Effect of ischemia and postischemic dysfunction on myocardial uptake of technetium-99m-labeled methoxyisobutyl isonitrile and thallium-201

Journal Article · Thu Nov 30 23:00:00 EST 1989 · Journal of the American College of Cardiology; (USA)

DOI:https://doi.org/10.1016/0735-1097(89)90034-X· OSTI ID:5083752

Sinusas, A J; Watson, D D; Cannon, Jr, J M; Beller, G A ^[1]

---

1. Univ. of Virginia Health Sciences Center, Charlottesville (USA)

The myocardial uptake of a new technetium-99m-labeled myocardial perfusion agent, methoxyisobutyl isonitrile (Tc-99m MIBI), and thallium-201 was correlated with microsphere flow in an open chest canine model of low coronary flow and postischemic dysfunction. Eighteen dogs were given an injection of thallium-201 (0.5 mCi) and Tc-99m MIBI (5 mCi) either after 40 min of partial left anterior descending artery occlusion (Group I, 10 dogs) or during reperfusion after 15 min of left anterior descending artery occlusion (Group II, 8 dogs). Regional dysfunction was documented during injection in both groups by quantitative two-dimensional echocardiography. Regional blood flow was assessed by radiolabeled microspheres. The heart was excised 15 min after radionuclide injection and the left ventricle divided into 96 segments for gamma well counting. Among Group I dogs, central ischemic thallium-201 and Tc-99m MIBI activity (expressed as a percent of the activity in the corresponding nonischemic zone) was comparable, respectively, for endocardial (54 +/- 17% and 52 +/- 17%), mid-wall (71 +/- 20% and 69 +/- 17%) and epicardial (89 +/- 13% and 94 +/- 9%) segments and increased proportionally with flow. There was a good linear correlation among these endocardial segments between flow and both thallium-201 (r = 0.78) and Tc-99m MIBI (r = 0.85) activity. Among Group II dogs, central ischemic endocardial flow (59 +/- 14%) was comparable to thallium-201 (70 +/- 18%) and Tc-99m MIBI (74 +/- 12%) activity. Similarly, relative endocardial flow in the intermediate ischemic region (71 +/- 11%) was comparable to thallium-201 (77 +/- 11%) and Tc-99m MIBI (81 +/- 10%) activity. Thus, myocardial uptake of Tc-99m MIBI and thallium-201 is comparable under conditions of low coronary flow and postischemic dysfunction and closely parallels flow alterations.

• OSTI ID: 5083752
• Journal Information: Journal of the American College of Cardiology; (USA), Journal Name: Journal of the American College of Cardiology; (USA) Vol. 14:7; ISSN 0735-1097; ISSN JACCD
• Country of Publication: United States
• Language: English

Related Subjects

550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BLOOD FLOW
BLOOD PRESSURE
BODY
CARDIOVASCULAR DISEASES
CARDIOVASCULAR SYSTEM
DAYS LIVING RADIOISOTOPES
DIAGNOSIS
DISEASES
DOGS
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
HEART
HEAVY NUCLEI
HOURS LIVING RADIOISOTOPES
INTERMEDIATE MASS NUCLEI
ISOMERIC NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LABELLED COMPOUNDS
MAMMALS
MICROSPHERES
NITRILES
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
RADIOISOTOPES
RADIOPHARMACEUTICALS
SECONDS LIVING RADIOISOTOPES
TECHNETIUM 99
TECHNETIUM ISOTOPES
THALLIUM 201
THALLIUM ISOTOPES
ULTRASONOGRAPHY
UPTAKE
VERTEBRATES
YEARS LIVING RADIOISOTOPES