The study of heart rate variability in patients with essential hypertension

Objective To study the characteristics of heart rate variability(HRV) in the patients with essential hypertension(EH) and autonomic neuropathy(ANP)and to evaluate the diagnostic value of HRV in EH patients with ANP.Methods 50 EH patients were divided into two groups:26 of grade-l group, 24 of grade-2 group, and 36 age-and sex-matched normal people were chosen as the controls. HRV and cardiovascular reflex tests(CVR) were performed in all people. In addition, the points of NN Intervals were achieved.Results The overall frequency of ANP in EH patients respectively was 48.00% by HRV and 26.00% by CVR (P0.05). Compared with the control,the HRV idexes of time domain and frequency domain significantly decreased in EH groups(P0.05), which in grade-2 EH group were significantly decreased than those in grade-1 EH group(P0.05). As the patterns of NN Interval plots were concerned, the proportion of comet-shaped pattern plots in EH groups significantly decreased while the proportion of torpedo-shaped pattern plots increased. There was a strong relationship between HRV and CVR.Conclusion HRV can be used as a sensitive method to diagnosis ANP in EH patients of early state and vagal neuropathy is the majority of the ANP in old EH patients.