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 infarction single photon emission computed tomographic (SPECT) studies with I-123-(ortho-iodophenyl)-pentadecanoic acid (oPPA) and Tc-99m-methoxyisobutyl 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 with discordant oPPA/MIBI activities showed less severe wall motion abnormalities than the segments with concordant decreased oPPA and MIBI activities (P=0.004). A significant association was found between discordant oPPA/MIBI activities and the early evolution of wall motion following thrombolysis: discordant oPPA/MIBI activities were present in nine of the 11 segments (82%) with improved wall motion, while the wall motion of the seven segments with similar decreased oPPA and MIBI activities was unchanged or had deteriorated (P=0.018). It is concluded that 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.