Systematic analysis of contrast echocardiograms.

Contrast echocardiography was first described in 1968. Since then, many reports have described clinical and experimental uses for the technique. Contrast echocardiography is performed at least occasionally in most echocardiography laboratories, but most physicians use this technique merely to determine the presence of a shunt or, more rarely, for structure identification. Contrast echocardiography can provide much more information. Some different types of information available from contrast echocardiographic records are discussed, including timing of contrast appearance within the cardiac cycle, relative timing of appearance in different cardiac structures, relative intensity of contrast opacification, cyclical changes in contrast opacification, negative contrast effect, slope of contrast trajectories on M-mode contrast echocardiography, and clearance times.