[Detection of viable myocardium by means of stress test with thallium 201: usefulness of delayed imaging].

Delayed imaging may help detect viable myocardium after stress Thallium scintigraphy. In 22 patients who had sustained myocardial infarction we performed a stress Thallium test followed by imaging after 24 hr. Delayed reperfusion was observed in 57% of segments showing no reperfusion at 4 hr, which is similar to findings reported in the literature. We proposed that delayed imaging should be performed in all patients showing perfusion defects at 4 hr. Even though a better image may be obtained using reinjection of Thallium, delayed imaging may be the technique of choice to reduce the cost of the test.