Analysis of heart rate variability in patientswith congestive heart failure

To study the variance rules and the mechanism of pathophysiology ofheart rate variability (HRV) in patients with congestive heart failure (CHF), in thepresent study HRV was assessed in 92 patients with CHF and 51 normal subjects as con-trols. HRV was analysed with a Holter analysis system, in the time domain and fre-quency domain. The concentration of catecholamines in plasma and HRV have been fol-lowed up in some patients. It was found that: (1) HRV of nomal subjects and CHFgroup had a definite circadian variation. The HRV was higher in night than day time.(2) HRV was significantly lower in the CHF group than in controls and definite relatedto NYHAFC in the CHF group. (3) HRV of the deaths in the near future of CHF groupdecreased more significantly. (4)The concentrations of NE and E were greatly higher inCHF group than control group. Therefore, HRV of patients with CHF is significantlydiminished comparing with normal subjects. These reasults suggest that both vagal toneand sympathetic activition of heart are impaired. The changes of HRV in patients withCHF correspond to the severity of the clinical condition. High concentration of adrenlinecan indirectly explain that the impairment of autonomic nervous activity in heart is theresult of the sustained activation of endogenous neurohoronal systems.