Transesophageal echocardiographic assessment of mitral regurgitation using the proximal flow convergence method

Objectives: Transesophageal echocardiography (TEE) is best suited for the assessment of mitral valve regurgitation before cardiac surgery and accurate estimation of severity allows to recognize patients at risk for development of long term post-operative left ventricular dysfunction. The purpose of this study was to determine the value of direct calculation of effective regurgitant orifice (ERO) by TEE in comparison with angiography. Methods: We studied 28 patients (pts) with chronic MR who underwent cardiac catheterization within 20 days from TEE procedure. The maximun regurgitation flow (MRF) was established by the method of proximal flow convergence (MRF = 2 x p-greco x radius2 x Nysquist limit). Usual angiographic semi-quantitative grading of MR (1-4) was determined. Pts were divided into four groups according to the angiographic grade of MR. Results: MRF was calculated in 27 pts (feasibility 96%). Echocardiographic values estimated by TEE closely correlated with angiographic data (r = 0.81, p < 0.001). ERO identified pts with severe mitral regurgitation (0.45-0.97 cm2) with 0.45 cm2 as cut-off value. Pts with trivial MR were also detected by ERO (0.11-0.07 cm2) with 0.11 cm2 as cut-off value. Overlapping values were found in pts with MR of intermediate severity. Conclusions: TEE estimation of MR severity by the proximal flow convergence method is accurate and feasible showing a good correlation with angiographic findings.