Factors influencing pulmonary venous flow velocity patterns in mitral regurgitation: an in vitro study.

Objectives: The aim of this study was to investigate factors affecting pulmonary venous flow patterns in mitral regurgitation.

Background: Although pulmonary venous flow velocity patterns have been reported to be helpful in assessing the severity of mitral regurgitation, the influence of regurgitant jet direction, pulmonary venous location and left atrial pressures on pulmonary venous flow patterns has yet to be clarified.

Methods: The mitral regurgitant jet was produced by a pulsatile piston pump at 10, 30 and 40 ml/beat through a circular orifice, whereas the pulmonary venous flow was driven by gravity.

Dynamic change in mitral regurgitant orifice area: comparison of color Doppler echocardiographic and electromagnetic flowmeter-based methods in a chronic animal model.

Objectives: The aim of the present study was to investigate dynamic changes in the mitral regurgitant orifice using electromagnetic flow probes and flowmeters and the color Doppler flow convergence method.

Background: Methods for determining mitral regurgitant orifice areas have been described using flow convergence imaging with a hemispheric isovelocity surface assumption. However, the shape of flow convergence isovelocity surfaces depends on many factors that change during regurgitation.

Effects of pulmonary venous flow direction on mitral regurgitation jet area as imaged by color Doppler flow mapping. An in vitro study.

Background: Although the effects of adjacent walls and left atrial pressure on mitral regurgitation (MR) jet area imaged by color Doppler have been examined, few data exist regarding the influence of pulmonary venous (PV) filling flow on regurgitant jets. Therefore, we designed a left atrial model to examine the relation between PV flow direction and MR jet area.

Methods And Results: The left atrial chamber (7.

Color Doppler regurgitant jet area for evaluating eccentric mitral regurgitation: an animal study with quantified mitral regurgitation.

Objectives: The purpose of the present study was to rigorously evaluate the accuracy of the color Doppler jet area planimetry method for quantifying chronic mitral regurgitation.

Background: Although the color Doppler jet area has been widely used clinically for evaluating the severity of mitral regurgitation, there have been no studies comparing the color jet area with a strictly quantifiable reference standard for determining regurgitant volume.

Methods: In six sheep with surgically produced chronic mitral regurgitation, 24 hemodynamically different states were obtained.

Evaluation of mitral regurgitation using a digitally determined color Doppler flow convergence 'centerline' acceleration method. Studies in an animal model with quantified mitral regurgitation.

Background: The imaging and measurement of the proximal flow convergence region in the left ventricle have been reported to be useful for identifying the site of mitral regurgitation (MR) and for evaluating its severity. However, the application of this method has not gained general acceptance. There have been few in vivo studies with quantified reference standards for determining regurgitant volume, and those that have been reported used spectral Doppler standards and/or nonsimultaneously performed contrast ventriculography.