Intracoronary Myocardial Scintigraphy During Intracoronary Thrombolysis

Thirty-one patients with acute myocardial infarction underwent intracoronary thrombolysis. Intracoronary thallium scintigrams were obtained before and after thrombolysis. In 16 of the 31 patients intracoronary technetium pyrophosphate scintigraphy was performed simultaneously after thrombolysis. The scintigraphic results were compared with changes in regional ejection fraction in the area of infarction. Two patients initially had a normal left ventricular cineangiogram with no significant ventricular thallium defect before thrombolysis. In 8 patients regional ejection fraction normalised, and all showed substantial new thallium uptake after thrombolysis. In 5 patients regional ejection fraction improved; 3 of these had new thallium uptake with a large residual defect after thrombolysis. Nine patients had no significant change in regional ejection fraction despite thrombolysis, and the initial thallium defect remained unchanged in 7. Four patients had a technetium pyrophosphate accumulation in the area of new thallium uptake. In these 4 patients regional wall motion did not change to the extent expected from the thallium scintigram. In 18 patients with a complete occlusion of the right coronary artery who underwent intracoronary thrombolysis, we performed intracoronary myocardial thallium scintigraphy. Fifteen of the 18 patients had a right ventricular thallium defect, and 17 of the 18 patients had a left ventricular thallium defect before thrombolysis. All 15 patients with a right ventricular thallium defect initially but only 10 of the 17 patients with a left ventricular thallium defect intially showed new thallium uptake after thrombolysis. It is concluded that combined intracoronary thallium-technetium pyrophosphate scintigraphy is helpful in predicting myocardial salvage and areas of irreversible damage immediately after intracoronary thrombolysis. Moreover, intracoronary thallium scintigraphy seems to be a reliable method for studying the incidence of right ventricular involvement in patients with inferior myocardial infarction and the effect of intracoronary thrombolysis on the right ventricular myocardium