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dc.contributor.authorStembridge, Mike
dc.contributor.authorAinslie, Philip N.
dc.contributor.authorBoulet, Lindsey M.
dc.contributor.authorAnholm, James
dc.contributor.authorSubedi, Prajan
dc.contributor.authorTymko, Michael M.
dc.contributor.authorWillie, Christopher K.
dc.contributor.authorCooper, Stephen-Mark
dc.contributor.authorShave, Rob
dc.date.accessioned2018-06-01T10:08:03Z
dc.date.available2018-06-01T10:08:03Z
dc.date.issued2018-05-28
dc.identifier.citationStembridge, M. , Ainslie, P. N., Boulet, L. M., Anholm, J. , Subedi, P. , Tymko, M. M., Willie, C. K., Cooper, S. and Shave, R. (2018) 'The independent effects of hypovolemia and pulmonary vasoconstriction on ventricular function and exercise capacity during acclimatisation to 3800 m', Journal of Physiology. Accepted Author Manuscript. doi:10.1113/JP275278en_US
dc.identifier.issn0022-3751
dc.identifier.issn1469-7793 (online)
dc.identifier.urihttp://hdl.handle.net/10369/9631
dc.descriptionArticle published in Journal of Physiology available at https://doi.org/10.1113/JP275278en_US
dc.description.abstractWe aimed to determine the isolated and combined contribution of hypovolemia and hypoxic pulmonary vasoconstriction in limiting left ventricular (LV) function and exercise capacity under chronic hypoxemia at high altitude. In a double‐blinded, randomized and placebo‐controlled design, twelve healthy participants underwent echocardiography at rest and during submaximal exercise before completing a maximal test to exhaustion at sea level (SL; 344 m) and after 5–10 days at 3800 m. Plasma volume was normalised to SL values, and hypoxic pulmonary vasoconstriction was reversed by administration of Sildenafil (50 mg) to create four unique experimental conditions that were compared with SL values; high altitude (HA), Plasma Volume Expansion (HA‐PVX), Sildenafil (HA‐SIL) and Plasma Volume Expansion with Sildenafil (HA‐PVX‐SIL). High altitude exposure reduced plasma volume by 11% (P < 0.01) and increased pulmonary artery systolic pressure (19.6 ± 4.3 vs. 26.0 ± 5.4, P < 0.001); these differences were abolished by PVX and SIL respectively. LV end‐diastolic volume (EDV) and stroke volume (SV) were decreased upon ascent to high altitude, but were comparable to sea level in the HA‐PVX. LV EDV and SV were also elevated in the HA‐SIL and HA‐PVX‐SIL trials compared to HA, but to a lesser extent. Neither PVX or SIL had a significant effect on the LV EDV and SV response to exercise, or the maximal oxygen consumption or peak power output. In summary, at 3800 m both hypovolemia and hypoxic pulmonary vasoconstriction contribute to the decrease in LV filling, however, restoring LV filling does not confer an improvement in maximal exercise performance.en_US
dc.description.sponsorshipGouvernement du Canada Natural Sciences and Engineering Research Philip N Ainslie, F09-05728 Canada Research Chair: Philip N Ainslie, F11-0243en_US
dc.language.isoenen_US
dc.publisherWileyen_US
dc.relation.ispartofseriesThe Journal of Physiology;
dc.subjecthypoxiaen_US
dc.subjecthigh altitudeen_US
dc.subjectcardiac functionen_US
dc.subjectleft ventricular mechanicsen_US
dc.subjecthypovolemiaen_US
dc.subjectpulmonary vasoconstrictionen_US
dc.subjectpulmonary hypertensionen_US
dc.subjectdiastolic functionen_US
dc.titleThe independent effects of hypovolemia and pulmonary vasoconstriction on ventricular function and exercise capacity during acclimatisation to 3800 men_US
dc.typeArticleen_US
dc.identifier.doihttps://doi.org/10.1113/JP275278
dcterms.dateAccepted2018-04-17
rioxxterms.funderCardiff Metropolitan Universityen_US
rioxxterms.identifier.projectCardiff Metropolian (Internal)en_US
rioxxterms.versionAMen_US
rioxxterms.licenseref.urihttp://www.rioxx.net/licenses/under-embargo-all-rights-reserveden_US
rioxxterms.licenseref.startdate2019-05-28
rioxxterms.freetoread.startdate2019-05-28
rioxxterms.funder.project37baf166-7129-4cd4-b6a1-507454d1372een_US


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