Skip Navigation

Cardiovascular Research 1998 38(2):332-339; doi:10.1016/S0008-6363(98)00029-7
© 1998 by European Society of Cardiology
This Article
Right arrow Full Text Freely available
Right arrow FREE Full Text (PDF) Freely available
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Pitzalis, M. V.
Right arrow Articles by Rizzon, P.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Pitzalis, M. V.
Right arrow Articles by Rizzon, P.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

Copyright © 1998, European Society of Cardiology

Effect of respiratory rate on the relationships between RR interval and systolic blood pressure fluctuations: a frequency-dependent phenomenon

Maria Vittoria Pitzalisa,*, Filippo Mastropasquab, Francesco Massarib, Andrea Passantinob, Roberto Colomboc, Antonella Mannarinia, Cinzia Forleob and Paolo Rizzona

aInstitute of Cardiology, University of Bari, Piazza Giulio Cesare 11, 70124 Bari, Italy
bDepartment of Cardiology, ‘Salvatore Maugeri’ Foundation IRCCS, Cassano Medical Centre, Cassano (Ba) 70020, Italy
cBioengineering Service, ‘Salvatore Maugeri’ Foundation IRCCS, Veruno Medical Centre, Veruno, Italy

* Corresponding author. Tel.: +39 80 5478631; fax: +39 80 5478796; e-mail: pitzalis@mbox.vol.it

Objective: The aims of this study were to determine the relationships between oscillations in systolic blood pressure and heart period at different breathing frequencies and to investigate the role of sympathetic contribution to this relationship. Methods: Fourteen healthy volunteers underwent three randomized periods of controlled breathing at 6, 10 and 16 breaths/min. ECG (RR), respiratory signal (RESP) and systolic blood pressure (SBP) were continuously recorded. The component of RR and SBP oscillations related to respiration (RRResp and SBPResp) was defined by means of uni- and bivariate spectral analysis. The squared coherence (K2) and phase between RR and RESP, and RR and SBP (RR-SBP) were also assessed. When the K2 of RR-SBP in the respiratory band was >0.5, we considered the phase and calculated the closed-loop gain between the two signals. Seven subjects were also studied after chronic metoprolol treatment. Results: Although the mean values of RR and SBP did not differ between the three periods of breathing, the higher the respiratory rate, the smaller the RRResp and SBPResp. The phase was always negative (SBPResp changes preceded RRResp changes), thus suggesting a baroreflex link. The higher the respiratory rate, the lower the gain and phase. Pharmacological β-adrenoceptor blockade increased the gain and shifted the phase, but the relationships found at baseline between the respiratory rate and both the gain and phase remained unchanged. Conclusions: The effect of breath rate on the relationship between heart rate and systolic pressure variabilities is a frequency-dependent phenomenon that is also independent of the sympathetic drive.

KEYWORDS Heart rate variability; Respiratory sinus arrhythmia; Systolic blood pressure variability; Metoprolol; Baroreflex gain; Cardiorespiratory index; Bode plot


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer:
Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.