Estimation of the Aortic Orifice Area: Comparison of the Classical and Modified Forms of the Continuity Equation

1993 ◽  
Vol 7 (5) ◽  
pp. 259-262
Author(s):  
J. Chambers ◽  
G. Spiropoulos
Keyword(s):  
Continuity Equation ◽  
Orifice Area ◽  
Aortic Orifice ◽  
Modified Forms

scholarly journals Analysis of the Effect of Flow Rate on the Doppler Continuity Equation for Stenotic Orifice Area Calculations

Circulation ◽  
1998 ◽  
Vol 97 (16) ◽  
pp. 1597-1605 ◽  
Author(s):  
Curt G. DeGroff ◽  
Robin Shandas ◽  
Lilliam Valdes-Cruz
Keyword(s):  
Flow Rate ◽  
Continuity Equation ◽  
Orifice Area

scholarly journals Aliased Flow Signal Planimetry by Cardiovascular Magnetic Resonance Imaging for Grading Aortic Stenosis Severity: A Prospective Pilot Study

2021 ◽  
Vol 8 ◽  
Author(s):  
Cesare Mantini ◽  
Mohammed Y. Khanji ◽  
Emilia D'Ugo ◽  
Marzia Olivieri ◽  
Cristiano Giovanni Caputi ◽  
...  
Keyword(s):  
Cardiovascular Magnetic Resonance ◽  
Magnetic Resonance ◽  
Aortic Stenosis ◽  
Phase Contrast ◽  
Continuity Equation ◽  
Intraclass Correlation ◽  
Invasive Technique ◽  
Effective Orifice Area ◽  
Contrast Imaging ◽  
Orifice Area

Objectives: Transthoracic echocardiography (TTE) is the standard technique for assessing aortic stenosis (AS), with effective orifice area (EOA) recommended for grading severity. EOA is operator-dependent, influenced by a number of pitfalls and requires multiple measurements introducing independent and random sources of error. We tested the diagnostic accuracy and precision of aliased orifice area planimetry (AOAcmr), a new, simple, non-invasive technique for grading of AS severity by low-VENC phase-contrast cardiovascular magnetic resonance (CMR) imaging.Methods: Twenty-two consecutive patients with mild, moderate, or severe AS and six age- and sex-matched healthy controls had TTE and CMR examinations on the same day. We performed analysis of agreement and correlation among (i) AOAcmr; (ii) geometric orifice area (GOAcmr) by direct CMR planimetry; (iii) EOAecho by TTE-continuity equation; and (iv) the “gold standard” multimodality EOA (EOAhybrid) obtained by substituting CMR LVOT area into Doppler continuity equation.Results: There was excellent pairwise positive linear correlation among AOAcmr, EOAhybrid, GOAcmr, and EOAecho (p < 0.001); AOAcmr had the highest correlation with EOAhybrid (R2 = 0.985, p < 0.001). There was good agreement between methods, with the lowest bias (0.019) for the comparison between AOAcmr and EOAhybrid. AOAcmr yielded excellent intra- and inter-rater reliability (intraclass correlation coefficient: 0.997 and 0.998, respectively).Conclusions: Aliased orifice area planimetry by 2D phase contrast imaging is a simple, reproducible, accurate “one-stop shop” CMR method for grading AS, potentially useful when echocardiographic severity assessment is inconclusive or discordant. Larger studies are warranted to confirm and validate these promising preliminary results.

Comparison of continuity equation and Gorlin formula effective orifice area of aortic valve prostheses: an intraoperative study

2002 ◽  
Vol 19 (Supplement 27) ◽  
pp. 11 ◽  
Author(s):  
V. Rudolph ◽  
M. Hartrumpf ◽  
C. Schelenz ◽  
E. Hüttemann ◽  
J. M. Albes ◽  
...  
Keyword(s):  
Aortic Valve ◽  
Continuity Equation ◽  
Effective Orifice Area ◽  
Orifice Area ◽  
Valve Prostheses

scholarly journals Comparison of effective orifice area calculations using the continuity equation in steady and pulsatile flow

1996 ◽  
Vol 27 (2) ◽  
pp. 233 ◽  
Author(s):  
Nelson P. Trujillo ◽  
Jeffrey Kwon ◽  
Mark Kringlen ◽  
Edward Gill ◽  
Robin Shandas ◽  
...  
Keyword(s):  
Pulsatile Flow ◽  
Continuity Equation ◽  
Effective Orifice Area ◽  
Orifice Area
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