title: Variable open-end wave reflection in the pulmonary arteries of anesthetized sheep.
abstract: The aim of this study was to re-evaluate wave reflection in the healthy pulmonary arteries of sheep utilizing the time-domain-based method of wave intensity analysis. A thorough understanding of patterns of wave reflection during health and disease may provide future sensitive markers of early pulmonary vascular disease. Wave intensity was calculated from the simultaneous acquisition of proximal pulmonary arterial pressure and velocity in 12 anesthetized open-chest sheep. Normal pulmonary arterial wave speed was 2.1 ± 0.3 m s(-1). The incident forward compression wave generated by right ventricular systole was reflected in an open-end manner as a backward expansion wave from a site 3 cm downstream, corresponding to the main pulmonary bifurcation, and in a closed-end manner as a backward compression wave from a site 21 cm downstream, corresponding to the pulmonary microcirculation. The proximal open-end reflection site was not present throughout the entire cardiac cycle. Wave reflection was minimal with only 1% of the incident forward compression wave energy reflected as a backward expansion wave and 2% as a backward compression wave. The normal pulmonary artery in open-chest sheep is characterized by variable proximal open-end reflection from the main pulmonary bifurcation and fixed closed-end reflection from the microcirculation, generating backward-travelling waves of minimal intensity.
authors.affiliation: Discipline of Medicine, University of Tasmania Clinical School, Hobart, TAS, Australia. ndwyer@utas.edu.au
authors.forename: Nathan
authors.initials: N
authors.lastname: Dwyer
authors.forename: Ah Chot
authors.initials: AC
authors.lastname: Yong
authors.forename: David
authors.initials: D
authors.lastname: Kilpatrick
mesh_terms: D000818:Animals; D001783:Blood Flow Velocity; D008168:Lung / Q000098:blood supply; D008833:Microcirculation / Q000502:physiology*; D011651:Pulmonary Artery / Q000502:physiology*; D011652:Pulmonary Circulation / Q000502:physiology*; D011673:Pulsatile Flow; D034561:Sheep, Domestic; D016278:Ventricular Function, Right
references.citation: Am J Physiol Heart Circ Physiol. 2004 Jan;286(1):H267-75
references.pmid: 14512278
references.citation: J Biomech. 2001 Sep;34(9):1145-55
references.pmid: 11506785
references.citation: Am J Physiol Heart Circ Physiol. 2001 Aug;281(2):H895-902
references.pmid: 11454596
references.citation: J Biomech. 1979;12(5):373-95
references.pmid: 447757
references.citation: Heart Vessels. 1998;13(3):103-13
references.pmid: 10328180
references.citation: Circ Res. 1980 Apr;46(4):564-74
references.pmid: 7357704
references.citation: Heart Vessels. 2002 Mar;16(3):91-8
references.pmid: 12027238
references.citation: J Appl Physiol. 1962 May;17:492-6
references.pmid: 13895584
references.citation: Circ Res. 1973 Aug;33(2):190-7
references.pmid: 4727370
references.citation: Circ Res. 1978 May;42(5):593-7
references.pmid: 639181
references.citation: Am J Physiol Heart Circ Physiol. 2008 Aug;295(2):H482-90
references.pmid: 18515650
references.citation: J Physiol. 1965 May;178:193-210
references.pmid: 14298115
references.citation: Am J Physiol Heart Circ Physiol. 2006 Feb;290(2):H878-85
references.pmid: 16126811
references.citation: Circulation. 2006 Apr 11;113(14):1768-78
references.pmid: 16585389
references.citation: Am J Physiol. 1982 Feb;242(2):H154-60
references.pmid: 7065148
references.citation: Med Biol Eng Comput. 2009 Feb;47(2):175-88
references.pmid: 19205773
references.citation: Med Biol Eng Comput. 2007 Dec;45(12):1201-10
references.pmid: 17710460
references.citation: Med Eng Phys. 2004 Jan;26(1):23-9
references.pmid: 14644595
references.citation: J Biomech. 2002 Jun;35(6):775-83
references.pmid: 12020997
references.citation: Can J Cardiol. 2011 May-Jun;27(3):389.e1-10
references.pmid: 21601775
references.citation: J Biomech Eng. 1990 Aug;112(3):322-6
references.pmid: 2214715
references.citation: Am J Physiol. 1982 Feb;242(2):H197-202
references.pmid: 7065152
references.citation: Circ Res. 1966 Sep;19(3):467-80
references.pmid: 5925148
references.citation: J Biomech. 2009 Jul 22;42(10):1574-1577
references.pmid: 19426982
references.citation: Cardiovasc Res. 1991 Feb;25(2):118-24
references.pmid: 1742762
references.citation: Heart Vessels. 1997;12(2):53-9
references.pmid: 9403308
references.citation: Heart Vessels. 1997;Suppl 12:128-34
references.pmid: 9476563
references.citation: Clin Sci (Lond). 2001 Dec;101(6):749-57
references.pmid: 11724665
references.citation: Circ Res. 1970 Dec;27(6):955-1001
references.pmid: 5487081
references.citation: Am J Physiol Regul Integr Comp Physiol. 2008 May;294(5):R1554-62
references.pmid: 18287223