Clinical applications of contrast echocardiography

The recent development of second-generation microbubble contrast agents that are capable of left ventricular and myocardial opacification through transpulmonary route via intravenous injection is a major new advance in diagnostic cardiac imaging. Specific current applications of these agents are: (1) enhancement of endocardial border delineation to improve evaluation of LV regional and global wall motion, volume and ejection fraction measurement and intracavitary lesion differentiation; (2) augmentation of spectral Doppler signal to assess pulmonary venous flow tracing and valvular lesions; (3) myocardial perfusion imaging for detection of viable muscle, diagnosis and management of acute and chronic coronary syndromes; and (4) use in operating room and during coronary interventions. Future prospects for clinical applications will include quantification of myocardial perfusion, direct visualization of intramyocardial arteries with measurement of flow reserve, merges mapping with 3-D image and tissue-specific targeting. In conclusion, rapid progress in microbubble technology and imaging techniques expands indication for contrast echocardiography and provides powerful tools for us. This article reviews the recent advances in contrast agents, imaging techniques and the relevant clinical applications.