Immediate post-procedural reduction in MR or, conversely the degree of residual MR, has been shown to be a predictive factor of long-term improvement in MR, LV and LA reverse remodeling, and survival. Current assessment of MR reduction post-MitraClip relies on a combination of indirect hemodynamic parameters, such as LA pressure and 2-D Echo parameters, which are semi-quantitative at best. Therefore, a rapid and accurate quantitative method to assess the degree of residual MR is of great need to complement other invasive and indirect/qualitative echo parameters. This will not only improve the reliability and reproducibility of residual MR assessment post-Mitraclip, but will also provide an objective index to define successful procedural outcomes. The latter may potentially help in decision making for the placement of additional clips to further reduce MR. Of the quantitative color Doppler parameters used to measure the degree of MR, regurgitant volume/fraction (RV/RF) is probably the most optimal index. The Mitra-clip has been shown to distort data from the flow convergence (PISA) method, resulting in complicated and unreliable assessments of MR. Similarly, vena contracta (VC) is also distorted by the Mitra-Clip, which can lead to unreliable and unreproducible measures of MR. It has been previously shown that real-time volume color flow Doppler (RT-VCFD) trans-thoracic echocardiography (TTE) is useful to quantify RV/RF and comparable to CMR. Since 3-D transesophageal echocardiography is commonly used for Mitra-Clip assessment, the same principle can be applied to RT-VCFD TEE. The preliminary experience with this approach has shown promise.