TEBOROXIME IS A MARKER OF REPERFUSION AFTER MYOCARDIAL-INFARCTION

Background. It has been shown that serial teboroxime imaging can rapid ly assess coronary perfusion in viable myocardial distributions, Howev er, the myocardial uptake of teboroxime after reperfusion of acutely i nfarcted myocardium has not been critically evaluated, The study objec t was to assess whether teboroxime uptake in acutely infarcted myocard ium is linearly related to blood flow, Methods and Results. Seventeen New Zealand rabbits underwent occlusion of the left circumflex coronar y artery for 1 hour, The animals were reperfused for 2 hours and, just before they were killed, teboroxime was injected, The infarct was del ineated by triphenyltetrazolium chloride staining. Normalized blood fl ow and myocardial teboroxime distribution in the infarcted myocardium was determined by gamma well counting, Ex vivo planar images of the le ft ventricle were also acquired, Transmural myocardial infarction was documented in all 17 rabbits, The mean infarct size a one standard dev iation was 25.5% +/- 10.7% (range, 11.9% to 43.3%), There was a direct linear relationship between normalized reperfusion flow and myocardia l teboroxime distribution in the infarct zone (r = 0.91), A direct lin ear relationship between defect size and normalized infarct zone reper fusion was also evident on the ex vivo planar studies (r = 0.70),Concl usion. This study shows that the initial uptake of teboroxime in acute ly infarcted myocardium is linearly related to blood flow, Teboroxime has properties that are well suited for the early evaluation of infarc t zone perfusion.