Abstract Background : the transition to microgravity eliminates the hydrostatic gradients in the vascular system. The resulting fluid redistribution commonly manifests as facial edema, engorgement of the external neck veins, nasal congestion, and headache. This experiment examined the responses to modified Valsalva and Mueller maneuvers measured by cardiac and vascular ultrasound (ECHO) in a baseline steady state and under the influence of thigh occlusion cuffs available as a countermeasure device (Braslet cuffs). Methods : nine International Space Station crewmember subjects (expeditions 16–20) were examined in 15 experiment sessions 101 ± 46 days after launch (mean ± SD; 33–185). Twenty-seven cardiac and vascular parameters were obtained with/without respiratory maneuvers before and after tightening of the Braslet cuffs (162 parameter states/session). Quality of cardiac and vascular ultrasound examinations was assured through remote monitoring and guidance by investigators from the NASA Telescience Center in Houston, TX, and the Mission Control Center in Korolyov, Moscow region, Russia. Results : 14 of 81 conditions (27 parameters measured at baseline, Valsalva, and Mueller maneuver) were significantly different when the Braslet was applied. Seven of 27 parameters were found to respond differently to respiratory maneuvers depending on the presence or absence of thigh compression. Conclusions : acute application of Braslet occlusion cuffs causes lower extremity fluid sequestration and exerts commensurate measurable effects on cardiac performance in microgravity. Ultrasound techniques to measure the hemodynamic effects of thigh cuffs in combination with respiratory maneuvers may serve as an effective tool in determining the volume status of a cardiac or hemodynamically compromised patient at the “microgravity bedside.” microgravity echocardiography astronaut occlusion cuffs cardiac function Copyright © 2012 the American Physiological Society « Previous | Next Article » Table of Contents This Article Published online before print September 2011 , doi: 10.​1152/​japplphysiol.​00557.​2011 Journal of Applied Physiology February 2012 vol. 112 no. 3 454-462 » Abstract Free Full Text Free to you Full Text (PDF) Free to you All Versions of this Article: japplphysiol.00557.2011v1 112/3/454 most recent Classifications Article Services Email this article to a friend Alert me when this article is cited Alert me if a correction is posted Alert me when eletters are published Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Download to citation manager Responses Submit a response No responses published Citing Articles Load citing article information Citing articles via Web of Science Google Scholar Articles by Hamilton, D. R. Articles by Duncan, J. M. PubMed PubMed citation Articles by Hamilton, D. R. Articles by Duncan, J. M. Related Content Load related web page information Current Issue February 2012, 112 (3) Alert me to new issues of Journal of Applied Physiology About the Journal Information for Authors Submit a Manuscript Ethical Policies AuthorChoice PubMed Central Policy Reprints and Permissions Advertising Press Copyright © 2012 the American Physiological Society Print ISSN: 8750-7587 Online ISSN: 1522-1601 var gaJsHost = (("https:" == document.location.protocol) ? "https://ssl." : "http://www."); document.write(unescape("%3Cscript src='" + gaJsHost + "google-analytics.com/ga.js' type='text/javascript'%3E%3C/script%3E")); var pageTracker = _gat._getTracker("UA-2924550-1"); pageTracker._trackPageview();

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