Effective regurgitant orifice area: A noninvasive Doppler development of an old hemodynamic concept

Objectives. The purpose of this study was to determine the feasibility, relation to other methods and significance of the effective regurgitant orifice area measurement. Background. Assessment of the severity of valvular regurgitation (effective regurgitant orifice area) has not been implemented in clinical practice but can be made by Doppler echocardiography. Methods. Effective regurgitant orifice area was calculated by Doppler echocardiography as the ratio of regurgitant volume/ regurgitant jet time-velocity integral and compared with color flow Doppler mapping, angiography, surgical classification, regurgitant fraction and variables of volume overload. Results. In 210 consecutive patients examined prospectively, feasibility improved from the early to the late experience (65% to 95%). Effective regurgitant orifice area was 28 ± 23 mm² (mean ± SD) for aortic regurgitation (32 patients), 22 ± 13 mm² for ischemic/functional mitral regurgitation (50 patients) and 41 ± 32 mm² for organic mitral regurgitation (82 patients). Significant correlations were found between effective regurgitant orifice and mitral jet area by color flow Doppler mapping (r = 0.68 and r = 0.63, p < 0.0001, respectively) and angiographic grade (r = 0.77, p = 0.0004). Effective regurgitant orifice area in surgically determined moderate and severe lesions was markedly different in mitral regurgitation (35 ± 12 and 75 ± 33 mm², respectively, p = 0.009) and in aortic regurgitation (21 ± 8 and 38 ± 5 mm², respectively, p = 0.08). Strong correlations were found between effective regurgitant orifice area and variables reflecting volume overload. A logarithmic regression was found between effective regurgitant orifice area and regurgitant fraction, underlining the complementarity of these indexes. Conclusions. Calculation of effective regurgitant orifice area is a noninvasive Doppler development of an old hemodynamic concept, allowing assessment of the lesion severity of valvular regurgitation. Feasibility is excellent with experience. Effective regurgitant orifice area is an important and clinically significant index of regurgitation severity. It brings additive information to other quantitative indexes and its measurement should be implemented in the comprehensive assessment of valvular regurgitation.