The pattern of sympathovagal balance explored in the frequency domain

In most physiological conditions, sympathetic and vagal activities modulati ng heart period undergo a reciprocal regulation, leading to the concept of sympathovagal balance. This pattern can be indirectly quantified by computi ng the spectral powers of the oscillatory components corresponding to respi ratory acts (high frequency) and to vasomotor waves (low frequency) present in heart rate variability.