The effect of breathing maneuvers on theinteraction between pulse fluctuation and heartrate variability

Abstract

Respiration has appeared as a useful knob to turn up and down the autonomic nervous system (ANS). In particular, several studies have reported plenty of benefits on emotional and physiological health from slow paced breathing, even though little is known about paced breathing at normal or even fast rates. In this work, we have systematically investigated the physiological interactions between the blood volume pressure signal (Bvp) and the heart rate (HR) during spontaneous and paced breathing at normal (NB), fast (FB) and slow (SB) rates. Such interactions were quantified by the cross-amplitude spectrum, by detecting peak amplitude and peak frequency at every phase. The spontaneous phase presented no structured interaction, while the SB showed, as expected, clearly defined peaks at the breathing frequency (at about 0.1 Hz). The NB phase presented peaks at both, under and above 0.1 Hz, revealing energy at both sympatho-vagal bands. The FB phase showed a vagal withdrawal, with peaks located at about 0.05 Hz; very similar to those interactions arisen during the stressor test, which consisted of the N-Back test (cognitive load). In conclusion, the cross amplitude spectrum satisfactorily separated four different ANS scenarios, which might have potential for emotion recognition.