Improvement of transthoracic pulmonary venous flow Doppler signal with intravenous injection of sonicated albumin

OBJECTIVES: This study was performed to determine whether intravenous injection of a sonicated albumin echocardiographic contrast agent (Albunex) improved the quality of the transthoracic pulmonary venous flow Doppler signal. BACKGROUND: Previous studies have shown that transesophageal echocardiography provides pulmonary venous flow Doppler signals superior in quality to those seen with transthoracic echocardiography, which are of limited quality in up to 25% of patients. METHODS: Twenty-one patients underwent transthoracic pulsed wave Doppler examination of pulmonary venous flow before, during and after two doses of Albunex ranging from 0.08 ml/kg (low dose) to 0.22 ml/kg (high dose). In addition, five patients underwent transesophageal examination of pulmonary venous flow before and after a 0.08-ml/kg dose of Albunex. The efficacy of the contrast injection was determined using a score that graded the quality of the three components of the pulmonary venous Doppler signal from 0 to 3 (0 = no visible signal; 3 = optimal signal). RESULTS: Albunex enhanced the quality of the pulmonary venous Doppler signal from baseline (score 3.9 +/- 1.8 [mean +/- SD]) and at both low (score 5.1 +/- 2.2, p < 0.05) and high doses (score 5.6 +/- 2, p < 0.001). Transthoracic pulmonary venous flow velocities were increased, and peak flow velocity ratios were unchanged, after injection of contrast agent. The contrast-enhanced variables showed good agreement with transesophageal flow velocities. CONCLUSIONS: Albunex improves the quality of the transthoracic pulmonary venous Doppler signal, thus allowing improved accuracy of measurement. This approach appears to be effective for increasing the quality of data obtained from the transthoracic examination.