Sympathetic activity and anxiety in hypertensive and normotensive subjects

Summary iological studies have shown that chronic anxiety is associated with a higher risk for sudden death through sympathetic hyperactivity. We studied the autonomic nervous system activity by spectral analysis of heart rate and blood pressure variability at rest in 33 normotensive and in 31 hypertensive subjects with anxiety symptoms. Power spectral analysis recognizes two main components: low frequency (LF), reflecting mainly sympathetic activity, and high frequency (HF), reflecting mainly vagal efferent activity. The ratio of low to high frequency powers (LF/HF) of heart rate variability provides a measure of sympathovagal balance. Power spectral analysis showed that the anxiety correlated positively with resting LF/HF ratio but correlated inversely with aging. In conclusion, we demonstrated an evidence for the prevalence of sympathetic indexes in subjects with anxiety symptoms. These are valuable markers of higher risk for sudden death and so, our opinion is that there is a natural selection with aging.