Purpose: Live three-dimensional echocardiography (3D echo) improves the comprehensive approach of various cardiac pathologies. We sought to evaluate the potential interest of live 3D color-flow Doppler in the assessment of mitral regurgitant (MR) jets.
Methods: One hundred patients (59 ± 17 years, 49 males) presenting with at least mild MR were prospectively studied using 2D echocardiography and live 3D echo (Sonos Agilent 7500, Philips). Live 3D echo data were analyzed in a blind fashion 8.3 ± 6.9 months after acquisition and subsequently compared with 2D data. The convergence zone and the vena contracta sizes and shapes, the jet origin and the number of jets, the left atrial jet direction and extent were analyzed.
Results: Mitral regurgitation was grade 1-2 in 33 % of patients and grade 3-4 in 67 % of patients using 2D echocardiography. For each patient 5.2 ± 2.5 3D volumes were acquired, including 2.1 ± 1.1 color-flow volumes. Mean time for analysis was 7.0 ± 2.9 min including 2.4 ± 1.1 min for 3D color-flow doppler analysis. The quality of color-flow doppler images was considered as good in 30 % of patients, as fair in 49 %, and poor in 21 %. The color-flow Doppler was analyzable in 95 % of patients. Using Kappa statistics, 3D color-flow doppler demonstrated a good agreement with 2D echo in the localization of the main jet origin (Kappa: 0.85 ; 0.75-0.95). The number of jets per patient (1 to 4) was higher with 3D echo compared with 2D echo (1.36 ± 0.70 vs 1.21 ± 0.48, p = 0.042). The main jet origin was lateral in 5 % of patients, central in 62 %, medial in 5 %. The main axis of MR jet was considered as central in 28 %, moderately eccentric in 30 %, and eccentric in 42 % of patients. Live 3D color-flow Doppler greatly improves the MR analysis, demonstrating a non hemispheric shape of convergence zone and a non circular vena contracta in up to 47 % of patients. The direct measurement of vena contracta size using 3D tools demonstrated a close correlation with the quantitative Doppler method (r = 0.91, p < 0.0001), while the PISA method underestimated MR, particularly in patients with very stretched jets. The subsequent discrepancy in MR quantification (between the PISA and the quantitative Doppler methods using 2D echo) had a clinical impact in 16 % of patients (ERO 0.13 ± 0.05 vs 0.33 ± 010 cm2).
Conclusion: Real-time 3D color-flow Doppler can be considered as a simple and useful tool to assess mitral jets allowing a semi-quantitative approach of MR, providing important additional information compared and guiding the choice of the MR quantification method.
© 2007 Elsevier Masson SAS. Tous droits réservés.