Harmonic Power Doppler Contrast Echocardiography: Preliminary Experimental Results.

This preliminary experimental study demonstrates the potential usefulness of harmonic power Doppler imaging in producing left ventricular myocardial opacification and demonstrating intramyocardial coronary vessels during contrast echocardiography using Levovist, a saccharide-based contrast agent. The contrast effect was most dramatic when a vasodilator such as dipyridamole or nitroglycerin was used in conjunction with contrast injections of Levovist. No significant myocardial opacification was noted with B-mode harmonic imaging alone.

Color Doppler Visualization of Intramyocardial Coronary Arteries Using a New Echo System: Effect of Contrast Enhancement and Vasodilation.

Utilizing a new echocardiographic system, intramyocardial coronary arteries could be demonstrated by color Doppler in a small number of open chest animals. Both intravenous and intracoronary injections of a contrast agent (Levovist) resulted in significant enhancement of color flow signals with an increase in the length, width, and the number of these vessels. Similar results were obtained with intravenous infusion and direct intracoronary injections of a vasodilator (adenosine).