Clinical usefulness of intravenous Albunex for the Doppler assessment of aortic stenosis

Optimal Doppler recordings of stenotic aortic how are not always easy to ob tain. Therefore, the present study investigated how useful intravenous Albu nex injections were for improving the Doppler assessment of pressure gradie nts for aortic stenosis in 20 consecutive patients who underwent Doppler an d left-heart catheterization studies within a 1-week period. Continuous-wav e Doppler echocardiography was performed using both a 2.5 MHz duplex and a 1.9 MHz independent transducer before and after Albunex injections. The max imum and mean pressure gradients were calculated from the highest Doppler v elocity tracings using the simplified Bernoulli equation. Pullback catheter ization pressure tracings from the left ventricle to the ascending aorta we re superimposed for determination of the maximum instantaneous and mean pre ssure gradients. The Doppler-derived peak and mean pressure gradients showe d significant underestimation compared with the catheterization gradients ( 23+/-17 mmHg and 11+/-7 mmHg, respectively). However, this underestimation disappeared with Albunex injection (-2+/-7 mmHg and -1+/-4 mmHg, respective ly). Although the Doppler-derived instantaneous and mean pressure gradients correlated well with the catheterization gradients (r=0.909 and r=0.879, r espectively), they became much closer with Albunex (r=0.987 and r=0.963, re spectively). The improvements in the Doppler-derived peak pressure gradient s were significant from an apical window (n=12, 84-120 mmHg, p<0.001), but less so from non-apical windows (n=8, 84-91 mmHg, p=0.0146). Accordingly, A lbunex is most useful for Doppler recordings of stenotic aortic how availab le from the apical window, but not less so from other acoustic windows.