[Quantification of mitral regurgitant stroke volume by the proximal isovelocity surface area method]

Although color Doppler flow mapping has been used to quantitate the severity of mitral regurgitation, this approach has various limitations. Doppler color flow mapping of a proximal isovelocity surface area (PISA), defined by a blue-red aliasing interface, has been shown in vitro to be accurate for estimating volume flow rate across an orifice. Volume flow rate can be calculated as PISA x aliasing velocity. To evaluate the clinical applicability of the PISA method, we compared the regurgitant stroke volume estimated by the PISA method with the conventional pulsed wave Doppler method in 18 patients with mitral regurgitation. The mean systolic aliasing radius was calculated from color overlayed M-mode (Q/M-mode) images. The mitral regurgitant stroke volume calculated by the PISA method correlated well with that calculated by the pulsed Doppler method (r = 0.89, SEE = 6.0 ml). Thus, the color Doppler PISA method can be applicable to calculating the regurgitant volume in patients with mitral regurgitation.