Assessment of the severity of aortic regurgitation with pulsed wave Doppler velocity profile in the descending aorta

2014 ◽  
Vol 14 (5) ◽  
pp. 427-433
Author(s):  
Belma Kalayci ◽  
Suleyman Kalayci ◽  
Pinar Turker Bayir ◽  
Serkan Duyuler ◽  
Saadet Guven ◽  
...  
Keyword(s):  
Velocity Profile ◽  
Aortic Regurgitation ◽  
Doppler Velocity ◽  
Descending Aorta ◽  
Pulsed Wave Doppler

Abstract 12320: Assessment of Post-Procedural Aortic Regurgitation After Transcatheter Aortic Valve Replacement During the Procedure: An Intraprocedural Transesophageal Echocardiography Study

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Hirotsugu Mihara ◽  
Kentaro Shibayama ◽  
Hasan Jilaihawi ◽  
Yuji Itabashi ◽  
Javier Berdejo ◽  
...  
Keyword(s):  
Aortic Valve ◽  
Aortic Valve Replacement ◽  
Transesophageal Echocardiography ◽  
Aortic Regurgitation ◽  
Valve Replacement ◽  
Transcatheter Aortic Valve Replacement ◽  
Color Doppler ◽  
Descending Aorta ◽  
Transcatheter Aortic Valve ◽  
Pulsed Wave Doppler

Introduction: The assessment of post-procedual aortic regurgitation (PAR) after transcatheter aortic valve replacement (TAVR) has not been validated. The purpose of this study was (1) to investigate the value of holodiastolic flow reversal (HDFR) in the descending aorta in patients with PAR after TAVR and (2) to determine which color Doppler parameters are useful for PAR grading using the intraprocedural transesophageal echocardiography (iTEE). Hypothesis: We hypothesized that HDFR in the descending aorta and any color Doppler parameters can delineate significant PAR after TAVR. Methods: Three hundred-eighty patients with severe aortic stenosis underwent TAVR with the Edwards SAPIEN valve with 131 pulsed-wave Doppler tracings from the descending aorta had assessed by iTEE. PAR was evaluated using 2D color Doppler by the cross-sectional area of the vena contracta (VCA) at the aortic annular plane, and by the longitudinal jet extent (mosaic signals, Figure A) compared to the location of the tip of the anterior mitral leaflet (AML). Significant PAR was defined as VCA of ≥10 mm2, corresponding to greater than a moderate grade. Results: In patients with any grade of PAR, pulsed-wave Doppler tracing from the descending aorta, jet extent and VCA were obtained in 100%, 80%, and 74%, respectively. All patients with consistent HDFR had significant PAR. By multivariate analysis, a consistent HDFR and jet extent beyond the tip of AML were independent predictors of significant PAR. A consistent HDFR and jet extent beyond the tip of AML predicted significant PAR with specificity of 100% and 97%, respectively. In the other hand, patients with both negative HDFR and jet extent of less than halfway to the tip of AML had no significant PAR with a 97% specificity. Conclusions: The presence of HDFR with each cardiac cycle and jet extent beyond the tip of AML are indicative of significant PAR.

Measurement and Numerical Simulation of the Velocity Profile in the Thin Film of an Impinging Water Jet

2021 ◽  
Vol 144 (3) ◽  
Author(s):  
Matthias Joppa ◽  
Mike Bermuske ◽  
Frank Rüdiger ◽  
Lars Büttner ◽  
Jochen Fröhlich ◽  
...  
Keyword(s):  
Velocity Profile ◽  
Simulation Model ◽  
Process Optimization ◽  
Low Cost ◽  
Simulation Models ◽  
Fluid Simulation ◽  
Doppler Velocity ◽  
Measurement Technology ◽  
Mean Velocity ◽  
Validation Data

Abstract Impinging circular free-surface water jets are used in challenging cooling and cleaning tasks. In order to develop simulation models for process optimization, validation data are required, which are currently not available. Therefore, the flow field of these jets is studied for the first time with the novel laser Doppler velocity profile sensor. The mean velocity field and fluctuations are measured within the stagnation and adjacent redirection region for radial coordinates up to three times the nozzle diameter. In the examined parameter range with jet velocities up to 17 m/s and nozzle diameters up to 5.2 mm, i.e., Reynolds numbers up to 69 500, thin films of a few hundred micrometers are formed, which hinder the measurement with common optical measuring systems. Based on the measurement results, a comparatively low-cost volume of fluid simulation model is developed and validated that presumes a relaminarized film flow. The profiles measured and the simulated flow show very good agreement. In the future, the simulation model provides a basis for process optimization and the innovative measurement technology used will prospectively provide further detailed insights into other flows with high velocity gradients.

Sign in / Sign up

Export Citation Format

Share Document