Heart Rate Variability in the Elderly with Myocardial Infarction

Objective:To investigate the heart rate variability (HRV) of the elderly with myocardial infarction during one-year period following the onset of the disease and to understand the regulation of cardiac vegetative nerves after myocardial infarction.Methods:Time domain method was applied to measure five indexes of HRV in 50 old patients with myocardial infarction during the first year after the disease on our follow-up program at the out-patient department.50 normal elderly without evidence of coronary artery disease were treated as control.Results: SDNN,SDANN and SDNNindex in the myocardial infarction group were much lower than those in control group (P0.01);RMSSD,PNN50 of the myocardial infarction group were also reduced (P0.05).Conclusions:HRV of the elderly with myocardial infarction still changes abnormaly during one-year period after the onset of the disease,indicating vegetative nerves dysfunction and predicting a increasing rate of serious arrhythmia and sudden cardiac death.