Power Spectral Analysis of Spontaneous Blood Pressure and Heart Rate Variability in Elderly Hypertensives

To examine the influence of hypertension on cardiovascular variability in elderly subjects, we measured spontaneous beat-to-beat blood pressure (BPV) and heart rate variability (HRV) in elderly subjects with or without hypertension at rest and during tilting. The study group consisted of 23 community-dwelling, male elderly subjects (aged 62-75 years) and was divided into two groups, i.e., a hypertensive group (HT group; n=11) and normotensive group (NT group; n=12). According to the modeling and decomposing algorithm of an autoregressive process, we estimated the component power of low-frequency (LF; 0.03-0.15Hz) and high-frequency components (HF; respiratory frequency) of BPV and HRV by power spectral analysis. We also measured plasma norepinephrine (PNE) levels in the two groups at rest and during tilting. In the HT group, we found that the amplitude of LF-BPV was greater (p