Document Detail


Prediction of pressure recovery location in aortic valve stenosis: an in-vitro validation study.
MedLine Citation:
PMID:  17944120     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND AND AIM OF THE STUDY: Pressure recovery is a source of discrepancy between Doppler-derived and catheter aortic valve pressure drops. Pressure recovery occurs where the stenotic jet reattaches to the aortic wall. An equation to predict the jet reattachment location has been developed based on the density and viscosity of blood, the velocity in the stenotic jet, and the aortic root and valve areas. The study aim was to define the conditions where this equation is valid and could be accurately applied to Doppler echocardiographic data. METHODS: In a pulse duplicator, mean flow rates were varied between 2 and 5 l/min, and anatomic orifice areas between 0.32 and 2.85 cm2, to produce values of the ratio of anatomic valve area to the aortic root area (E) of 0.04 to 0.36. For each hemodynamic state, continuous-wave, pulsed-wave Doppler and color Doppler flow maps were recorded. Instantaneous flow rates and pressures proximal and distal to the valve were recorded. Calculated reattachment lengths were compared to measurements from color Doppler echocardiography. RESULTS: Except for the smallest E value, there was a correlation between the predicted and measured jet reattachment lengths. The equation was good for predicted attachment lengths of less than 5 cm. Overestimation was seen for the smallest E value, representing a critically stenotic valve. CONCLUSION: Except for the most severe stenoses, pressure drops for aortic valves are best measured with the aortic sensor placed approximately 5 cm above the aortic valve. For moderate stenoses, where pressure recovery is relevant, the site of fully recovered pressure can be predicted.
Authors:
Katherine D Rhodes; Joel A Stroml; Muhammad M Rahman; Michael D VanAuker
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Validation Studies    
Journal Detail:
Title:  The Journal of heart valve disease     Volume:  16     ISSN:  0966-8519     ISO Abbreviation:  J. Heart Valve Dis.     Publication Date:  2007 Sep 
Date Detail:
Created Date:  2007-10-19     Completed Date:  2008-02-14     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  9312096     Medline TA:  J Heart Valve Dis     Country:  England    
Other Details:
Languages:  eng     Pagination:  489-94     Citation Subset:  IM    
Affiliation:
Departments of Chemical Engineering, University of South Florida, Tampa, Florida 33620, USA.
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MeSH Terms
Descriptor/Qualifier:
Algorithms
Aortic Valve / physiology*
Aortic Valve Stenosis / physiopathology*
Blood Flow Velocity / physiology
Blood Viscosity / physiology
Echocardiography, Doppler, Color / methods*
Heart Catheterization / methods*
Humans
Models, Biological
Models, Cardiovascular*

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


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