Abstract
The relationship of respiratory sinus arrhythmia (RSA) to the accompanying oscillations of cardiovascular pressure has been studied in five healthy subjects. Tidal volume (VT) of 1.0, 1.5, and 2.0 1 at the breathing rate of 6 c-min-1 were used as reference. With identical VT oesophageal pressure was varied by negative inspiratory pressure (NIP) and intermittent positive-pressure ventilation (IPPV). Compared with control, NIP with 1.01 significantly increased RSA, the oscillations of brachial artery pressures (PBA), and the net filling pressures of the ventricles. IPPV did not significantly change the variations of PBA but reduced RSA and the respiratory variations of the right ventricular end-diastolic net pressure. During control breathing and with NIP the acceleration of heart rate during inspiration was associated with rising PBA and rising net filling pressures of both ventricles. The results indicate that RSA may be elicited by cardiovascular reflexes due to changes in venous filling of the heart rather than by the variations in systemic arterial pressure.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Scandinavian Journal of Clinical and Laboratory Investigation
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
