Automated quantification of aortic regurgitant volume and regurgitant fraction using the digital colour Doppler velocity profile integration method in patients with aortic regurgitation.

BACKGROUND The recently introduced automated cardiac flow measurement (ACM) technique provides a quick and an accurate automated calculation of stroke volume and cardiac output. This is obtained by spatio-temporal integration of digital Doppler velocity profile data. OBJECTIVE To evaluate the use of the ACM method in the non-invasive assessment of aortic regurgitant volume and per cent regurgitant fraction (%RF) in patients with aortic regurgitation. METHODS Aortic outflow volume and mitral inflow volume were calculated by the ACM method in 22 patients with isolated aortic regurgitation. Aortic regurgitant volume and %RF were calculated using the following equations: aortic regurgitant volume = [aortic outflow volume] - [mitral inflow volume]; %RF = [aortic regurgitant volume]/[aortic outflow volume] x 100. The results were compared with those obtained using pulsed Doppler cross sectional echocardiography (PD-2D). RESULTS Aortic regurgitant volumes measured by the ACM method showed a good correlation with the PD-2D measurements (r = 0.95, y = 0.9x + 3.9, SEE = 8.6 ml); the mean (SD) difference between the two methods was -1.5 (8.5) ml. %RF estimated by the ACM method also correlated well with the values obtained by the PD-2D method (r = 0.91, y = 0.9x + 4.9, SEE = 6.0%); the mean difference between the two methods was -1.5 (6.0)%. Total time required for aortic regurgitant volume (for one cardiac cycle) by the ACM method was significantly shorter than by the PD-2D method (130 (16) v 230 (32) s, p < 0.01). CONCLUSIONS The newly developed the ACM method is quick and accurate in the automated assessment of aortic regurgitant volume and per cent regurgitant fraction in patients with isolated aortic regurgitation.