Effectiveness of adaptive filtering in cancelling the respiratory component from cardiovascular series

Spectral analysis of cardiovascular variability signals is currently used as a tool for investigating autonomic neural control of heart activity and vasomotion. However, in many different pathophysiological conditions variations in tidal volume and/or respiratory rate may account for a possible respiratory parasympathetic contribution to low frequency variability of heart rate and blood pressure, currently interpreted as associated with sympathetic modulation. By cancelling respiratory contribution, adaptive filtering allows a better estimation of the purely vasomotor LF component of cardiovascular variability.