急性心肌梗死后患者心脏自主神经功能的动态变化研究

目的:观察急性心肌梗死患者(Acute myocardial infarction,AMI)发病10 d内、3月时自主神经功能(窦性心率震荡和心率变异性)的动态变化,冠脉血运重建治疗对自主神经功能恢复的影响,以及淋巴细胞Gαi-2蛋白表达的变化与自主神经功能恢复的相关性.方法:对入选的64例无严重并发症的AMI患者根据冠脉血运重建情况分为血运重建组和非血运重建组,分别在发病10d内(6～10 d),3月时两个时间段作心率,变异(Heart rate variability,HRV)和窦性心率震荡(Heart rate turbulence,HRT)分析,并检测患者淋巴细胞Gαi-2蛋白表达.结果:非血运重建组患者AMI 10 d内HRT指标震荡初始(Turbulence onset,T0)和震荡斜率(Turbulence slop,TS),HRV指标高功率谱(High-frequency power,HF)/总功率谱(Total-frequency power,TF)和SDNN均降低,AMI后3月这些指标均比10 d时有显著改善(P<0.05);血运重建组患者AMI 10 d内TS明显恢复,AMI后3月TO、HF/TF、SDNN值才有明显恢复.以SDNN>100 ms、TO2.5 ms/RR为正常参考值进行比较,两组在AMI 10 d内只有TS>2.5ms/RR有显著差异(P=0.024),AMI后3月这3个指标在两组间均无显著差异.AMI后不同时间内淋巴细胞Gαi-2蛋白表达的变化仅与SDNN的变化呈中等程度的正相关(r=0.448,P=O.017),与TS、TO、HF/TF等无相天性.结论:AMI后患者HRT和HRV均有动态变化现象,成功的冠脉血运重建治疗可以使反应压力感受器敏感性的HRT很快恢复,但对HRV无明显影响.Gαi-2蛋白表达与心脏迷走神经变化的相关性有待进一步研究证实.

Changes of cardiac autonomic nervous function after acute myocardial infarction

Objective: To assess the changes of cardiac autonomic nervous function at 10 days and 3 months in patients after acute myocardial infarction (AMI) by heart rate variability (HRV) and heart rate turbulence (HRT).In parallel, we examined whether the changes in cardiac autonomic nervous function correlated with coronary revascularization and the expression of G alpha]i2. Methods :64 postinfarction patients without severe complications were enrolled. According to whether successful reperfusion was received, they were divided into two groups (coronary revascularization group and non-coronary revascularization group). 24-hour,three-lead ambulatory electrocardiography were performed in all subjects for the analysis of HRV (SDNN and HF/TF) and HRT(TO and TS) at 10 days and three months after acute myocardial infarction.The expression of Galpha]i2 was assessed by Western blot analysis of lymphocytes from patients at the two time points. Results:The fraction of HF/TF and SDNN increased and TO decreased at the time point of three months after AMI in both two groups compared to the time point of 10 days after AMI.TS also increased in non-coronary revascularization group but there was no significant difference between the two time points in coronary revascularization group. There were no significant differences in the parameters (SDNN>100 ms,TO<0,TS>2.5 ms/RR) at 3 months after AMI between two groups. At 10 days after AMI, there was a significant difference in TS between two groups, but there was no significant difference in the SDNN>100 ms and the TO<0. The changes of the Galpha]i2 protein expression were only associated with the changes of SDNN(r= 0.448,P=0.017). Conclusion: There are dynamic changes of HRT and HRV in patients after AMI. The improvement of HRT after successful reperfusion might reflect rapid restoration of baroreceptor sensitivity, but there is no impact on HRV. The hypothesis that G alpha]i2 could serve as molecular marker of cardiac vagal efferent activity could not be supported by the study .