Flow diffuser characteristics of St. Jude heart valve prosthesis: Doppler and catheter transvalvular gradient measurements

Neil L. Greenberg; Pieter M. Vandervoort; James D. Thomas

Flow diffuser characteristics of St. Jude heart valve prosthesis: Doppler and catheter transvalvular gradient measurements

Neil L. Greenberg^*, Pieter M. Vandervoort, James D. Thomas

^*Corresponding author for this work

Medicine, Cardiology Division

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

Abstract

The flow diffuser characteristics of the St. Jude heart valve were investigated and compared to theoretical calculations based on the two dimensional geometry of the valve. Pressure recovery (C_p) and loss (K) coefficients were calculated for varying sized prostheses in both mitral and aortic valve configurations over a range of steady flow rates. In vitro experiments demonstrated that the pressure recovery (C_p=0.36±0.04) and loss (K=0.64±0.04) coefficients for flow through the central orifice were independent of the valve sizes and configurations examined. Comparison of ideal and experimentally determined pressure recovery coefficients yielded diffuser effectiveness (η=0.62). We applied these flow diffuser characteristics to investigate the discrepancies between Doppler and catheter gradients across prosthetic St. Jude bileaflet valves. Transvalvular Doppler gradients can be reconciled with catheter measurements by multiplying the Doppler gradient by the pressure loss coefficient (K=0.64) (r=0.99, y=1.11×-0.19).

Original language	English (US)
Title of host publication	Advances in Bioengineering
Publisher	ASME
Pages	303-304
Number of pages	2
Volume	28
State	Published - Dec 1 1994
Event	Proceedings of the 1994 International Mechanical Engineering Congress and Exposition - Chicago, IL, USA Duration: Nov 6 1994 → Nov 11 1994

Other

Other	Proceedings of the 1994 International Mechanical Engineering Congress and Exposition
City	Chicago, IL, USA
Period	11/6/94 → 11/11/94

ASJC Scopus subject areas

Engineering(all)

Cite this

@inproceedings{4a957f9d89af466697193b382262ec94,

title = "Flow diffuser characteristics of St. Jude heart valve prosthesis: Doppler and catheter transvalvular gradient measurements",

abstract = "The flow diffuser characteristics of the St. Jude heart valve were investigated and compared to theoretical calculations based on the two dimensional geometry of the valve. Pressure recovery (Cp) and loss (K) coefficients were calculated for varying sized prostheses in both mitral and aortic valve configurations over a range of steady flow rates. In vitro experiments demonstrated that the pressure recovery (Cp=0.36±0.04) and loss (K=0.64±0.04) coefficients for flow through the central orifice were independent of the valve sizes and configurations examined. Comparison of ideal and experimentally determined pressure recovery coefficients yielded diffuser effectiveness (η=0.62). We applied these flow diffuser characteristics to investigate the discrepancies between Doppler and catheter gradients across prosthetic St. Jude bileaflet valves. Transvalvular Doppler gradients can be reconciled with catheter measurements by multiplying the Doppler gradient by the pressure loss coefficient (K=0.64) (r=0.99, y=1.11×-0.19).",

author = "Greenberg, {Neil L.} and Vandervoort, {Pieter M.} and Thomas, {James D.}",

year = "1994",

month = dec,

day = "1",

language = "English (US)",

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note = "Proceedings of the 1994 International Mechanical Engineering Congress and Exposition ; Conference date: 06-11-1994 Through 11-11-1994",

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TY - GEN

T1 - Flow diffuser characteristics of St. Jude heart valve prosthesis

T2 - Proceedings of the 1994 International Mechanical Engineering Congress and Exposition

AU - Greenberg, Neil L.

AU - Vandervoort, Pieter M.

AU - Thomas, James D.

PY - 1994/12/1

Y1 - 1994/12/1

N2 - The flow diffuser characteristics of the St. Jude heart valve were investigated and compared to theoretical calculations based on the two dimensional geometry of the valve. Pressure recovery (Cp) and loss (K) coefficients were calculated for varying sized prostheses in both mitral and aortic valve configurations over a range of steady flow rates. In vitro experiments demonstrated that the pressure recovery (Cp=0.36±0.04) and loss (K=0.64±0.04) coefficients for flow through the central orifice were independent of the valve sizes and configurations examined. Comparison of ideal and experimentally determined pressure recovery coefficients yielded diffuser effectiveness (η=0.62). We applied these flow diffuser characteristics to investigate the discrepancies between Doppler and catheter gradients across prosthetic St. Jude bileaflet valves. Transvalvular Doppler gradients can be reconciled with catheter measurements by multiplying the Doppler gradient by the pressure loss coefficient (K=0.64) (r=0.99, y=1.11×-0.19).

AB - The flow diffuser characteristics of the St. Jude heart valve were investigated and compared to theoretical calculations based on the two dimensional geometry of the valve. Pressure recovery (Cp) and loss (K) coefficients were calculated for varying sized prostheses in both mitral and aortic valve configurations over a range of steady flow rates. In vitro experiments demonstrated that the pressure recovery (Cp=0.36±0.04) and loss (K=0.64±0.04) coefficients for flow through the central orifice were independent of the valve sizes and configurations examined. Comparison of ideal and experimentally determined pressure recovery coefficients yielded diffuser effectiveness (η=0.62). We applied these flow diffuser characteristics to investigate the discrepancies between Doppler and catheter gradients across prosthetic St. Jude bileaflet valves. Transvalvular Doppler gradients can be reconciled with catheter measurements by multiplying the Doppler gradient by the pressure loss coefficient (K=0.64) (r=0.99, y=1.11×-0.19).

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M3 - Conference contribution

AN - SCOPUS:0028743498

VL - 28

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EP - 304

BT - Advances in Bioengineering

PB - ASME

Y2 - 6 November 1994 through 11 November 1994

ER -

Flow diffuser characteristics of St. Jude heart valve prosthesis: Doppler and catheter transvalvular gradient measurements

Abstract

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