| Cardiovascular responses to short-term head-down positioning in healthy young and older adults. | |
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MedLine Citation:
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PMID: 15991485 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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BACKGROUND AND PURPOSE: Isolated head-down postural drainage is assumed to acutely load the cardiovascular system. Consequently, it is considered a relative contraindication in the presence of severe cardiovascular disease. Evidence demonstrating that the head-down manoeuvre as used by physiotherapists does significantly load the cardiovascular system is lacking. The present study documents the cardiovascular responses t short-term 30 degrees head-down positioning in healthy subjects. The results are a point of reference for respiratory patients with and without cardiovascular disease. METHOD: A quasi-experimental research design was used, with multiple measurements obtained at rest (long sitting and in the head-down position. Twenty-one young subjects (mean age 25 years (standard deviation, (SD) 3 years)) and 19 older subjects (mean age 66 years (SD 6 years)) were studied. Applanation tonometry and sphygmocardiography were used to measure temporal and pressure variables, and indices that estimate myocardial work and coronary blood flow. RESULTS: Absolute differences existed between the two age groups for all variables at rest (p < 0.001). No age-time interaction was observed for any variable in the head-down position (p > 0.05). Serial measures in the head-down position did not vary across time (p > 0.05). Small (<9%) but significant (p < or = 0.02) decreases in heart rate, relative diastolic duration, mean arterial blood pressure and diastolic time indices, and small (<12%) but significant (p < or = 0.002) increases in cardiac cycle time, ejection duration (relative and absolute) and absolute diastolic duration were observed in the head-down position compared with rest. A small (9%) but significant (p < 0.001) fall in the sub-endocardial viability ratio occurred in the head down position. CONCLUSION: The findings have little consequence in health, but they suggest that head-down postural drainage may be of concern for chest physiotherapy recipients with reduced cardiac reserve or impaired barorefilex function. |
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Authors:
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Justine M Naylor; Chin-Moi Chow; Anthony S McLean; Robert C Heard; Albert Avolio |
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Publication Detail:
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Type: Journal Article |
Journal Detail:
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Title: Physiotherapy research international : the journal for researchers and clinicians in physical therapy Volume: 10 ISSN: 1358-2267 ISO Abbreviation: Physiother Res Int Publication Date: 2005 |
Date Detail:
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Created Date: 2005-07-04 Completed Date: 2005-09-29 Revised Date: 2007-11-15 |
Medline Journal Info:
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Nlm Unique ID: 9612022 Medline TA: Physiother Res Int Country: England |
Other Details:
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Languages: eng Pagination: 32-47 Citation Subset: IM |
Affiliation:
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School of Exercise and Sport Sciences, University of Sydney, NSW, Australia. Justine.Naylor@swsahs.nsw.gov.au |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Adult Age Factors Aged Baroreflex / physiology* Blood Pressure Head-Down Tilt / physiology* Heart Rate Hemodynamics* Humans Male Middle Aged Myocardium / metabolism* Oxygen / metabolism* Oxygen Consumption |
| Chemical | |
Reg. No./Substance:
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7782-44-7/Oxygen |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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