Voluntary control of breathing showed heart rate increased during inspiration (delay ~0.9 s) and systolic blood pressure decreased (phase delay ~160°), independent of simple heart rate changes.
Observational
How does voluntary control of breathing pattern affect blood pressure and heart rate oscillations in healthy subjects?
Respiratory effects on systolic blood pressure are likely caused by mechanisms other than simply changes in heart rate.
SUMMARY 1. The relationships of respiratory sinus arrhythmia (RS A) and respiratory changes in systolic blood pressure (SBP) to tidal volume ( V T ) and breathing frequency (BF), were quantified during voluntary control of V T and BF in healthy subjects. 2. Respiration was measured non‐invasively with a respiratory inductive plethysmograph, which was calibrated prior to each study while breathing through a pneumotachygraph. Finger arterial blood pressure was measured non‐invasively by the Finapres. 3. Heart rate (HR) increased during inspiration, with a nearly fixed time delay for most V T and BF approximating 0.9 s. The magnitude of RS A increased with increases in V T and with decreases in BF. SBP decreased during inspiration, with a time delay which increased as BF decreased, resulting in a phase delay approximating 160°. The magnitude of the inspiratory fall in SBP increased with increases in V T . Increased amplitudes of RSA and SBP variation occurred at the lowest BF, consistent with the possibility of interactions between respiratory‐related influences and those due to ‘slow waves’ of vasomotor tone. 4. The present results are consistent with the conclusion that respiratory effects on SBP are caused by a mechanism other that simply changes in HR.
Laude et al. (Fri,) conducted a observational in Healthy subjects. Voluntary control of tidal volume and breathing frequency was evaluated on Relationships of respiratory sinus arrhythmia and systolic blood pressure changes to tidal volume and breathing frequency. Voluntary control of breathing showed heart rate increased during inspiration (delay ~0.9 s) and systolic blood pressure decreased (phase delay ~160°), independent of simple heart rate changes.