REGIONAL DISTRIBUTION OF I-123 (ORTHO-IODOPHENYL)-PENTADECANOIC ACID AND TC-99(M)-MIBI IN RELATION TO WALL MOTION AFTER THROMBOLYSIS FOR ACUTE MYOCARDIAL-INFARCTION

To characterize the myocardium after thrombolytic therapy for infarcti on single photon emission computed tomographic (SPECT) studies with I- 123-(ortho-iodophenyl)-pentadecanoic acid (oPPA) and Tc-99m-methoxyiso butyl isonitrile (MIBI) were obtained at rest in nine patients within a fortnight after the acute event. A decreased oPPA activity compared to MIBI was observed in 15/45 segments (7/9 patients). The segments wi th discordant oPPA/MIBI activities showed less severe wall motion abno rmalities than the segments with concordant decreased oPPA and MIBI ac tivities (P=0.004). A significant association was found between discor dant oPPA/MIBI activities and the early evolution of wall motion follo wing thrombolysis: discordant oPPA/MIBI activities were present in nin e of the 11 segments (82%) with improved wall motion, while the wall m otion of the seven segments with similar decreased oPPA and MIBI activ ities was unchanged or had deteriorated (P=0.018). It is concluded tha t metabolic abnormalities often persist longer than perfusion and wall motion abnormalities soon after thrombolysis, and that I-123-oPPA in combination with Tc-99m-MIBI is useful to demonstrate myocardial areas which have been salvaged by thrombolysis.