Contemporary approved echo contrast agents share a common approved indication of left ventricular opacification and enhancement of endocardial border delineation for the assessment of left ventricular function in patients with technically suboptimal echocardiograms (ECGs). The use of echo contrast agents with advanced imaging technologies has resulted in the conversion of many non-diagnostic ECGs to those of diagnostic quality. The use of echo contrast agents for left ventricular opacification has been shown to be particularly useful in situations in which standard echocardiographic imaging is technically the most challenging, including obesity, chronic pulmonary disease, critically ill patients on respirators, and image acquisition during stress echocardiography.
The accurate assessment of left ventricular ejection fraction is important because it provides important prognostic information in the evaluation and management of patients with cardiovascular disease. Accurate evaluation of regional and global ventricular function by echocardiography is dependent upon adequate endocardial border definition. While native tissue harmonic imaging enables better endocardial definition than standard fundamental imaging and reduces the number of patients with inadequate studies, contrast-enhanced left ventricular opacification confers additional benefits.
The use of echo contrast agents has helped to improve the accuracy of ventricular function and volume measurement by echocardiography in the assessment of left ventricular function compared with standard and fundamental imaging, and is comparable in accuracy with current gold standard techniques such as magnetic resonance imaging and radionuclide angiography. The use of echo contrast agents improves the ability to identify and grade resting wall motion abnormalities, and provides superior endocardial visualization with stress echocardiography. The use of echo contrast agents has resulted in an improvement in interobserver agreement, as well as physician confidence in qualitative and quantitative measurements.