Direct measurement of multiple vena contracta areas for assessing the severity of mitral regurgitation using 3D TEE

The aim of this study was to determine whether direct measurement of multiple-jet vena contracta (VC) areas by real-time 3-dimensional (3D) transesophageal echocardiography is an accurate method for measuring the severity of mitral regurgitation (MR) in patients with multiple MR jets.

Because of the conflicting requirements of Doppler and imaging physics, measuring VC using 2-dimensional (2D) echocardiography is a difficult procedure for assessing MR severity. A real-time 3D echocardiographic measurement of the VC area has been validated in a single jet of MR, but the applicability of this method for multiple jets is unknown.

Two-dimensional and 3D transesophageal echocardiography was performed in 60 patients with multiple functional MR jets. MR severity was assessed quantitatively using the effective regurgitant orifice area derived from 3D left ventricular volume and thermodilution data (EROAstd). Manual tracings of multiple 3D VC areas in a cross-sectional plane through the VC were obtained, and the sum of the areas was compared using EROAstd. Similarly, 2D measurement of VC diameter was obtained from a 2D transesophageal echocardiographic view to optimize the largest legion size in each jet. All VC diameters were summed and compared with EROAstd.

The correlation of the sum of the multiple 3D VC areas with EROAstd (r = 0.90, p < 0.01) was higher than that of the sum of the multiple 2D VC diameters (r = 0.56, p < 0.01), particularly with MR degrees greater than mild (r = 0.80, p < 0.01 vs. r = 0.05, p = 0.81) and in cases of 3 or more regurgitant jets (r = 0.91, p < 0.01 vs. r = 0.46, p = 0.05).

Direct measurement of multiple VC areas using 3D transesophageal echocardiography allows for assessing MR severity in patients with multiple jets, particularly for MR degrees greater than mild and in cases of more than 2 jets, for which geometric assumptions may be challenging.