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Limitations of color flow doppler imaging in the quantification of valvular regurgitation: Velocity of regurgitant jet, rather than volume, determines size of color doppler image

1993; Elsevier BV; Volume: 126; Issue: 1 Linguagem: Inglês

10.1016/s0002-8703(07)80025-1

1097-6744

Douglas W. Losordo, John O. Pastore, Deborah Coletta, Donna Kenny, Jeffrey M. Isner,

Atrial Fibrillation Management and Outcomes

The objective of this study was to determine the validity of estimation of regurgitant volume by visual assessment of color flow Doppler display. An experimental apparatus was designed that is capable of ejecting precise volumes of echogenic material from one chamber to another under continuous color flow Doppler monitoring. The velocity of flow was altered independently by changing either the size of the orifice through which flow occurred or the ejection rate. In this manner the differential effects of volume and velocity on the color flow Doppler image could be examined. The maximum area encompassed by the color flow Doppler pattern for each ejection was planimetered by using commercially available on-line software. In addition the reviewer in each case applied a subjective grade to the appearance of the color flow jet (1+ to 4+). Comparison was then made of the color flow Doppler appearance of equal volumes flowing at different velocities and of different volumes flowing at different velocities. In the initial series a solution of agitated hetastarch was used. When equal volumes were imaged at different velocities the higher-velocity jet appeared larger, both subjectively (3+ vs 1+) and by measuring the area encompassed in the Doppler flow profile (40.3 ± 1.8 vs 22.0 ± 1.4 cm2, p = 0.0001). Furthermore, when different volumes were imaged at different velocities, the smaller volume (3 ml vs 6 ml) appeared larger when it was flowing at higher velocity (3+ vs 2+, 40.3 ± 1.8 vs 32.4 ± 1.3 cm2, p = 0.0006). These experiments were repeated with blood, confirming the results of the initial study: When equal volumes (3 ml) were used and velocity was changed by increasing flow rate through the same orifice, the higher velocity jet appeared larger (14.8 ± .88 vs 8.5 ± .34 cm2, p = 0.0007). Additionally, a smaller volume could appear larger whether the velocity was increased by changing the orifice size (19.2 ± .83 vs 8.5 ± .34 cm2, p = 0.0007) or the rate of flow through the same orifice (13 ± .45 vs 8.5 ± .34 cm2, p = 0.0002). It is concluded that color flow Doppler images are a more accurate reflection of the velocity, rather than the volume, of regurgitant jets. Visual estimation of the severity of regurgitation based on color Doppler examination must be approached with caution.