A lung-crossing contrast agent, sonicated albumin (Albunex), has been reported to enhance left-sided Doppler signals in patients with native valvular diseases. The purpose of this study was to clarify the ability of Albunex to enhance transvalvular Doppler signals in patients with prosthetic aortic valves. Forty-five consecutive patients were studied after they underwent aortic valve replacement. Transvalvular flow signals were recorded from the apical long-axis view with the use of continuous-wave Doppler echocardiography before and after intravenous injection of Albunex (0.04 to 0.08 ml/kg). Continuous-wave Doppler signal quality was graded as follows: 1, none; 2, poor; 3, suboptimal; and 4, optimal.
Results: Grade 4 continuous-wave Doppler signal could be detected in 64% of the cases (29 of 45). After contrast injection, continuous-wave Doppler signal quality improved in all, and grade 4 continuous-wave Doppler signal could be detected in 93% (0.04 ml/kg) and 100% (0.08 ml/kg), respectively. The transvalvular maximal velocities derived from contrast-enhanced, continuous-wave Doppler signals were well correlated with the highest available unenhanced. Doppler maximal velocities (y = 0.90x + 0.27, r = 0.93, p < 0.01, standard error of estimate = 0.08 m/sec).
Conclusion: Intravenous Albunex injection improves transvalvular continuous-wave Doppler signal intensity in patients with prosthetic aortic valves.