Profound hyperventilation and development of periodic breathing during exceptional orthostatic stress in a 21-year-old man

Research output: Contribution to journalArticlepeer-review


  • J. Donnelly
  • Sam Lucas
  • K.N. Thomas
  • S.D. Galvin
  • P.N. Ainslie

Colleges, School and Institutes

External organisations

  • University of Otago
  • University of British Columbia


In this case report we describe a trial of experimentally induced syncope in a healthy young volunteer that produced abnormal periods of hyperventilation (V̇A=57 L/min) and periodic breathing; the latter persisting for approximately 60. min following termination of the trial. In this example, independent of systemic hypotension, the severe hyperventilation and related hypocapnia (end-tidal PETCO2~5 mm Hg) induced by orthostatic stress (lower body negative pressure) resulted in a ~65% reduction in cerebral blood flow velocity. Potential mechanisms underlying these striking cardiorespiratory patterns are discussed.


Original languageEnglish
Pages (from-to)66-70
Number of pages5
JournalRespiratory physiology & neurobiology
Issue number1
Publication statusPublished - 30 Jun 2011