| The relationship between pulmonary system impedance and right ventricular function in normal sheep. | |
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MedLine Citation:
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PMID: 19784871 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Right ventricular (RV) afterload is a key determinant of RV function and is increased in many cardiopulmonary pathologies. Pulmonary circulation input impedance has been used to quantify afterload previously but due to its complexity has not been widely applied. This study examines the effect of a subset of the impedance spectrum, the zeroth and first harmonic impedance moduli (Z (0), Z (1)), on RV performance in large animals. An artificial circuit with adjustable resistance and compliance (C) was implanted into the pulmonary circulation of five sheep. Resistance was varied to increase Z (0) in increments of 2 mmHg/(L/min) until Z (0) was 8 mmHg/(L/min) above baseline. At each Z (0), C was adjusted between 0, 0.5 and 2 mL/mmHg or 0, 1, and 5 mL/mmHg. Fourier transforms of the pulmonary artery pressure and flow in each situation were used to calculate the pulmonary impedance. Results show that the percent change in cardiac output (%DeltaCO) is linearly related to the change in Z (0) (DeltaZ (0)). Increases in Z (1) (DeltaZ (1)) decreased %DeltaCO but to a much smaller degree, with the effect of DeltaZ (1) increasing with DeltaZ (0). Regression of these results produce the equation: %DeltaCO = (-0.0829DeltaZ (1) - 3.65)DeltaZ (0) - 9.02 (R (2) = 0.69). Blood flow and pressure moduli are small at harmonics higher than the first and are unlikely to affect RV function. Therefore, during acute, high afterload states, Z (0) is the primary determinant of CO, while the effect of Z (1) is minor. |
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Authors:
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Alexander S Kuo; Hitoshi Sato; Junewai L Reoma; Keith E Cook |
Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: Cardiovascular engineering (Dordrecht, Netherlands) Volume: 9 ISSN: 1573-6806 ISO Abbreviation: Cardiovasc Eng Publication Date: 2009 Dec |
Date Detail:
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Created Date: 2010-01-21 Completed Date: 2010-04-05 Revised Date: - |
Medline Journal Info:
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Nlm Unique ID: 101132083 Medline TA: Cardiovasc Eng Country: Netherlands |
Other Details:
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Languages: eng Pagination: 153-60 Citation Subset: IM |
Affiliation:
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Department of Surgery, University of Michigan, B560B MSRBII, 1150 W. Medical Center Dr., Ann Arbor, MI, 48109, USA. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Animals Computer Simulation Lung / physiology* Lung Compliance / physiology* Models, Cardiovascular* Sheep / physiology* Statistics as Topic Ventricular Function, Right / physiology* |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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