Improved reliability for echocardiographic measurement of left ventricular volume using harmonic power imaging mode combined with contrast agent.

Harmonic power imaging (HPI) is a new echocardiographic modality that enhances the detection of contrast agents in the left ventricle. The endocardium can be delineated by conventional echocardiography using ultrasound contrast agents, although the images tend to be faint. The present study was designed to assess left ventricular volume using HPI after intravenous injection of the contrast agent Levovist (Schering SA, Berlin, Germany) in 25 unselected patients. End-diastolic volume, end-systolic volume, and ejection fraction were determined for each patient with angiography and with 4 different ultrasound modalities: (1) conventional mode without contrast, (2) contrast conventional mode, (3) contrast harmonic intermittent imaging mode, and (4) contrast triggered HPI. The use of HPI improved correlations between the echographic and angiographic measurements for all parameters as well as precision and bias determined by Bland and Altman analysis. The relative errors for interobserver variability were also lower with HPI. This study demonstrates that echocardiographic determination of left ventricular volumes and ejection fraction is more accurate and reproducible using HPI combined with Levovist.