Document Detail

Stroke volume of the heart and thoracic fluid content during head-up and head-down tilt in humans.
MedLine Citation:
PMID:  16146465     Owner:  NLM     Status:  MEDLINE    
BACKGROUND: The stroke volume (SV) of the heart depends on the diastolic volume but, for the intact organism, central pressures are applied widely to express the filling of the heart. METHODS: This study evaluates the interdependence of SV and thoracic electrical admittance of thoracic fluid content (TA) vs. the central venous (CVP), mean pulmonary artery (MPAP) and pulmonary artery wedge (PAWP) pressures during head-up (HUT) and head-down (HDT) tilt in nine healthy humans. RESULTS: From the supine position to 20 degrees HDT, SV [112 +/- 18 ml; mean +/- standard deviation (SD)], TA (30.8 +/- 7.1 mS) and CVP (3.6 +/- 0.9 mmHg) did not change significantly, whereas MPAP (from 13.9 +/- 2.7 to 16.1 +/- 2.5 mmHg) and PAWP (from 8.8 +/- 3.4 to 11.3 +/- 2.5 mmHg; P < 0.05) increased. Conversely, during 70 degrees HUT, SV (to 65 +/- 24 ml) decreased, together with CVP (to 0.9 +/- 1.4 mmHg; P < 0.001), MPAP (to 9.3 +/- 3.8 mmHg; P < 0.01), PAWP (to 0.7 +/- 3.3 mmHg; P < 0.001) and TA (to 26.7 +/- 6.8 mS; P < 0.01). However, from 20 to 50 min of HUT, SV decreased further (to 48 +/- 21 ml; P < 0.001), whereas the central pressures did not change significantly. CONCLUSIONS: During both HUT and HDT, SV of the heart changed with the thoracic fluid content rather than with the central vascular pressures. These findings confirm that the function of the heart relates to its volume rather than to its so-called filling pressures.
J J van Lieshout; M P M Harms; F Pott; M Jenstrup; N H Secher
Related Documents :
9068805 - The capnography-tilt test for the diagnosis of hyperventilation syncope.
11154825 - Respiratory responses of normal and vestibular defective human subjects to rotation in ...
464105 - Vagal and sinoaortic reflexes in postural control of circulation and renin release.
17947365 - Influence of respiratory instability during neurocardiogenic presyncope on cerebrovascu...
3278765 - The bolus tie-over "pressure" dressing in the management of full thickness skin grafts....
2933035 - Sodium ion stimulates the release of atrial natriuretic polypeptides (anp) from rat atria.
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Acta anaesthesiologica Scandinavica     Volume:  49     ISSN:  0001-5172     ISO Abbreviation:  Acta Anaesthesiol Scand     Publication Date:  2005 Oct 
Date Detail:
Created Date:  2005-09-08     Completed Date:  2005-12-15     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0370270     Medline TA:  Acta Anaesthesiol Scand     Country:  Denmark    
Other Details:
Languages:  eng     Pagination:  1287-92     Citation Subset:  IM    
Department of Medicine, Medium Care Unit, University of Amsterdam, Amsterdam, the Netherlands.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Body Fluids / physiology*
Cardiac Output / physiology
Central Venous Pressure / physiology
Electric Impedance
Head-Down Tilt / physiology*
Heart / physiology*
Posture / physiology*
Pulmonary Artery / physiology
Pulmonary Wedge Pressure / physiology
Stroke Volume / physiology*
Supine Position / physiology
Thorax / physiology

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Increasing cardiac output by fluid loading: effects on indocyanine green plasma disappearance rate a...
Next Document:  Hyperbaric oxygen attenuation of lipopolysaccharide-induced acute lung injury involves heme oxygenas...