Doppler-Derived Ejection Intraventricular Pressure Gradients Provide a Reliable Assessment of Left Ventricular Systolic Chamber Function

Abstract

Background-Ejection intraventricular pressure gradients are caused by the systolic force developed by the left ventricle (LV). By postprocessing color Doppler M-mode (CDMM) images, we can measure noninvasively the ejection intraventricular pressure difference (EIVPD) between the LV apex and the outflow tract. This study was designed to assess the value of Doppler-derived EIVPDs as noninvasive indices of systolic chamber function. Methods and Results-CDMM images and pressure-volume (conductance) signals were simultaneously acquired in 9 minipigs undergoing pharmacological interventions and acute ischemia. Inertial, convective, and total EIVPD curves were calculated from CDMM recordings. Peak EIVPD closely correlated with indices of systolic function based on the pressure-volume relationship: peak elastance (within-animal Rϭ0.98; between-animals Rϭ0.99), preload recruitable stroke work , and peak of the first derivative of pressure corrected for end-diastolic volume (within-animal Rϭ0.88; between-animals Rϭ0.91). The correlation of peak inertial EIVPD with these indices was also high (all RϾ0.75). Load dependence of EIVPDs was studied in another 5 animals in which consecutive beats obtained during load manipulation were analyzed. During caval occlusion (40% EDV reduction), dP/dt max , ejection fraction, and stroke volume significantly changed, whereas peak EIVPD remained constant. Aortic occlusion (40% peak LV pressure increase) significantly modified dP/dt max , ejection fraction, and stroke volume; a nearly significant trend toward decreasing peak EIVPD was observed (Pϭ0.06), whereas inertial EIVPD was unchanged (Pϭ0.6). EIVPD beat-to-beat and interobserver variabilities were 2Ϯ12% and 5Ϯ11%, respectively. Conclusions-Doppler-derived

Ultrasound Vector Flow Imaging: I: Sequential Systems

“…Time-resolved alongstreamline pressure gradients can also be estimated in the left ventricular chamber by adapting Euler's equation to Doppler velocities measured by color M-mode. Intraventricular peak pressure gradients are potential early markers of the cardiac function [171], [172]. Two-dimensional relative pressure mapping derived from VFI was first described in the left ventricle using the Doppler-based VFM technique [173].…”

Unsupervised dealiasing and denoising of color-Doppler data

“…2): in the classical red-blue colormap, colorencoded velocities wrap around so that color information turns from red to blue or vice versa. Recent quantitative tools with potentially high clinical interest rely upon the velocity field measured by color Doppler (Yotti et al, 2005;Arigovindan et al, 2007;Edvardsen et al, 2005). Recovering aliased velocities is a sine qua non for these techniques to afford reliable information.…”

“…Because the DCT algorithms are easily parallelizable, the DeAN could be largely sped up by the use of graphics processing units (GPU) and implemented in ultrasound scanners to obtain real-time smoothed and denoised Doppler fields. The DeAN can thus offer the possibility of better studying some recently investigated aspects of blood flow dynamics, such as intracardiac pressure gradients (Yotti et al, 2005) and vortex dynamics Uejima et al, 2010).…”

“…To cite a few examples, ultrasound color flow imaging is used to detect vascular stenoses, appraise the flow patterns in the heart cavities and follow up the development of aneurysms. Using this method, it is also possible to get quantitative measurements such as mitral regurgitant flow rate (Grayburn, 2008), left ventricular flow propagation velocity (Lester et al, 2008) or intra-ventricular pressure gradients (Yotti et al, 2005). Recently, there has also been a revival of interest in vectorial flow field reconstruction from color Doppler imaging using a multibeam approach (Arigovindan et al, 2007).…”

1135 Exploring pressure gradients measured in the left heart during diastole

“…Measurements of these gradients can provide insight into diastolic function, although the physical significance of the spatial variation of the pressure gradients is still not well understood. In the current literature ΔP is typically measured within the left ventricle [1][2][3]. This approach neglects the role of the atrium in filling, which can become increasingly important for patients with diastolic dysfunction.…”