New technologies applied to stress echocardiography: myocardial contrast echocardiography.
The development of new echocardiographic contrast agents that can be injected intravenously and can opacify left-sided cardiac chambers has offered a contribution in the field of stress-echocardiography for two main reasons: (1) the improvement of visualization of the endocardial border and thus facilitating recognition of wall motion abnormalities during pharmacological stress or physical exercise; and (2) the obtaining of information on myocardial perfusion during stress examinations. This review will consider: (1) the improvement of diagnostic accuracy during pharmacological stress or physical exercise obtained with the administration of echo-contrast agents; (2) the results of major studies for comparison of the myocardial contrast echocardiography technique versus single-photon emission computed tomography (SPECT) and coronary angiography; (3) the added value for studying perfusion other than wall motion analysis during stress echo; and (4) the advantages and limitations of different stress modalities. New multicenter studies should now definitively clarify the choice of the best contrast agents and create protocols for myocardial contrast echocardiography using different methods of image acquisition in order to unify the diagnostic process before a 'label approved' for perfusion of contrast echocardiographic agents. Finally, caution should be considered when contrast agents are used in the acute phase of myocardial infarction or ischemia.