HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Glover, D. K. Articles by Beller, G. A. Search for Related Content PubMed PubMed Citation Articles by Glover, D. K. Articles by Beller, G. A.

^99mTc-Tetrofosmin Assessment of Myocardial Perfusion and Viability in Canine Models of Coronary Occlusion and Reperfusion

Experimental Cardiology Laboratory, Cardiovascular Division, Department of Medicine, University of Virginia Health Sciences Center, Charlottesville, Virginia

Correspondence: For correspondence or reprints contact: David K. Glover, MD, University of Virginia, Experimental Cardiology Laboratory, Cardiology Division, Box 500 Medical Center, Charlottesville, VA 22908.

ABSTRACT

The goal of this study was to determine whether ^99mTc-tetrofosmin can assess regional flow heterogeneity when injected during sustained coronary artery occlusion and to estimate the degree of myocardial salvage and viability during coronary reperfusion. Methods: In protocol 1, ^99mTc-tetrofosmin, ²⁰¹Tl and microspheres were injected during total left anterior descending (LAD) coronary artery occlusion in five anesthetized open-chested dogs. Protocol 2 dogs underwent LAD occlusion for either 60 min (n = 7) or 180 min (n = 6) followed by 105 min of reperfusion. ^99mTc-tetrofosmin (10 mCi), ²⁰¹Tl (1 mCi) and microspheres were injected 90 min after reflow. In both protocols, myocardial ^99mTc-tetrofosmin and ²⁰¹Tl activities were quantified from regions of interest on ex vivo images and by in vitro well counting. Results: In protocol 1, there was a linear relationship between ²⁰¹Tl (r = 0.96) and ^99mTc-tetrofosmin (r = 0.92) activities and microsphere flow during the occlusion. In protocol 2, the LAD/left circumflex (LCx) defect count ratios for ^99mTc-tetrofosmin and ²⁰¹Tl from images of myocardial slices were comparable in dogs undergoing either 1 or 3 h of LAD occlusion and 105 min of reperfusion. Similarly, the LAD/LCx in vitro count ratios were comparable between ²⁰¹Tl and ^99mTc-tetrofosmin in 1 and 3 h occluded dogs, and significantly lower than the reperfusion flow when these tracers were injected. Uptake of both tracers was depressed to a greater extent in areas of severe ischemic damage. Conclusion: These data suggest that administration of ^99mTc-tetrofosmin during coronary occlusion accurately delineates the flow heterogeneity. When given after reperfusion, ^99mTc-tetrofosmin uptake was significantly reduced in reperfused, infarcted areas and was reflective of viability and the degree of myocardial salvage in addition to reperfusion flow. These experimental studies validate the clinical use of ^99mTc-tetrofosmin for assessing persistent coronary artery occlusion, and infarct size and myocardial viability after reperfusion.

Key Words: ²⁰¹Tl • ^99mTc-tetrofosmin • radionuclide imaging • myocardial infarction

This article has been cited by other articles:

				W. M. Schaefer, B. Nowak, H.-J. Kaiser, K.-C. Koch, S. Block, J. vom Dahl, and U. Buell Comparison of Microsphere-Equivalent Blood Flow (15O-Water PET) and Relative Perfusion (99mTc-Tetrofosmin SPECT) in Myocardium Showing Metabolism-Perfusion Mismatch J. Nucl. Med., January 1, 2003; 44(1): 33 - 39. [Abstract] [Full Text] [PDF]

				A. Keck, K. Hertting, Y. Schwartz, R. Kitzing, M. Weber, B. Leisner, C. Franke, E. Bahlmann, C. Schneider, T. Twisselmann, et al. Electromechanical mapping for determination of myocardial contractility and viability: A comparison with echocardiography, myocardial single-photon emission computed tomography, and positron emission tomography J. Am. Coll. Cardiol., September 18, 2002; 40(6): 1067 - 1074. [Abstract] [Full Text] [PDF]

				G. Vanzetto, D. K. Glover, M. Ruiz, D. A. Calnon, R. Pasqualini, D. D. Watson, and G. A. Beller 99mTc-N-NOET Myocardial Uptake Reflects Myocardial Blood Flow and Not Viability in Dogs With Reperfused Acute Myocardial Infarction Circulation, May 23, 2000; 101(20): 2424 - 2430. [Abstract] [Full Text] [PDF]