Quantification Of Mitral Stenosis And Mitral Regurgitation Proximal Isovelocity Surface Area Method With Real-Time Three-Dimensional Color Doppler Echocardiography

Objectives:We attempted to determine the most suitable Nyquist velocity for applying the three-dimensional proximal isovelocity surface area (3D PISA) to calculate mitral valve area (MVA) in patients with mitral stenosis.Methods:We studied20patients with MS by single-beat three-dimensional color Doppler echocardiography. The MVA was measured by the methods of planimetry (MVAp1), two-dimensional (2D) PISA (MVA2D PISA) and3d PISA (MVA3D PISA). MVAp1was used as reference methods. At the Nyquist velocities of32,26and19cm/s, the differences between MVAaDPISA. MVA3D PISA and MVAp1were analyzed; and then we analyzed the correlation between MVA2D PISA. MVA3D PISA and MVAp1respectively. Results:The aliasing velocity influenced the MVA using3D PISA method, with actual differences from-0.07cm2at the aliasing velocity of19cm/s to-0.71cm2at the aliasing velocity of32cm/s when compared with the mitral valve area obtained using2D planimetry. The3D PISA method provided more accurate estimation of MVA at the Nyquist velocity of19cm/s when compared with planimetry. The MVA using3D PISA had the best agreement with MVAp1. Conclusions:The3D PISA method provided the most accurate estimation of MVA at the Nyquist velocity of19cm/s, which provided a new method to calculate mitral valve area with mitral stenosis. Objectives:We attempted to determine the most suitable Nyquist limit for applying the three-dimensional proximal isovelocity surface area (3D PISA) to quantify mitral regurgitation (MR).Methods:We studied24patients,12with mitral valve prolapse,8with rheumatic heart disease and4with functional MR by single-beat three-dimensional color Doppler echocardiography. The effective regurgitant orifice area (EROA) and regurgitant volume were measured by the methods of two-dimensional (2D) PISA and3D PISA. Quantification of MR with Doppler volume flow at2sites was used as reference method. At the aliasing velocities of55,43,37,28andl8cm/s, the differences of EROA between3D PISA method and Doppler volume flow at2sites were analyzed.Results:EROA was progressively underestimated with increasing Nyquist limit from28cm/s. The actual and percent differences noted between the EROA by3D PISA method and Doppler volume flow at2sites were0.06±0.06cm2and9±8%at the Nyquist limit of28cm/s. At the Nyquist limit of28cm/s, the EROA calculated by the3D PISA method showed better correlations with the prviously reference method than that calculated by the2D PISA method.Conclusions:The3D PISA method provided the more accurate estimation of EROA at the Nyquist limit of28cm/s, which provided a new method to calculate MR.