Radioiodine uptake by the infarcted heart

An increased uptake of radioiodine by the infarcted heart has been reported by us previously. Forty-nine patients have now been investigated: twenty-three patients with recent myocardial infarction, twenty-one control patients and five patients in whom exact diagnostic classification as to the presence or absence of infarction was impossible. In all patients with infarction, an increased radioiodine uptake over the area of the heart in comparison with the corresponding area on the right side of the chest could be observed. The increased left-to-right ratio appeared after twenty-four to forty-eight hours and was also noticeable at least on the sixth, the seventh or the eighth day after iodine administration. The 100 μc. dose of I 131 seems to be a suitable one with the instruments employed. The phenomenon of increased radioiodine uptake by the infarcted heart, although its nature is still poorly understood, appears to have some clinical diagnostic value.