Document Detail

Pressure recovery explains doppler overestimation of invasive pressure gradient across segmental vascular stenosis.
MedLine Citation:
PMID:  19845724     Owner:  NLM     Status:  MEDLINE    
AIMS: This investigation sought to discern the accuracy of Doppler predictions of pressure drops in stenotic jets mimicking aortic coarctation (AC) across a broad spectrum of conditions, using an in vitro nonpulsatile flow model. METHODS AND RESULTS: The model allowed for different AC diameter and length, different cardiac output, and different diameter of the aorta distal to the AC. For each study condition, pressure drops across a model of AC were measured both noninvasively using the simplified Bernoulli equation (SBE) and invasively using the instantaneous actual pressure gradient. We observed a good correlation of SBE-predicted and actual pressure gradients (slope = 0.929; r = 0.907, P < 0.0001) when AC diameter was small and the diameter of the aorta distal to the AC was large. However, we observed various degrees of overestimation by Doppler when mild AC was simulated (P = 0.0003), or when the diameter of the aorta distal to the coarctation was reduced (P < 0.0001). Increased AC length was associated with underestimation of actual pressure gradient by Doppler when AC diameter was small. Accounting for pressure recovery and viscous losses reduced the discrepancies between Doppler-predicted and actual pressure gradients in all study conditions (slope = 0.964; r = 0.989, P < 0.0001). CONCLUSIONS: Caution should be used in applying the SBE to the noninvasive assessment of AC severity. Significant segmental stenosis is associated with significant underestimation of the actual pressure gradient because of viscous losses. A substantial overestimation of the actual pressure drop due to a pressure recovery effect may occur in mild AC, especially when the distal aorta is not dilated.
Alessandro Giardini; Theresa A Tacy
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Publication Detail:
Type:  Journal Article     Date:  2009-10-20
Journal Detail:
Title:  Echocardiography (Mount Kisco, N.Y.)     Volume:  27     ISSN:  1540-8175     ISO Abbreviation:  Echocardiography     Publication Date:  2010 Jan 
Date Detail:
Created Date:  2010-04-12     Completed Date:  2010-07-22     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  8511187     Medline TA:  Echocardiography     Country:  United States    
Other Details:
Languages:  eng     Pagination:  21-31     Citation Subset:  IM    
Cardiorespiratory Unit, Great Ormond Street Hospital for Children, London, United Kingdom.
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MeSH Terms
Aorta / ultrasonography*
Aortic Coarctation / complications,  physiopathology*,  ultrasonography*
Aortic Valve Stenosis / etiology,  physiopathology*,  ultrasonography*
Blood Pressure
Echocardiography, Doppler / methods*
Image Interpretation, Computer-Assisted / methods*
Phantoms, Imaging
Reproducibility of Results
Sensitivity and Specificity

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

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