A new model for coronary thrombosis in the pig: preliminary results with thrombolysis.

A new model for the electrical induction of coronary thrombosis in the pig is described. In 35 out of 47 experiments (74%) a 100% occluding thrombus developed. In 16 experiments (34%), at least one episode of coronary spasm occurred at the site of electrical stimulation. Flow in the region of the left ventricle supplied by the thrombosed coronary artery decreased from 1.04 +/- 0.21 to 0.09 +/- 0.04 ml/min/g tissue (mean +/- SD). Histological examination showed that the lesion caused by the electrical current occurred through the arterial wall and was quite discrete, measuring a few millimetres in length. Scanning and transmission electron microscopy revealed that the occlusions were caused by typical platelet thrombi. Lysis of the thrombi by the intracoronary administration of porcine plasmin was successful in 15 out of 19 animals (79%). Preliminary results show that thrombolysis after 40 min occlusion restores flow to nearly base-line values, but does not improve regional function in the first 3 h.