Effective mitral regurgitant orifice area: Clinical use and pitfalls of the proximal isovelocity surface are method

Objectives. We attempted to determine the accuracy and pitfalls of calculating the mitral regurgitant orifice are with the proximal isovelocity surface are method in clinical series that included patients with valvular prolapse and eccentric jets. Background. The effective regurgitant orifice area, measure of lesion severity of mitral regurgitation, can be calculated by the proximal isovelocity surface are method, the accuracy and pitfalls of which have not been established. Methods. In 119 consecutive patients with isolated mitral regurgitation, effective regurgitant orifice are was measured by the proximal isovelocity surface are method and compared with measurements simultaneously obtained by quantitative Doppler and quantitative two-dimensional echocardiography. Results. The effective mitral regurgitant orifice are measured by the proximal isovelocity surface are method tended to be overestimated compared with that measured by quantitative Doppler and quantitative two-dimensional echocardiography (38 ± 39 vs. 36 ± 33 mm2 [p = 0.09] and 34 ± 32 mm2 [p = 0.02], respectively). Overestimation was limited to patients with prolapse (61 ± 43 vs. 56 ± 35 mm2 [p = 0.05] and 54 ± 34 mm2 [p = 0.014]) and was restricted to patients with nonoptimal flow convergence (n = 7; 137 ± 35 vs. 84 ± 34 mm2 [p = 0.002] and 79 ± 33 mm2 [p = 0.002]). In patients with optimal flow convergence (n = 112), excellent correlations with both reference methods were obtained (r = 0.97, SEE 6 mm2 and r = 0.97, SEE 7 mm2, p < 0.0001). Conclusions. In calculating the mitral effective regurgitant orifice are with the proximal isovelocity surface are method, the observed pitfall (overestimation due to nonoptimal flow convergence) is rare. Otherwise, the method is reliable and can be used clinically in large numbers of patients.