[Long-term follow-up of thallium-201 myocardial scintigraphy in acute myocardial infarction--clinical significance of reverse redistribution during acute period].

: To clarify the viability of myocardium in acute myocardial infarction, we examined 18 patients scintigraphically. They underwent rest or stress imaging and delayed imaging of thallium-201 during acute, convalescent and chronic periods. During acute period, a scintigraphic finding of the delayed filling in was observed in 9 cases (50%; Redistribution group). Worsening of the delayed image was observed in 6 cases (33%; Reverse redistribution group). No scintigraphic change of the perfusion defect was observed in 3 cases (17%; No change group). In reverse redistribution group, a remarkable improvement of the delayed image was observed through acute, convalescent and chronic periods. In redistribution group and no change group, no significant improvement was observed. We conclude that the myocardium of the reverse redistribution region during acute period may be viable. In the reverse redistribution region, recanalization of the coronary artery possibly protects myocardial damage from necrosis.