Assessment of severity of aortic regurgitation by M-mode colour Doppler flow imaging

To assess the value of measuring the aortic regurgitant jet diameter at its origin by M-mode colour Doppler imaging, 82 patients with aortic regurgitation underwent, within 72 h of each other, colour Doppler examination and angiography. After excluding one patient without colour Doppler aortic regurgitation and five with a highly eccentric regurgitant jet, we found a close relationship between the jet diameter at its origin measured by M-mode colour Doppler and the angiographic grade of aortic regurgitation (r = 0.88). A jet diameter greater than or equal to 12 mm identified severe aortic regurgitation (grade III or IV) with a sensitivity of 86.4% and a specificity of 94.4%. In 38 patients, the jet diameter correlated well with the regurgitant fraction measured by a combined haemodynamic-angiographic method (r = 0.88). A jet diameter greater than or equal to 12 mm identified a regurgitant fraction greater than or equal to 40% with a sensitivity of 88.2% and a specificity of 95.2%. This study indicates that the size of the regurgitant jet diameter at its origin measured by M-mode colour Doppler provides a simple and useful measure of the severity of aortic regurgitation. It may allow differentiation between mild or moderate and severe aortic regurgitation and evaluation of regurgitant fraction.