Myocardial uptake of 99mTc-tetrofosmin, sestamibi, and 201Tl in a model of acute coronary reperfusion
Department of Nuclear Medicine
Animals; Coronary Circulation; Coronary Disease; Hemodynamics; Male; *Myocardial Reperfusion; Myocardium; Nitroblue Tetrazolium; Organophosphorus Compounds; Organotechnetium Compounds; Rats; Rats, Sprague-Dawley; Staining and Labeling; Technetium Tc 99m Sestamibi; Thallium; Thallium Radioisotopes
Cardiology | Circulatory and Respiratory Physiology
BACKGROUND: To investigate whether tetrofosmin uptake is affected by myocardial viability as has been noted for 201Tl and sestamibi, we analyzed the initial and delayed distribution patterns of tetrofosmin in a rat coronary artery occlusion-reperfusion model. METHODS AND RESULTS: Animals were intubated and ventilated, and their arterial pressures were monitored. A left thoracotomy was performed. After 1-hour occlusion and 1-hour reperfusion of a major branch of the circumflex artery, 201Tl and either tetrofosmin or sestamibi were injected intravenously. Radiolabeled microspheres were used to document the area at risk and reperfusion. Five minutes or 1 hour after administration of the diffusible tracers, the animals were killed. Tracer distribution was determined by use of segmental tissue analysis, and tissue viability was determined by use of histochemical staining. Both the initial and delayed retention of tetrofosmin were sensitive to myocardial viability, as shown by significantly lower uptake (30 +/- 14%) and retention (24 +/- 12%) of tetrofosmin in the nonviable segments compared with the viable segments. In addition, the initial myocardial distribution of tetrofosmin was similar to that noted for 201Tl, but after 1 hour of tracer circulation, the tetrofosmin tissue distribution appeared unchanged compared with the initial regional blood flow distribution. This is in direct contrast to our present observations of significant 201Tl redistribution and some changes in sestamibi distribution as well. CONCLUSIONS: The clinical implication of these observations suggests that initial and delayed imaging after tetrofosmin administration would reflect both the initial regional blood flow pattern and myocardial viability.
Circulation. 1996 Nov 15;94(10):2605-13.
Takahashi, Norio; Reinhardt, Christopher P.; Marcel, Robin; and Leppo, Jeffrey A., "Myocardial uptake of 99mTc-tetrofosmin, sestamibi, and 201Tl in a model of acute coronary reperfusion" (1996). Open Access Articles. 457.