Experimental myocardial infarct imaging following intravenous administration of iodine-131 labeled antibody (Fab')2 fragments specific for cardiac myosin.

Canine myocardial infarcts resulting from ligation of the left anterior descending coronary artery were localized in vivo by gamma scintigraphy following the intravenous injection of l'I anticardiac myosin antibody (Fab')2. The anteroapical location of the image was confirmed by demonstration of the blood pool with "mTc sulfur colloid, and by subsequent imaging of the excised heart. The scintigram of the excised heart, following prior in vivo injection of "'Ce-microspheres, showed a region of diminished radioactivity near the apex which corresponded precisely to the region of 'lsl antibody (Fab')% uptake. Well defined areas of 'l9I antibody (Fab')2 activity in the region of infarction were consistently imaged at 48 hours in