ASSESSMENT OF MYOCARDIAL NECROSIS IMMEDIATELY AFTER INTRACORONARY THROMBOLYSIS BY INTRACORONARY INJECTION OF TECHNETIUM-99M PYROPHOSPHATE

To assess myocardial necrosis immediately after intracoronary thrombolysis, 201Tl and 99mTc pyrophosphate (99mTc PYP) were injected simultaneously into the coronary artery in 25 patients with acute transmural myocardial infarction. In 17 of the 25 patients, the occluded coronary artery was reopened. Minutes after the intracoronary injection of 99mTc PYP into the reopened coronary artery a localized accumulation was seen within the area of the 201Tl defect in all patients. Control i.v. scintigraphy, which was performed in 8 of these 17 patients 1-6 days later, and in 2 patients 18 and 42 days after infarction, revealed a 99mTc PYP spot similar to that of the acute intracoronary 99mTc PYP scintigram in all 10 patients. In the 8 of the 25 patients, in whom intracoronary thrombolysis failed, no localized 99mTc PYP accumulation was seen after injection into the infarct vessel. In 5 of these patients, a control i.v. scintigram, performed 1-8 days later, resulted in a 99mTc PYP spot in the area of the 201Tl defect. In the presence of therapeutic or spontaneous reperfusion 99mTc PYP scintigraphy may provide a useful method of assessing myocardial necrosis during the early stage of an acute myocardial infarction.