Age-adjusted heart rate variability as an index of the severity and prognosis of heart failure

The age-adjusted, heart rate variability (HRV) was evaluated as a parameter for the severity of heart failure and its prognosis. HRV was obtained by 2 4-h Holter monitoring in patients with left ventricular dysfunction (LVD). New York Heart Association (NYHA) functional classification, echocardiograp hy, radioisotope ventriculography, and blood examination were performed, an d compared between patients and normal subjects. The evaluation was repeate d during the follow-up period. Finally, using the lower limit of HRV, patie nts were divided into either normal or abnormal group for each low-frequenc y power (LF) and high-frequency power (HF) (age-adjusted HRV). Other parame ters of heart failure and prognosis were compared between these 2 groups. H RV tended to be lower in patients with LVD. HF decreased at the early stage of heart failure, but did not decrease progressively. LF decreased progres sively. HRV change paralleled the change of NYHA. The abnormal HRV group sh owed a poor prognosis for cardiac death, but not for sudden cardiac death. in patients with LVD, HRV was decreased compared with the normal subjects. Change in HRV correlated with the change in NYHA classification. Age-adjust ed HRV correlated with cardiac-death prognosis, but not for sudden cardiac death.