Clinical value of parameters derived by the application of the proximal isovelocity surface area method in the assessment of mitral regurgitation

Abstract To determine the clinical value of several parameters derived by application of the proximal isovelocity surface area method in the assessment of mitral regurgitation (MR), 28 consecutive patients with angiographic diagnosis of MR underwent color Doppler echocardiography within 48 h of cardiac catheterization. Aliasing velocities ( V N ) were baseline-shifted to 25 cm/s and the maximal radius ( R ) was measured from the first aliasing boundary to the tips of the mitral valve. By continuity, the regurgitant orifice area ( ROA ) and regurgitant stroke volume ( RSV PISA ) were obtained. We have related them to the angiographic grade, and with determination of the regurgitant stroke volume ( RSV DE ) and the regurgitant fraction ( RF ), we calculated the volume of the transmitral flow according to Fisher's method. Results: RSV DE correlated well with RSV PISA ( r =0.98). A clear relation existed between the isovelocity radius and the RSV DE and RF ( r =0.95 and 0.88, respectively). A radius of 8 mm or more was identified well with an RSV DE of 40 cm 3 or more (sensitivity: 100%, specificity: 95%) and an RF of 35% or more (sensitivity: 88%, specificity: 94%). The ROA was closely related to the RSV DE and RF , with r =0.92 and 0.88, respectively. An ROA of 20 mm 2 or more identified well patients with RSV DE values of 40 cm 3 or more and RF values of 35% or more. The radius, RSV PISA and ROA were closely related to the angiographic grade of MR ( r =0.91, 0.83 and 0.92, respectively). A radius of 7 mm or more identified patients with grade III or IV of regurgitation (sensitivity: 82%, specificity: 94%), while an ROA of 15 mm 2 or more discriminated well significant regurgitation (sensitivity: 91%, specificity: 94%). Conclusions: Parameters derived by application of the proximal isovelocity surface area method provide quantitative information that can be helpful in predicting the severity of mitral regurgitation noninvasively.