Amplitude-weighted mean velocity: Clinical utilization for quantitation of mitral regurgitation

Abstract

The amplitude-weighted mean velocity-calculated regurgitant fraction is gain independent, whereas the aortic and mitral integrals are gain dependent. Compared with Doppler and two-dimensional echocardiography, it shows more scattering of values in patients without regurgitation, but the methods correlate significantly in patients with mitral regurgitation. Amplitude-weighted mean velocity can be used as a simple adjunctive tool for comprehensive, noninvasive quantitation of mitral regurgitation.

Broad-beam spectral Doppler sonification of the vena contracta using matrix-array technology

“…Previous studies using standard one-dimensional phasedarray transducer designs for Doppler power analysis were limited by a relatively narrow Doppler sample volume and therefore incomplete capture of regurgitant flow Doppler power and velocity (11,18,(31)(32)(33)(34). Experimental approaches to broaden sonification by annular array transducer design were limited to the non-imaging Doppler mode only and therefore difficult to apply in practice (17,21,35).…”

“…Experimental approaches to broaden sonification by annular array transducer design were limited to the non-imaging Doppler mode only and therefore difficult to apply in practice (17,21,35). Previous investigators aiming to measure flow through broader conduits (32,34) or fully opening heart valves (31,36,37) corrected the amplitude-weighted or power-weighted mean velocity from the sonified portion of the entire flow CSA based on a separately measured flow CSA (32,33) or simply determined a flow volume fraction (31,34,36,37); these flow estimates were inherently limited by incomplete flow sonification (31,33,34). The current approach addresses the more readily achievable goal of sonifying the regurgitant CSA, as opposed to the entire mitral or aortic annular areas.…”