老年人心肌梗死后心率变异性随访观察

Long- term effects of heart rate variability in elderly patients with myocardial infarction Tang Haiqin

为了解老年人急性心肌梗塞(AMI)后心率变异(HRV)的变化,对14例AMI后患者行动态心电图检查HRV时域五项指标,与正常对照组对比,并随访1—2年。结果患者的正常R—R间期标准差(SDNN)、平均值的标准差(SDANN)和标准差的平均值(SDNNIndex)低于对照组(P<0.01),而相邻正常R—R间期差值的平方根(RMSSD)和相邻正常R—R间期差值大于50ms次数占总R—R间期数的百分比(PNN_(50))降低不显著(P>0.05),随访1—2年HRV无显著改变,本组患者的心脏性猝死率为14.4％。老年人AMI后HRV降低,是由交感和迷走神经张力变化不平衡所致,HRV随访未恢复正常提示有心脏性猝死危险性。

Objective; To study the long-term offects of heart rate variability(HRV) in elderly patients after acute myocardial infarction ( AMI) Methods 14 elderly patients after AMI were examined with 24 hour ambulatory elec trocardiagraphic recordings to get five time domain measures of HRV, comparing of the healthy elderly group and follow up 1 - 2 years. Resultes 1 , Values of standard deviation of all RRintervals ( SDNN) , standard deviation of the averages of RR intervals in all 5-minute segments of the entire recording(SDANN) and mean of the standard deviations of all RR intervals for 5-minute segments of the entire recording (SDNN Index) in elderly patients with AMI were lower than those of contrary group(P<0. 01) , but values of the square root of the mean of the sun of the squares of differences between adjacent RR intervals(RMSSD)and NN50 count divided by the total number of all RR inter vals ( PNN50) were no significantly difference between two groups ( P> 0.05) 2, There were no singinifcan t changes of HRV in elderly patients during follow up 3 years. Rate of sudden cardial death was 14. 4 % in all elderly patients. Conclusion The elderly patient with myocardial infarction had lower value of HRV becaurse of unbalance between sympathetic and parasympathetic activity. There is risk of sudden cardial death in elderly patients with myocardial infarction while HRV not return to normal value in follow up.