| Intrapulmonary shunt during normoxic and hypoxic exercise in healthy humans. | |
| | |
MedLine Citation:
|
PMID: 17089877 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
This review presents evidence for the recruitment of intrapulmonary arteriovenous shunts (IPAVS) during exercise in normal healthy humans. Support for pre-capillary connections between the arterial and venous circulation in lungs of humans and animals have existed for over one-hundred years. Right-to-left physiological shunt has not been detected during exercise with gas exchange-dependent techniques. However, fundamental assumptions of these techniques may not allow for measurement of a small (1-3%) anatomical shunt, the magnitude of which would explain the entire A-aDO2 typically observed during normoxic exercise. Data from contrast echocardiograph studies are presented demonstrating the development of IPAVS with exercise in 90% of subjects tested. Technetium-99m labeled macroaggregated albumin studies also found exercise IPAVS and calculated shunt to be approximately 2% at max exercise. These exercise IPAVS appear strongly related to the alveolar to arterial PO2 difference, pulmonary blood flow and mean pulmonary artery pressure. Hypoxic exercise was found to induce IPAVS at lower workloads than during normoxic exercise in 50% of subjects, while all subjects continued to shunt during recovery from hypoxic exercise, but only three subjects demonstrated intrapulmonary shunt during recovery from normoxic exercise. We suggest that these previously under-appreciated intrapulmonary arteriovenous shunts develop during exercise, contributing to the impairment in gas exchange typically observed with exercise. Future work will better define the conditions for shunt recruitment as well as their physiologic consequence. |
| | |
Authors:
|
Andrew T Lovering; Michael K Stickland; Marlowe W Eldridge |
Related Documents
:
|
18465177 - Preoperative gender differences in pulmonary gas exchange in morbidly obese subjects. 15721127 - Utility of cardiopulmonary stress testing in assessing disease severity in children wit... 18634147 - Prevalence of exercise pulmonary arterial hypertension in scleroderma. 2743207 - The response of the pulmonary circulation to exercise during normoxia and hypoxia follo... 3203667 - Slow upward drift of vo2 during constant-load cycling in untrained subjects. 3814627 - Advantages of perfluorochemical perfusion in the isolated working rabbit heart preparat... |
Publication Detail:
|
Type: Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't; Review |
Journal Detail:
|
Title: Advances in experimental medicine and biology Volume: 588 ISSN: 0065-2598 ISO Abbreviation: Adv. Exp. Med. Biol. Publication Date: 2006 |
Date Detail:
|
Created Date: 2006-11-08 Completed Date: 2006-12-12 Revised Date: 2007-11-15 |
Medline Journal Info:
|
Nlm Unique ID: 0121103 Medline TA: Adv Exp Med Biol Country: United States |
Other Details:
|
Languages: eng Pagination: 31-45 Citation Subset: IM |
Affiliation:
|
The John Rankin Laboratory of Pulmonary Medicine, Department of Population Health Sciences, University of Wisconsin-Madison, Wisconsin, USA. atlovering@wisc.edu |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Albumins
/
metabolism Anoxia* / metabolism Capillaries / metabolism Echocardiography / methods* Exercise Heart / physiology* Humans Pulmonary Circulation Pulmonary Gas Exchange* Respiration* Respiratory Function Tests Technetium / metabolism Whole Body Imaging |
| Grant Support | |
ID/Acronym/Agency:
|
HL-15469-33/HL/NHLBI NIH HHS; T32 HL-07654-16/HL/NHLBI NIH HHS |
| Chemical | |
Reg. No./Substance:
|
0/Albumins; 7440-26-8/Technetium |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Exercise induced arterial hypoxemia: the role of ventilation-perfusion inequality and pulmonary diff...
Next Document: Exercise-induced arterial hypoxemia: consequences for locomotor muscle fatigue.