Real-Time 3D Transesophageal Echocardiography for the Evaluation of Rheumatic Mitral Stenosis

ObjectivesThe aims of this study were: 1) to assess the feasibility and reliability of performing mitral valve area (MVA) measurements in patients with rheumatic mitral valve stenosis (RhMS) using real-time 3-dimensional transesophageal echocardiography (3DTEE) planimetry (MVA3D); 2) to compare MVA3D with conventional techniques: 2-dimensional (2D) planimetry (MVA2D), pressure half-time (MVAPHT), and continuity equation (MVACON); and 3) to evaluate the degree of mitral commissural fusion.Background3DTEE is a novel technique that provides excellent image quality of the mitral valve. Real-time 3DTEE is a relatively recent enhancement of this technique. To date, there have been no feasibility studies investigating the utility of real-time 3DTEE in the assessment of RhMS.MethodsForty-three consecutive patients referred for echocardiographic evaluation of RhMS and suitability for percutaneous mitral valvuloplasty were assessed using 2D transthoracic echocardiography and real-time 3DTEE. MVA3D, MVA2D, MVAPHT, MVACON, and the degree of commissural fusion were evaluated.ResultsMVA3D assessment was possible in 41 patients (95%). MVA3D measurements were significantly lower compared with MVA2D (mean difference: −0.16 ± 0.22; n = 25, p < 0.005) and MVAPHT (mean difference: −0.23 ± 0.28 cm2; n = 39, p < 0.0001) but marginally greater than MVACON (mean difference: 0.05 ± 0.22 cm2; n = 24, p = 0.82). MVA3D demonstrated best agreement with MVACON (intraclass correlation coefficient [ICC] 0.83), followed by MVA2D (ICC 0.79) and MVAPHT (ICC 0.58). Interobserver and intraobserver agreement was excellent for MVA3D, with ICCs of 0.93 and 0.96, respectively. Excellent commissural evaluation was possible in all patients using 3DTEE. Compared with 3DTEE, underestimation of the degree of commissural fusion using 2D transthoracic echocardiography was observed in 19%, with weak agreement between methods (κ < 0.4).ConclusionsMVA planimetry is feasible in the majority of patients with RhMS using 3DTEE, with excellent reproducibility, and compares favorably with established methods. Three-dimensional transesophageal echocardiography allows excellent assessment of commissural fusion.