５例冠心病人均做２４ｈ动态心电图检查，逐段记录２４ｈ缺血心电图ＳＴ段下移时间，观察心肌缺血与心率变异之间的关系。心率变异采用统计学方法计算２４ｈＲ－Ｒ间期标准差，１３的病人标准差小于５０ｍｓ为心率变异低组，２２例病人标准差大于５０ｍｓ为心率变异高组。心率变异低与心率变异高两组病人比较，心肌缺血发作年数和总缺血时间有显著性差异（Ｐ＜０．０１，Ｐ＜０．０５），总缺血时间与心率变异呈低度负相关（ｒ＝－０．２９，Ｐ＜０．０５）；两组病人非持续性室性心动过速比较亦有显著性差异（Ｐ＜０．０５）。说明心率变异低与心肌缺血有关，并易发生危险性心律失常。

To investigate the associtation of heart rate variability with myocardial ischemia we observed the 24 h dynamic electrocardiogram in 35 cases of coronary heart disease. Heart rate variability was obtained statistically by a measure of the standard deviation of the set of all R-R intervals in a 24 h period while myocardial ischemia was estimated by the total time of the myocardial ischemia attack recorded in the 24 h dynamic electrocardiogram. The 35 patients were divided into high and low standard deviation group (high group standard deviation>50 ms ,low standard deviation≤50ms). 22 patients were in high group and 13 patients were in low group. Comparison was made between the 2 groups in the number of transient myocardial ischemia attack and the total time of the myocardial ischemia in a 24 h period. The study showed significant differences existed between the 2 group both in numbers and in the total time of transient myocardial ischemic attack (P<0. 01,P<0.05). Negative correlation of low degree was observed between heart rate variability and total ischemic time (r=-0.29 , P<0. 05 ). Significant difference could also be seen between the 2 groups in the numbers of nonsustained ventricular tachycardia (P<0. 05). Our study indicated that low heart rate variability associated with myocardial ischemia and might be predisposed to serious arrhythmia.