[Residual coronary artery stenosis: its shapes immediately after thrombolysis and subsequent time courses]

Changes in shape and the time course of residual coronary artery stenoses following thrombolysis were studied in 36 patients with acute myocardial infarction. The following results were obtained: 1. Residual stenoses after thrombolysis were categorized morphologically in three groups; long segment type (group L, eight patients), segmental type (group S, 18 patients) and filling defect type (group FD, 10 patients). 2. Residual stenoses in group L did not change either as to morphology or severity one month later. Group S did not show morphological change, but 11 of the 18 patients showed slight regression of residual stenoses. In group FD, filling defect images on repeated angiography resolved in all cases within one month. However, characteristic irregularity at the infarct-related coronary arteries were often observed at the same time. 3. Twelve of the 36 patients underwent angiography during three consecutive days to study sequential changes in residual stenoses. Intracoronary thrombi were resolved before the second day, which was compatible with a plasminogen-plasmin system change. 4. Severe coronary artery atherosclerosis may be an important factor in the pathogenesis in group L, while thrombus formation based on ulcerative lesions without significant stenoses may be an important factor in group FD. 5. Mechanical revascularization for the groups L and S patients, and an additional thrombolytic agent for the group FD patients are recommended as further therapy after thrombolysis.