Myocardial thallium-201 kinetics and regional flow alterations with 3 hours of coronary occlusion and either rapid reperfusion through a totally patent vessel or slow reperfusion through a critical stenosis

• Published in: Journal of the American College of Cardiology 1987-01, Vol.9 (1), p.109-118
• Main Authors: Granato, Jerome E., Watson, Denny D., Flanagan, Terry L., Beller, George A.
• Format: Article
• Language: English
• Subjects: Animals; Arterial Occlusive Diseases - diagnostic imaging; Arterial Occlusive Diseases - therapy; Biological and medical sciences; Cardiology. Vascular system; Coronary Circulation; Coronary Disease - diagnostic imaging; Coronary Disease - therapy; Coronary heart disease; Dogs; Heart; Heart - diagnostic imaging; Kinetics; Medical sciences; Radioisotopes; Radionuclide Imaging; Thallium; Time Factors; Vascular Patency
• ISSN: 0735-1097; 1558-3597
• DOI: 10.1016/S0735-1097(87)80089-X

Myocardial thallium-201 kinetics and regional blood flow alterations were examined in a canine model using 3 hours of coronary occlusion and different methods of reperfusion. Group I comprised 10 dogs undergoing a 3 hour left anterior descending artery occlusion and no reperfusion. Group II comprised seven dogs undergoing 3 hours of left anterior descending artery occlusion and rapid reperfusion through a totally patent vessel. Group III comprised 10 dogs undergoing 3 hours of left anterior descending artery occlusion and slow reperfusion through a residual stenosis. All dogs received 1.5 mCi of thallium-201 after 40 minutes of coronary occlusion. During occlusion and 2 hours of reperfusion, serial hemodynamic, blood flow and myocardial thallium-201 activity measurements were made. The relative thallium-201 gradient (normal zone minus ischemic zone activity when initial normal activity is expressed as 100%) during left anterior descending coronary occlusion was similar in all groups. Group I, 87 ± 3%; Group II, 78 ± 6%; Group III, 83 ± 6% (p = NS). After 2 hours of either method of reperfusion, the final relative gradient had decreased to a similar level (Group II, 51 ± 9%; Group III, 42 ± 6%). These values were not significantly different from the final relative thallium-201 gradient seen in dogs undergoing a sustained 3 hour occlusion (Group I, 55 ± 5%). After 2 hours of reperfusion, both methods of reflow were associated with similar degrees of “no reflow.” Transmural flows in the central ischemic zone were 89 ± 10% of normal in Group II and 71 ± 6% of normal in Group III after reperfusion, with both flows substantially higher than the relative thallium-201 activities in these dogs. Infarct size (percent of left ventricle) determined with triphenyltetrazolium chloride was similar in all groups (Group I, 24 ± 4%; Group II, 29 ± 4%; Group III, 25 ± 4%). Thus, in this experimental canine model, 3 hours of coronary occlusion followed by either rapid reperfusion through a totally patent vessel or slow reperfusion through a critical stenosis resulted in little delayed thallium-201 redistribution or myocardial salvage as assessed histologically, despite significant recovery of regional flow.