Determinants of infarct size in patients successfully treated by intracoronary thrombolysis.

In 125 patients successfully treated by intracoronary thrombolysis, data were analyzed to determine the amount of regional wall motion impairment. In 85 patients with complete occlusion of the affected vessel and successful recanalization, ventriculographic study could be performed immediately after recanalization of the vessel and repeated 3 days thereafter. Unexpectedly, no correlation could be seen between the amount of wall motion impairment and the time interval of coronary vessel occlusion. For assessment of other influencing factors two subgroups were analyzed, one with large infarction despite short occlusion time and the other with small infarction despite long occlusion time. The significant differences between these two groups was in regard to the occluded coronary vessels: In the first group, most patients had anterior infarctions caused by left anterior descending (LAD) occlusion, whereas in the second group, there were no LAD occlusions at all. According to the data that we compiled, the location of the occluded coronary vessel was the most important factor in determining infarct size. Taking this into account, recovery of the impaired wall motion up to the third day after infarction was separately analyzed in LAD occlusion or inferior infarction and was found to be more pronounced in the first. Immediate recovery after recanalization however, which could be analyzed in 40 patients who had angiographic studies before recanalization as well as afterwards, was more pronounced in inferior infarction.