Impact of finite orifice size on proximal flow convergence. Implications for Doppler quantification of valvular regurgitation.
Why the study?
Does applying a correction factor for finite orifice size improve the accuracy of Doppler quantification of regurgitant flow rate?
Population
Numerical and in vitro models of flow through 0.3 and 1.0 cm2 circular orifices with flow rates from 4.3 to…
Comparison
Application of a correction factor predicted by… vs Standard calculation assuming hemispheric symmetry
Design
Preclinical
Authors
Discussion
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Implication
Finite orifice correction improves flow accuracy in animals; leaves open validation for clinical regurgitant quantification.
Key Points
- The study aims to assess how finite orifice size affects the accuracy of Doppler quantification of valvular regurgitation flow rates.
- Conducted numerical and in vitro modeling to analyze flow dynamics around finite orifices.
- Used Doppler imaging to measure flow rates through circular orifices of varying sizes.
- Correlated modeled flow rates with actual flow measurements to validate assumptions of hemispheric symmetry.
- Calculated flow correlated well with true flow (Qc = 0.88Qo - 7.82) with r = 0.945, p < 0.0001.
- Flow was underestimated as the measured velocity approached orifice velocity.
- Applying a correction factor improved estimated flow rates from an error of -13.81 cm3/sec to +1.54 cm3/sec.
Structured PICO
Does applying a correction factor for finite orifice size improve the accuracy of Doppler quantification of regurgitant flow rate?
P
Population
Numerical and in vitro models of flow through 0.3 and 1.0 cm2 circular orifices with flow rates from 4.3 to 150 cm3/sec
I
Intervention
Application of a correction factor predicted by numerical modeling to account for finite orifice size
C
Comparator
Standard calculation assuming hemispheric symmetry (infinitesimal orifice)
O
Outcome
Accuracy of calculated flow rate (Qc) compared to true flow rate (Qo)surrogate
Accounting for finite orifice size with a correction factor significantly improves the accuracy of the proximal flow convergence method for quantifying regurgitant flow.
Cite This Study
Rodriguez et al. (1992) studied this question.