Prior head-down tilt does not impair the cerebrovascular response to head-up tilt

Journal of Applied Physiology
Changbin YangR L Hughson

Abstract

The hypothesis that cerebrovascular autoregulation was not impaired during head-up tilt (HUT) that followed brief exposures to varying degrees of prior head-down tilt (HDT) was tested in 10 healthy young men and women. Cerebral mean flow velocity (MFV) and cardiovascular responses were measured in transitions to a 60-s period of 75° HUT that followed supine rest (control) or 15 s HDT at -10°, -25°, and -55°. During HDT, heart rate (HR) was reduced for -25° and -55°, and cardiac output was lower at -55° HDT. MFV increased during -10° HDT, but not in the other conditions even though blood pressure at the middle cerebral artery (BPMCA) increased. On the transition to HUT, HR increased only for -55° condition, but stroke volume and cardiac output transiently increased for -25° and -55°. Total peripheral resistance index decreased in proportion to the magnitude of HDT and recovered over the first 20 s of HUT. MFV was significantly less in all HDT conditions compared with the control in the first 5-s period of HUT, but it recovered quickly. An autoregulation correction index derived from MFV recovery relative to BPMCA decline revealed a delay in the first 5 s for prior HDT compared with control but then a rapid increase to briefly ex...Continue Reading

References

Jan 1, 1989·Stroke; a Journal of Cerebral Circulation·R AaslidH Nornes
Sep 24, 1998·The American Journal of Physiology·C P DoeR Hainsworth
Aug 6, 2000·Stroke; a Journal of Cerebral Circulation·L A LipsitzV Babikian
Jul 7, 2001·Stroke; a Journal of Cerebral Circulation·J J van LieshoutN H Secher
Oct 6, 2001·Stroke; a Journal of Cerebral Circulation·R L HughsonJ K Shoemaker
Mar 16, 2002·Journal of Applied Physiology·Karin Toska, Lars Walløe
Feb 7, 2003·Journal of Applied Physiology·Johannes J Van LieshoutNiels H Secher
Apr 28, 2005·Neuroscience Letters·Cong Chi Denis TranCharles-Yannick Guézennec
Jul 15, 2005·American Journal of Physiology. Regulatory, Integrative and Comparative Physiology·J GisolfJ M Karemaker
Jul 15, 2005·American Journal of Physiology. Regulatory, Integrative and Comparative Physiology·James W Hicks, James R Munis
Nov 25, 2005·American Journal of Physiology. Regulatory, Integrative and Comparative Physiology·J M SerradorA W Gelb
Jan 4, 2007·Clinical Science·Wouter WielingMichael E Tschakovsky
Apr 28, 2007·Journal of Applied Physiology·Don D SheriffKarin Toska
Oct 7, 2008·Ultrasound in Medicine & Biology·Farzaneh A SorondLewis A Lipsitz
Jul 4, 2009·Journal of Applied Physiology·Rogier V ImminkJohannes J Van Lieshout
Jan 9, 2010·Journal of Applied Physiology·Don D SheriffKarin Toska
Aug 7, 2010·Journal of Applied Physiology·B M DeeganJ M Serrador
Feb 2, 2013·Journal of Applied Physiology·K A ZujR L Hughson
Jul 12, 2014·Journal of Applied Physiology·Nicole S CoverdaleJ Kevin Shoemaker

❮ Previous
Next ❯

Citations

Aug 28, 2015·American Journal of Physiology. Regulatory, Integrative and Comparative Physiology·Shigehiko OgohHervé Normand
Jul 29, 2020·Frontiers in Physiology·Marc KermorgantAnne Pavy-Le Traon

❮ Previous
Next ❯

Related Concepts

Related Feeds

Antifungals (ASM)

An antifungal, also known as an antimycotic medication, is a pharmaceutical fungicide or fungistatic used to treat and prevent mycosis such as athlete's foot, ringworm, candidiasis, cryptococcal meningitis, and others. Discover the latest research on antifungals here.

Antifungals

An antifungal, also known as an antimycotic medication, is a pharmaceutical fungicide or fungistatic used to treat and prevent mycosis such as athlete's foot, ringworm, candidiasis, cryptococcal meningitis, and others. Discover the latest research on antifungals here.