An In Vitro Study and Initial Clinical Observations

convergence zone. Methods and Results. In an in vitro study, we showed the feasibility and the accuracy of calculating effective ROA by the proximal flow convergence method throughout a range of driving pressures. The calculated and true ROA showed an excellent correlation with r=.992, AROA= -1.4±2.9 mm2. We then applied this concept clinically in 77 patients with mitral regurgitation and showed a very good correlation between effective ROA calculated by the proximal flow convergence method and calculated by the Doppler echocardiographic method: r=.95, AROA=-0.2±3.9 mm2. The ROA also correlated very well with Doppler echocardiographic-derived regurgitant stroke volume (r=.93) and regurgitant fraction (r=.82). In a subgroup of 20 patients who underwent invasive evaluation, the calculated effective ROA also correlated well with the angiographic grade of mitral regurgitation (p=.81). Conclusions. We conclude that effective ROA represents unique information on the severity of a regurgitant lesion and can easily be calculated by the proximal flow convergence method. This new parameter should enhance our understanding and improve the serial assessment of valvular regurgitation. (Circulation. 1993;88:1150-1156.)