Assessment of myocardial perfusion with contrast two-dimensional echocardiography.

Myocardial contrast echocardiography (MCE) is a new technique capable of assessing regional myocardial perfusion in vivo in real time. At present, this technique involves the intraaortic or intracoronary injection of microbubbles of air. As these microbubbles traverse the myocardium, they produce opacification of the myocardium in concomitantly performed echocardiographic images. In animal models, MCE has been demonstrated to assess accurately the in vivo risk area (region of the myocardium at risk for necrosis after acute coronary occlusion). It has also been shown to provide quantitative information on regional myocardial blood flow (both antegrade and collateral). This technique has been demonstrated to be safe in humans. In clinical studies it has been shown to be a useful adjunct to cardiac catheterization, particularly in the assessment of coronary blood flow reserve and collateral blood flow. MCE is also used in the operating room to assess regional myocardial perfusion before and after bypass graft operations. The microbubbles used for MCE were shown to opacify the left ventricular cavity after their injection into a peripheral vein. If myocardial opacification after venous injection can be achieved, MCE will have the potential for the simultaneous noninvasive in vivo assessment of regional myocardial perfusion and function in humans.