Failure of fluosol DA to enhance the ultrasonic image of infarcted myocardium

The perfluorocarbon Fluosol DA has been reported to increase the subjective echogenicity of infarcted myocardium. To investigate this phenomenon, two-dimensional echocardiograms were recorded in 20 closed-chest dogs before and 24,48,72, and 96 h following permanent coronary artery occlusion. Low-dose Fluosol, 10 ml/kg (LDF) (four dogs), high-dose Fluosol, 25 ml/kg (HDF) (eight dogs), or lactated Ringers 25 ml/kg (LR) (eight dogs) was administered 48 h after occlusion. Left ventricular sections corresponding to the short-axis echocardiographic examination plane were stained with nitroblue tetrazolium 48 h after Fluosol administration. Short-axis echocardiographic studies were evaluated by two blinded observers who found no consistent increase in the echogenicity of the infarcted area in any group. Videodensitometry of the infarcted area, normalized to the average value of two remote areas, confirmed mean post-Fluosol increases of 66% in LR dogs, 65% in LDF dogs, and 107% in HDF animals (p less than 0.001 for all dogs; all intergroup comparisons NS). The increase in videodensity observed in all groups may have occurred as a consequence of volume administration, although changes in infarct intensity occurring over time cannot be excluded.