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dc.contributor.authorEwalts, Michiel
dc.contributor.authorDawkins, Tony
dc.contributor.authorBoulet, Lindsey
dc.contributor.authorThijssen, Dick
dc.contributor.authorStembridge, Mike
dc.date.accessioned2021-01-05T11:51:42Z
dc.date.available2021-01-05T11:51:42Z
dc.date.issued2020-12-28
dc.identifier.citationEwalts, M., Dawkins, T., Boulet, L.M., Thijssen, D. and Stembridge, M. (2020) 'The influence of increased venous return on right ventricular dyssynchrony during acute and sustained hypoxemia', Experimental Physiology. https://doi.org/10.1113/EP088657en_US
dc.identifier.issn0958-0670
dc.identifier.issn1469-445X (electronic)
dc.identifier.urihttp://hdl.handle.net/10369/11254
dc.descriptionArticle published in Experimental Physiology available at https://doi.org/10.1113/EP088657en_US
dc.description.abstractRegional heterogeneity in timing of right ventricular (RV) contraction (RV dyssynchrony; RVD) occurs when pulmonary artery systolic pressure (PASP) is increased during acute hypoxia. Interestingly, RVD is not observed during exercise, a stimulus that increases both PASP and venous return. Therefore, we hypothesized that RVD in healthy humans is sensitive to changes in venous return, and examined whether (i) increasing venous return in acute hypoxia lowers RVD and (ii) if RVD is further exaggerated in sustained hypoxia, given increased PASP is accompanied by decreased ventricular filling at high altitude. RVD, PASP and RV end diastolic area (EDA) were assessed using transthoracic two‐dimensional and speckle‐tracking echocardiography during acute normobaric hypoxia (FiO2 = 0.12) and sustained exposure (5‐10 days) to hypobaric hypoxia (3800m). Venous return was augmented with lower body positive pressure at sea level (LBPP; +10 mmHg) and saline infusion at high altitude. PASP was increased in acute hypoxia (20±6 vs. 28±7, P<0.001) concomitant to an increase in RVD (18±7 vs. 38±10, P<0.001); however, the addition of LBPP during hypoxia decreased RVD (38±0 vs. 26±10, P<0.001). Sustained hypoxia increased PASP (20±4 vs. 26±5, P = 0.008) and decreased RV EDA (24±4 vs. 21±2, P = 0.042), with RVD augmented (14±5 vs. 31±12, P = 0.001). Saline infusion increased RV EDA (21±2 vs. 23 ± 3, P = 0.008) and reduced RVD (31±12 vs. 20±9, P = 0.001). In summary, an increase in PASP secondary to acute and sustained exposure to hypoxia augments RVD, which can be at least partly reduced via increased venous return.en_US
dc.language.isoenen_US
dc.publisherWileyen_US
dc.relation.ispartofseriesExperimental Physiology;
dc.titleThe influence of increased venous return on right ventricular dyssynchrony during acute and sustained hypoxemiaen_US
dc.typeArticleen_US
dc.identifier.doihttps://doi.org/10.1113/EP088657
dcterms.dateAccepted2020-12-19
rioxxterms.funderCardiff Metropolitan Universityen_US
rioxxterms.identifier.projectCardiff Metropolian (Internal)en_US
rioxxterms.versionAMen_US
rioxxterms.licenseref.urihttp://www.rioxx.net/licenses/all-rights-reserveden_US
rioxxterms.funder.project37baf166-7129-4cd4-b6a1-507454d1372een_US


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