Abstract 15980: Comparison of an Automated Method for Quantification of Mitral Regurgitation Flow Using 3 Dimensional Color Doppler Imaging of Proximal Velocities With 2 Dimensional Echocardiographic Methods
Background: Assessment of mitral regurgitation (MR) severity by echocardiography is challenging. Quantitative measures such as proximal isovelocity surface area (PISA) and effective regurgitant orifice area (EROA) are subject to inter-observer variability and time-consuming to perform. Automated measurement of the flow convergence zone could improve MR quantification.
Aim: To compare a novel automated 3D echo method for assessing MR severity with standard 2D measurements
Methods: Patients with a range of severities and etiologies of MR having a transesophageal echocardiogram (TEE) were examined. Severity of MR was assessed from 2D TEE images as EROA and RV by PISA. 3D EROA and RV were calculated from four and six beat full volume 3D color Doppler acquisitions using a novel computer algorithm that incorporated non-linear curve fitting of a hemispherical flow model to the Doppler signals observed in the flow convergence zone (see figure).
Results: Twenty four patients with MR were examined (mean age 76.3± 9.4; 37.5% females). The mean 2D EROA was 0.20 ± 0.14 cm2 and the mean 2D RV was 36.31 ± 24.51 cm3. Mean 3D EROA was 0.24 ± 0.17 cm2 and mean 3D RV was 41.33 ± 25.41 cm3. There was excellent correlation between the 2D and 3D EROA (R = 0.92) and RV (R = 0.76). Bland-Altman analysis revealed greater inter-observer variability for 2D EROA (Mean bias=0.08, 1.96 SD -0.03 to 0.19; CC=0.935, CI 0.741 to 0.985, p=0.0001) and 2D RV (Mean bias=14.3, 1.96 SD -10.5 to 39; CC=0.818, CI 0.388 to 0.955, p=0.0039) than for 3D EROA (Mean bias=-0.02, 1.96 SD -0.06 to 0.03; CC=0.996, CI 0.978 to 0.999, p<0.0001) and 3D RV (Mean bias=-6.1, 1.96 SD -23.5 to 11.4; CC=0.992, CI 0.960 to 0.998, p<0.0001).
Conclusion: Direct automated measurement of PISA region for EROA calculation using real-time 3D color Doppler echocardiography is feasible with a high correlation to current 2D EROA methods but with less variability. This novel automated method may offer a time efficient alternative for quantification of MR flow.
- © 2013 by American Heart Association, Inc.