Document Detail


Dynamic deformation characteristics of porcine aortic valve leaflet under normal and hypertensive conditions.
MedLine Citation:
PMID:  19915178     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Calcific aortic valve (AV) disease has a high prevalence in the United States, and hypertension is correlated to early onset of the disease. The cause of the disease is poorly understood, although biological and remodeling responses to mechanical forces, such as membrane tension, have been hypothesized to play a role. The mechanical behavior of the native AV has, therefore, been the focus of many recent studies. In the present study, the dynamic deformation characteristics of the AV leaflet and the effects of hypertension on leaflet deformation are quantified. Whole porcine aortic roots were trimmed and mounted in an in vitro pulsatile flow loop and subjected to normal (80/120 mmHg), hypertensive (120/160 mmHg), or severe hypertensive (150/190 mmHg) conditions. Local valve leaflet deformations were calculated with dual-camera photogrammetry method: by tracking the motion of markers placed on the AV leaflets in three dimensions and calculating their spatial deformations. The results demonstrate that, first, during diastole, high transvalvular pressure induces a stretch waveform which plateaus over the diastolic duration in both circumferential and radial directions. During systole, the leaflet stretches in the radial direction due to forward flow drag forces but compresses in the circumferential direction in a manner in agreement with Poisson's effect. Second, average diastolic and systolic stretch ratios were quantified in the radial and circumferential directions in the base and belly region of the leaflet, and diastolic stretch was found to increase with increasing pressure conditions.
Authors:
Choon Hwai Yap; Hee-Sun Kim; Kartik Balachandran; Michael Weiler; Rami Haj-Ali; Ajit P Yoganathan
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Publication Detail:
Type:  Comparative Study; Journal Article     Date:  2009-11-13
Journal Detail:
Title:  American journal of physiology. Heart and circulatory physiology     Volume:  298     ISSN:  1522-1539     ISO Abbreviation:  Am. J. Physiol. Heart Circ. Physiol.     Publication Date:  2010 Feb 
Date Detail:
Created Date:  2010-01-21     Completed Date:  2010-02-16     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  100901228     Medline TA:  Am J Physiol Heart Circ Physiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  H395-405     Citation Subset:  IM    
Affiliation:
School of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA 30332, USA.
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MeSH Terms
Descriptor/Qualifier:
Animals
Aorta / pathology,  physiopathology
Aortic Valve / pathology*,  physiopathology*
Biomechanics
Blood Pressure / physiology
Disease Models, Animal
Female
Heart Ventricles / pathology,  physiopathology
Hypertension / pathology*,  physiopathology*
Models, Biological
Regional Blood Flow / physiology*
Swine

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


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