To determine whether contrast medium in the left ventricle improves endocardial border delineation, enabling better assessment of left ventricular (LV) wall motion, a 5% solution of sonicated albumin microspheres was administered in 30 adult patients who exhibited endocardial border drop-out of 20% or more on routine echocardiography. The investigator and two blinded reviewers evaluated efficacy using an opacification grading system of 0 to 3+, with 0 indicating no contrast effect and 3+ indicating full opacification of the left ventricle. A score of 2+ or greater indicated effective opacification. Border delineation improvement was defined as a change from grade A (not well delineated) to grade B, C, or D (well delineated) of at least 1 of 6 LV wall segments. All patients received an initial injection of 0.08 cc/kg. If this volume produced LV opacification of at least 2+, the patient received two additional injections of 0.14 cc/kg and 0.08 cc/kg, each given 5 minutes apart. Otherwise, the patient received a final injection of 0.22 cc/kg. In all cases, the patient's arm was raised after injection to enhance venous passage. The total number of patients exhibiting 2+ or greater opacification was 29 (97%) when graded by the investigator and 27 (90%) when graded by the blinded observers. The investigator noted improved border delineation in 90% of patients, and the blinded observers noted improvement in 97% (excluding 1 patient who would have received a higher dose of contrast agents if scored by a blinded observer). Investigator confidence in assessing LV wall motion improved in 24 (80%) of the 30 studies.(ABSTRACT TRUNCATED AT 250 WORDS)