To evaluate usefulness and limitations of proximal jet dimensions for the quantitation of valvular regurgitation, fluid jets were created in a pulsatile flow model, and proximal jet width and cross-sectional area were measured by means of color Doppler flow imaging. When circular orifices with diameters from 1 to 6 mm were studied, jet width and cross-sectional jet area measured as close as possible to the orifice were directly related to the orifice diameter (r = 0.97; standard error of the estimate, 0.4 mm; y = 0.5 + 0.97x) and the orifice area (r = 0.97; standard error of the estimate, 5.7 mm2; y = 0.22 + 2.47x), respectively. No significant dependence on flow rate or pressure gradient was found for these measurements. Jet width was measured with color M-mode Doppler by use of the smallest sample volume size (1 mm) and was slightly greater than the orifice diameter (4.2 +/- 1.7 mm versus 3.8 +/- 1.7 mm). However, cross-sectional areas were approximately fourfold the orifice areas, on average (52.5 +/- 24.6 mm2 versus 12.3 +/- 9.7 mm2), with a range of twelvefold (smallest orifice) to threefold (largest orifice). When the sample volume size was reduced from 2.4 to 1.0 mm, color areas decreased by 25.6 +/- 6.0%. Slit-shaped orifices were studied with two different orientations of the slit-parallel and perpendicular to the ultrasound beam: Color M-mode measurements were again slightly greater than length and width of the slit, but cross-sectional areas were substantially larger than the orifice areas and increased between 44% and 115% when changing the orientation of the slit from perpendicular to parallel. This, again, reflected problems with lateral resolution. When cross-sectional areas were measured at increasing distances from the orifice, the cross-sectional jet area increased significantly within a few millimeters. This increase was greater with higher gradients and smaller orifice sizes. In case of a small orifice (2 mm) and a high gradient (130 to 160 mm Hg), increase in area was as great as 122% within a distance of only 5 mm. Thus, proximal jet width and cross-sectional area were directly related to the orifice size, which could be a valuable parameter for the evaluation of valvular regurgitation. Measurements of jet width by color M-mode seemed to be most accurate but are limited by the fact that in vivo valvular defects may be irregular rather than of circular shape.(ABSTRACT TRUNCATED AT 400 WORDS)

Aortic Valve Insufficiency↗

PubMedDate not supplied

Value of three-dimensional echocardiography as an adjunct to conventional transesophageal echocardiography.

Three-dimensional imaging of cardiac structures could enhance the functional understanding and the interpretation of pathologies. Limited processing capabilities, relocation problems and inadequate two-dimensional image quality have previously limited its applicability. Recently, an integrated echocardiographic computerized tomography unit (echo-CT) which uses a transesophageal approach has been developed. This system is capable of sampling and processing multiple echocardiographic images and, thus, provides three-dimensional views. To evaluate the feasibility and potential of this technique, we studied 69 patients with various cardiac disorders. All but 3 patients (96%) tolerated the procedure well allowing at least one scan to be performed. No complications were encountered. The indication for echo-CT included coronary artery disease (n = 4), mitral valve disease (n = 18), suspected arterial embolism (n = 19), masses (n = 8), congenital malformation (n = 10), postcardiac surgery (n = 8), aortic aneurysm (n = 1) and suspected left-to-right shunt (n = 1). Conventional transesophageal echocardiography revealed a pathology in 45 patients. Of these pathologies, 37 (82%) could be reconstructed and displayed in three-dimensional views. Three-dimensional imaging provided an improved spatial understanding of the pathology in 21 cases (39%). Echo-CT was especially valuable in diseases of the mitral value (i.e. mitral valve prolapse, flail leaflets, mitral stenosis) where it had the potential to delineate the location, type and morphology of defects. In conclusion, three-dimensional transesophageal imaging enhances image interpretation and understanding. This could be of value in complex morphologies and cardiac disorders in which surgical repair is attempted.

Adult↗