Kurzfassung. Mittels Computational Fluid Dynamics (CFD) wurden quantitative Strömungssimulationen bei Mitralklappeninsuffizienzen erstellt. Die individuelle Geometrie des menschlichen valvulären Apparats wurde dabei volumetrischen Bilddaten entnommen. Das resultierende dynamische 3D-Flussfeld wurde als Basis für eine nachfolgende FarbDoppler-Simulation verwendet. Dadurch lässt sich der Einfluss...

BACKGROUND Noninvasive quantification of regurgitation is limited because Doppler measures velocity, not flow. Because backscattered Doppler power is proportional to sonified blood volume, power times velocity should be proportional to flow rate. Early studies, however, suggested that this held only for laminar flow, not for regurgitant jets, in which turbulence and fluid entrainment augment sc...

AIMS We sought to demonstrate geometric changes in the tricuspid valve (TV) apparatus after tricuspid annuloplasty (TAP) and to identify predictors of residual tricuspid regurgitation (TR) in patients with functional TR using real-time three-dimensional echocardiography (RT3DE). METHODS AND RESULTS RT3DE and two-dimensional colour Doppler echocardiography were performed in 59 consecutive pati...

BACKGROUND No gold standard currently exists for quantification of mitral regurgitation (MR) severity. Classification by echocardiography is based on integrative criteria using color and spectral Doppler and anatomic measurements. We hypothesized that a simple Doppler left ventricular early inflow-outflow index (LVEIO), based on flow velocity into the left ventricle (LV) in diastole and ejected...

BACKGROUND Quantitation of aortic regurgitation (AR) using two-dimensional (2D) echocardiography, including vena contracta width (VCW) measurement, is still challenging. Three-dimensional (3D) echocardiography can directly measure the vena contracta area (VCA), regardless of the rheological characteristics. We intended to assess the possibility of 3D vena contracta area (3DVCA) as well as 2D ve...

Background Today, there is no accepted approach to evaluate tricuspid regurgitation (TR) using cardiovascular magnetic resonance (CMR). Contrary to 4-chamber imaging planes, which often do not show the entire regurgitant jet, these jets are readily visualized in short-axis views in the right atrium (RA). We hypothesized that the size and signal intensity (SI) of the cross-sectional jet area in ...

It is to be investigated and verified that vena contracta width (VCW) obtained from color Doppler images and effective regurgitant orifice area (EROA) obtained from the VCW is capable of quantifying the severity of mitral regurgitation (MR). A mathematical expression has been developed between VCW and EROA. Vena contracta width is an efficient method for grading the severity of MR, but it is ve...

Abstract: A detailed numerical study of turbulent flow through a micro-orifice is presented in this work. The flow becomes turbulent due to the orifice at the considered Reynolds numbers (∼104). The obtained flow rates are in good agreement with the experimental measurements. The discharge coefficient and the pressure loss are presented for two input pressures. The laminar stress and the genera...

BACKGROUND Accurate quantification of mitral regurgitation (MR) is important for patient treatment and prognosis. Three-dimensional echocardiography allows for the direct measure of the regurgitant orifice area (ROA) by 3D-guided planimetry of the vena contracta area (VCA). We aimed to (1) establish 3D VCA ranges and cutoff values for MR grading, using the American Society of Echocardiography-r...