Heart rate variability and its changes over 5 years in older adults

PURPOSE: to characterise the association between age, ageing and heart rate variability (HRV) in older individuals, 585 adults age >65 years with two 24-h Holter recordings in the Cardiovascular Health Study were studied. METHODS: heart rate (HR), ventricular premature contractions (VPCs), atrial premature contractions (APCs), frequency-domain, ratio-based and non-linear HRV and heart rate turbulence (HRT) were examined cross-sectionally by 5-year age groups and prospectively over 5 years. Analyses adjusted for gender, lower versus elevated cardiovascular (CV) risk and for the change in CV risk. RESULTS: HR declined, and VPCs and APCs increased per 5-year increase in age. Frequency-domain HRV decreased more at 65-69, less at 70-74 and minimally at > or =75 years, independent of CVD risk or change in CVD risk. Ratio and non-linear HRV continued to decline to > or =75 years old. Ratio HRV and HRT slope were more strongly related to CVD risk than frequency-domain HRV. CONCLUSIONS: cardiac autonomic function, assessed by frequency-domain HRV, declines most at 65-70 and levels off at age >75. The decline is independent of CVD risk or change in CVD risk. Ratio-based and non-linear HRV and HRT slope continued to change with increasing age and were more closely related to CVD risk than frequency-domain HRV.