Document Detail


Effects of repeated Valsalva maneuver straining on cardiac and vasoconstrictive baroreflex responses.
MedLine Citation:
PMID:  12650267     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
INTRODUCTION: We hypothesized that repeated respiratory straining maneuvers (repeated SM) designed to elevate arterial BPs (arterial baroreceptor loading) would acutely increase baroreflex responses. METHODS: We tested this hypothesis by measuring cardiac baroreflex responses to carotid baroreceptor stimulation (neck pressures), and changes in heart rate and diastolic BP after reductions in BP induced by a 15-s Valsalva maneuver in 10 female and 10 male subjects at 1, 3, 6, and 24 h after performing repeated SM. Baroreflex responses were also measured in each subject at 1, 3, 6, and 24 h at the same time on a separate day without repeated SM (control) in a randomized, counter-balanced cross-over experimental design. RESULTS: There was no statistical difference in carotid-cardiac and peripheral vascular baroreflex responses measured across time following repeated SM compared with the control condition. Integrated cardiac baroreflex response (deltaHR/ deltaSBP) measured during performance of a Valsalva maneuver was increased by approximately 50% to 1.1 +/- 0.2 bpm x mm Hg(-1) at 1 h and 1.0 +/- 0.1 bpm x mm Hg(-1) at 3 h following repeated SM compared with the control condition (0.7 +/- 0.1 bpm x mm Hg(-1) at both 1 and 3 h, respectively). However, integrated cardiac baroreflex response after repeated SM returned to control levels at 6 and 24 h after training. These responses did not differ between men and women. CONCLUSIONS: Our results are consistent with the notion that arterial baroreceptor loading induced by repeated SM increased aortic, but not carotid, cardiac baroreflex responses for as long as 3 h after repeated SM. We conclude that repeated SM increases cardiac baroreflex responsiveness which may provide patients, astronauts, and high-performance aircraft pilots with protection from development of orthostatic hypotension.
Authors:
Victor A Convertino; Duane A Ratliff; Donald F Doerr; David A Ludwig; Gary W Muniz; Erik Benedetti; Jose Chavarria; Susan Koreen; Claude Nguyen; Jeff Wang
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Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, Non-P.H.S.    
Journal Detail:
Title:  Aviation, space, and environmental medicine     Volume:  74     ISSN:  0095-6562     ISO Abbreviation:  Aviat Space Environ Med     Publication Date:  2003 Mar 
Date Detail:
Created Date:  2003-03-24     Completed Date:  2003-06-09     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  7501714     Medline TA:  Aviat Space Environ Med     Country:  United States    
Other Details:
Languages:  eng     Pagination:  212-9     Citation Subset:  IM; S    
Affiliation:
U.S. Army Institute of Surgical Research, Ft. Sam Houston, TX 78234-6315, USA. victor.convertino@cen.amedd.army.mil
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MeSH Terms
Descriptor/Qualifier:
Adult
Aerospace Medicine
Baroreflex / physiology*
Blood Pressure
Female
Heart Rate
Humans
Hypotension, Orthostatic / prevention & control
Male
Pressoreceptors / physiology
Space Flight
Valsalva Maneuver*
Investigator
Investigator/Affiliation:
V A Convertino / Inst Surg Res, Ft Sam Houston, TX
Comments/Corrections
Erratum In:
Aviat Space Environ Med. 2003 May;74(5):586

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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