[Myocardial contrast echocardiography using artificial blood (Fluosol-DA): a comparison with left ventricular wall...

In the present study, myocardial contrast echocardiographic enhancement was compared with left ventricular wall motion in an experimental ischemic heart according to the degree of narrowing of the coronary artery. Artificial blood (Fluosol-DA) was used as a contrast agent. In eight adult mongrel dogs, ischemic hearts with 0, 50, 70 to 90 and 100% narrowing of the coronary artery were produced by controlling a balloon catheter in a closed-chest system. Fluosol-DA was injected into the left main coronary artery and myocardial contrast echocardiograms were recorded. The short-axis images of the left ventricle were subdivided into octants using a "floating" reference system to analyze wall motion by an image analyzer (Cardias GP2000), and to evaluate density values in the echocardiogram by densitometry (MSR Vx-50). With 0 and 50% narrowing of the coronary artery, the entire circumferential myocardium was filled with marked contrast echoes, and no change was observed in left ventricular wall motion. In 70 to 90% narrowing, the perfusion area of the narrowed coronary artery was filled with mild contrast echoes compared to the other areas showing marked contrast echoes. But no change was observed in left ventricular wall motion. During total occlusion, the perfusion area of the occluded coronary artery was not filled with contrast echoes and a distinct difference was observed between this and the other areas. Marked abnormality of wall motion was also observed. The area with abnormal wall motion tended to be wider than the area of contrast enhancement defect. The ischemic area can therefore be more accurately confirmed by simultaneously observing the changes in contrast echocardiographic enhancement and in wall motion abnormalities.