Volumetric measurement of the anatomic regurgitant orifice area in mitral regurgitation: Comparison with two-dimensional flow convergence analysis

Mitral effective regurgitant orifice area (EROA) using the flow convergence (FC) method is the current method of choice for quantifying the severity of mitral regurgitation (MR). However, this methodology has limitations, especially in patients with complex mitral valve (MV) pathology. The superior image quality of the transesophageal real-time 3D echocardiography (RT3D-TEE) offers an opportunity for direct visualization and 3D measurement of the anatomic regurgitant orifice area (AROA). Accordingly, we developed a 3D technique to measure AROA from RT3DE-TEE datasets and compared it with the conventional FC derived measurements of EROA. We studied 61 patients, undergoing clinically indicated TEE, with well visualized FC. ROA calculations obtained from TEE images using FC technique (EROA); and zoomed RT3DE-TEE acquisitions using prototype software for direct 3D orifice area measurements (AROA) correlated well (r=0.81) and showed only a non-significant bias (0.05 cm²). In conclusion, visualization of the true, anatomic MV orifice area from RT3DE-TEE images is feasible in most patients. 3D volumetric analysis of AROA may become a useful alternative to quantify MR in patients in whom EROA measurement by FC technique is challenging.