运动锻炼对冠状动脉旁路移植术患者心率变异性的影响

目的：探讨运动锻炼对冠状动脉旁路移植术（CABG）后心脏自主神经功能的影响及其临床意义。方法：53例冠心病CABG患者被随机分为常规治疗组（25例）和康复组（28例，在常规治疗基础上进行运动锻炼），应用动态心电图心率变异性（HRV）时域指标：平均正常R—R间期的标准差（SDNN）、每5min正常R—R间期平均值的标准差（SDANN）、正常相邻R-R间期差的均方根（rMSSD）、相邻正常R-R间期内差值〉50ms的心搏数占总R-R间期总搏数的百分比（PNN50），分析术前、术后第2周及第8周自主神经功能指标的变化。结果：两组CABG术后2周SDNN、SDANN、rMSSD及PNN50较术前明显减低（P（0．05～0．01）；CABG术后8周，常规治疗组上述指标基本恢复到术前水平[SDNN（113．6±29．4）比（116．7±24．7），SDANN（112．2±32．1）比（113．6±28．6），rMSSD（21．9±8．2）比（23．2±7．1），andPNN50（7．5±4．2）比（8．2±3．7）]，P均〉0．05；康复组SDNN[（114．7±25．2）ms比（132．6±30．6）ms]、SDANN[（111．6±23．5）ms比（129．2±30．8）ms]、rMSSD[（24．2±8．7）ms比（29．9±7．5）ms]及PNN50[（7．8±2．2）ms比（9．5±2．3）ms]均较术前明显改善（P均〈0．05），且均显著优于常规治疗组[SDNN（132．6±30．6）比（113．6±29．4），SDANN（129．2±30．8）比（112．2±32．1），rMSSD（29．9±7．5）比（21．9±8．2）andPNN50（9．5±2．3）比（7．5±4．2）]，P均〈O．05。结论：CABG后2周心率变异性各项指标均减少，提示CABG对心脏自主神经系统有一定的损害。术后8周康复组心率变异性各项指标均显著优于常规治疗组，提示运动锻炼可较常规治疗显著改善CABG术后心脏自主神经功能。

Influence of exercise on heart rate variability in patients undergoing coronary artery bypass grafting

Objective： To explore influence of exercise on cardiac autonomic nerve function in patients undergoing coronary artery bypass grafting （CABG） and its clinical significance. Methods.. A total of 53 patients with coronary heart disease undergoing CABG were randomly divided into routine treatment group （n = 25） and rehabilitation group （n= 28, received exercise training based on routine treatment）. Changes of autonomic nerve function before, second and eighth week after CABG were analyzed in two groups using time domain indexes of heart rate variability （HRV） by ambulatory electrocardiography, including standard deviation of normal to normal RR intervals calculat- ed over the 24 h period （SDNN）, standard deviation of normal to normal RR intervals in all 5 min segments of the entire recording （SDANN）, root-mean square of differences between successive normal to normal intervals （rMSSD） and adjacent normal RR interval difference 〉 50ms stroke accounted for a percentage of 24h total RR interval （PNN50）. Results： Compared with before CABG, there were significant decrease in SDNN, SDANN, RMSSD and PNN50 in both groups two weeks after CABG （P〈0.05-0.01）; eight weeks after CABG, above indexes recovered to levels before CABG in routine treatment group ESDNN （113.6±29.4） vs. （116.7 d±24.7）, SDANN （112.2 ±32.1） vs. （113.6±28.6）, rMSSD （21.9±8.2） vs. （23.2±7.1）, and PNN50 （7.5±4.2） vs. （8.2±3.7）], P〉0.05 all; Compared with before CABG, there were significant improvements in SDNN [ （114.7± 25.2） ms vs. （132.6±30.6） ms], SDANN[ （111.6±23.5） ms vs. （129.2±30.8） ms], rMSSD[ （24.2±8.7） ms vs. （29.9± 7.5） ms] and PNN50 [ （7.8±2.2） ms vs. （9.5±2.3） ms], and there were significant improvement than those of routine treatment group ±SDNN （132.6±30.6） vs. （113. 6±29.4）, SDANN （129. 2±30. 8） vs. （112. 2±32.1）, rMSSD （29.9±7.5） vs. （21.9±8.2） and PNN50 （9.5±2.3） vs. （7.5±4.2）] eight weeks after CABG in reha- bilitation group, P〈0. 05 all. Conclusion： All HRV indexes significantly decrease on two weeks after CABG in both groups, suggesting that CABG can damage cardiac autonomic nerve system. These indexes of rehabilitation group were more improvement than those of routine treatment group, suggesting exercise training can more significantly improve cardiac autonomic nerve function after CABG.