Document Detail


Effects of exercise and respiration on hemodynamic efficiency in CFD simulations of the total cavopulmonary connection.
MedLine Citation:
PMID:  17171509     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Congenital heart defects with a single functional ventricle, such as hypoplastic left heart syndrome and tricuspid atresia, require a staged surgical approach to separate the systemic and pulmonary circulations. Ultimately, the venous or pulmonary side of the heart is bypassed by directly connecting the vena cava to the pulmonary arteries with a modified t-shaped junction. The Fontan procedure (total cavopulmonary connection, TCPC) completes this process of separation. To date, computational fluid dynamics (CFD) simulations in this low pressure, passive flow, intrathoracic system have neglected the presumed important effects of respiration on physiology and higher "stress" states such as with exercise have never been considered. We hypothesize that incorporating effects of respiration and exercise would provide more realistic estimates of TCPC performance. Time-dependent, 3D blood flow simulations are performed by a custom finite element solver for two patient-specific Fontan models with a novel respiration model, developed to generate physiologic time-varying flow conditions. Blood flow features, pressure, and energy efficiency are analyzed at rest and with increasing flow rates to simulate exercise conditions. The simulations produce realistic pressure and flow data, comparable to that measured by catheterization and echocardiography, and demonstrate substantial increases in energy dissipation (i.e. decreased performance) with exercise and respiration due to increasing intensity of small scale vortices in the flow. As would be expected, these changes are highly dependent on patient-specific anatomy and Fontan geometry. We propose that respiration and exercise should be incorporated into TCPC CFD simulations to provide increasingly realistic evaluations of TCPC performance.
Authors:
Alison L Marsden; Irene E Vignon-Clementel; Frandics P Chan; Jeffrey A Feinstein; Charles A Taylor
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, Non-P.H.S.     Date:  2006-12-15
Journal Detail:
Title:  Annals of biomedical engineering     Volume:  35     ISSN:  0090-6964     ISO Abbreviation:  Ann Biomed Eng     Publication Date:  2007 Feb 
Date Detail:
Created Date:  2007-01-15     Completed Date:  2007-03-20     Revised Date:  2008-11-21    
Medline Journal Info:
Nlm Unique ID:  0361512     Medline TA:  Ann Biomed Eng     Country:  United States    
Other Details:
Languages:  eng     Pagination:  250-63     Citation Subset:  IM    
Affiliation:
Pediatrics Department, Stanford University, Clark Center E350, Stanford, CA 94305, USA. amarsden@stanford.edu
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MeSH Terms
Descriptor/Qualifier:
Blood Flow Velocity / physiology*
Blood Pressure / physiology
Computer Simulation
Heart Bypass, Right / methods*
Humans
Models, Cardiovascular*
Physical Exertion / physiology*
Pulmonary Artery / physiology*,  surgery
Respiratory Mechanics / physiology*
Venae Cavae / physiology*,  surgery

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


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