Show simple item record

dc.contributor.authorCross, Troy J
dc.contributor.authorKavanagh, Justin J
dc.contributor.authorBreskovic, Toni
dc.contributor.authorMaslov, Petra Zubin
dc.contributor.authorLojpur, Mihajlo
dc.contributor.authorJohnson, Bruce D
dc.contributor.authorDujic, Zeljko
dc.date.accessioned2017-05-03T14:04:57Z
dc.date.available2017-05-03T14:04:57Z
dc.date.issued2013
dc.date.modified2014-01-23T22:37:10Z
dc.identifier.issn1932-6203
dc.identifier.doi10.1371/journal.pone.0066950
dc.identifier.urihttp://hdl.handle.net/10072/56044
dc.description.abstractThe effects of involuntary respiratory contractions on the cerebral blood flow response to maximal apnoea is presently unclear. We hypothesised that while respiratory contractions may augment left ventricular stroke volume, cardiac output and ultimately cerebral blood flow during the struggle phase, these contractions would simultaneously cause marked 'respiratory' variability in blood flow to the brain. Respiratory, cardiovascular and cerebrovascular parameters were measured in ten trained, male apnoea divers during maximal 'dry' breath holding. Intrathoracic pressure was estimated via oesophageal pressure. Left ventricular stroke volume, cardiac output and mean arterial pressure were monitored using finger photoplethysmography, and cerebral blood flow velocity was obtained using transcranial ultrasound. The increasingly negative inspiratory intrathoracic pressure swings of the struggle phase significantly influenced the rise in left ventricular stroke volume (R2 = 0.63, P<0.05), thereby contributing to the increase in cerebral blood flow velocity throughout this phase of apnoea. However, these contractions also caused marked respiratory variability in left ventricular stroke volume, cardiac output, mean arterial pressure and cerebral blood flow velocity during the struggle phase (R2 = 0.99, P<0.05). Interestingly, the magnitude of respiratory variability in cerebral blood flow velocity was inversely correlated with struggle phase duration (R2 = 0.71, P<0.05). This study confirms the hypothesis that, on the one hand, involuntary respiratory contractions facilitate cerebral haemodynamics during the struggle phase while, on the other, these contractions produce marked respiratory variability in blood flow to the brain. In addition, our findings indicate that such variability in cerebral blood flow negatively impacts on struggle phase duration, and thus impairs breath holding performance.
dc.description.peerreviewedYes
dc.description.publicationstatusYes
dc.format.extent688481 bytes
dc.format.mimetypeapplication/pdf
dc.languageEnglish
dc.language.isoeng
dc.publisherPublic Library of Science
dc.publisher.placeUnited States
dc.relation.ispartofstudentpublicationN
dc.relation.ispartofpagefrome66950-1
dc.relation.ispartofpagetoe66950-10
dc.relation.ispartofissue6
dc.relation.ispartofjournalPloS One
dc.relation.ispartofvolume8
dc.rights.retentionY
dc.subject.fieldofresearchCardiovascular medicine and haematology not elsewhere classified
dc.subject.fieldofresearchcode320199
dc.titleThe Effects of Involuntary Respiratory Contractions on Cerebral Blood Flow during Maximal Apnoea in Trained Divers
dc.typeJournal article
dc.type.descriptionC1 - Articles
dc.type.codeC - Journal Articles
gro.rights.copyright© 2013 Cross et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
gro.date.issued2013
gro.hasfulltextFull Text
gro.griffith.authorKavanagh, Justin J.


Files in this item

This item appears in the following Collection(s)

  • Journal articles
    Contains articles published by Griffith authors in scholarly journals.

Show simple item record