Relationship between regional myocardial blood flow and thallium-201 distribution in the presence of coronary artery stenosis and dipyridamole-induced vasodilation.

Mays, A E; Cobb, Frederick R.

doi:10.1172/jci111339

Cited by 44 publications

(6 citation statements)

References 33 publications

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“…Another potential clinical use of ATPis in providing coronary vasodilation in thallium scintigraphic study or echocardiographic study (34)(35)(36)(37). The short half-life of ATP compared with that of dipyridamole maylessen the risk of prolonged coronary ischemia due to coronary steal and reduce the time required for redistribution of the isotope.…”

Section: Resultsmentioning

confidence: 99%

Effect of Adenosine Triphosphate on Human Coronary Circulation.

et al. 1998

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Weinvestigated in humansthe effects of adenosine triphosphate (ATP), administered by intracoronary bolus (4-16 (Llg) or intravenous infusion (25-200 Hg/kg/min), on coronary and systemic hemodynamics and electrocardiogram (ECG) variables. All patients had normal epicardial coronary arteries. The maximal coronary blood flow velocity (CBFV)was determined with intracoronary bolus of papaverine. A 12 |ig bolus of ATP (n=12) caused maximal coronary hyperemia similar to that caused by papaverine. Intracoronary boluses caused a small brief decrease in arterial pressure but no significant changes in HRor ECGvariables. Intravenous infusion ofATP at 150 |Llg/kg/min (n=15) caused a decrease in the coronary resistance index similar to that caused by papaverine, but the rate of increase in CBFVby ATPwas smaller than that caused by papaverine. No patients had a significant change in ECGvariables, but some patients (40 %) had a serious decrease in arterial pressure. These studies suggest that maximalcoronary vasodilation can be achieved safely with intracoronary ATPadministration and that intravenous infusions at 150 |0g/kg/min cause near-maximal coronary hyperemia in most patients. (Internal Medicine 37: 818-825, 1998)

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Section: Resultsmentioning

confidence: 99%

Effect of Adenosine Triphosphate on Human Coronary Circulation.

et al. 1998

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“…Although the immediate distribution of thallium in acutely ischemic myocardium is proportional to the reduction in flow (17,20), there is a well-described redistribution of thallium over time with differential washout in normal compared with ischemic myocardium (9,20,22). A greater washout rate in normal myocardium results in a progressive reduction in the relative difference in thallium deposition in normal and ischemic myocardium (9,20,22).…”

Section: Discussionmentioning

confidence: 99%

Comparison of thallium deposition with segmental perfusion in pigs with chronic hibernating myocardium

Baldwa

Rana²,

Canty³

et al. 2008

American Journal of Physiology-Heart and Circulatory Physiology

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Baldwa S, Rana M, Canty JM, Fallavollita JA. Comparison of thallium deposition with segmental perfusion in pigs with chronic hibernating myocardium. Am J Physiol Heart Circ Physiol 295: H2522-H2529, 2008. doi:10.1152/ajpheart.00761.2008.-Viable, chronically dysfunctional myocardium with reduced resting flow (or hibernating myocardium) is an important prognostic factor in ischemic heart disease. Although thallium-201 imaging is frequently used to assess myocardial viability in patients with ischemic cardiomyopathy, there are limited data regarding its deposition in hibernating myocardium, and this data suggest that thallium retention may be supernormal compared with control myocardium. Accordingly, pigs (n ϭ 7) were chronically instrumented with a 1.5 mm Delrin stenosis on the proximal left anterior descending coronary artery (LAD) to produce hibernating myocardium. Four months later, severe anteroapical hypokinesis was documented with contrast ventriculography (wall motion score, 0.7 Ϯ 0.8; normal ϭ 3), and microsphere measurements confirmed reduced resting flow (LAD subendocardium, 0.78 Ϯ 0.34 vs. 0.96 Ϯ 0.24 ml⅐min Ϫ1 ⅐g Ϫ1 in remote; P Ͻ 0.001). Absolute deposition of thallium-201 and insulin-stimulated [18 F]-2 fluoro-2-deoxyglucose (FDG) were assessed over 1 h and compared with resting flow (n ϭ 704 samples). Thallium-201 deposition was only weakly correlated with perfusion (r 2 ϭ 0.20; P Ͻ 0.001) and was more homogeneously distributed (relative dispersion, 0.12 Ϯ 0.03 vs. 0.29 Ϯ 0.10 for microsphere flow; P Ͻ 0.01). Thus after 1 h relative thallium-201 (subendocardium LAD/remote, 0.96 Ϯ 0.16) overestimated relative perfusion (0.78 Ϯ 0.32; P Ͻ 0.0001) and underestimated the relative reduction in flow. Viability was confirmed by both histology and preserved FDG uptake. We conclude that under resting conditions, thallium-201 redistribution in hibernating myocardium is nearly complete within 1 h, with similar deposition to remote myocardium despite regional differences in flow. These data suggest that in this time frame thallium-201 deposition may not discriminate hibernating myocardium from dysfunction myocardium with normal resting flow. Since hibernating myocardium has been associated with a worse prognosis, this limitation could have significant clinical implications.

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“…The protocol is shown schematically in figure lb and is modeled according to Mays and Cobb [10]. Dogs were prepared surgically as described above.…”

Section: Experimental Protocolmentioning

confidence: 99%

Detection Sensitivity of Coronary Artery Stenosis by <sup>99m</sup>Tc-Sestamibi and <sup>201</sup>T1 in Canine Models of Partial and Subcritical Stenosis

Mousa¹,

Cooney²

1991

Cardiology

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This study was designed to assess the sensitivity of the monocationic ^99mTc-hexakis-2-methoxy, 2-methylpropylisonitrile (^99mTc-sestamibi) as compared to ²⁰¹T1 in the detection of regional myocardial blood flow deficits in dogs with different degrees of stenosis with or without dipyridamole. Regional myocardial distribution of ^99mTc-sestamibi and ²⁰¹T1 was determined in mongrel dogs under different levels of left arterial descending coronary artery (LAD) stenosis (30–45, 60–70 and 100% flow reduction) as monitored with electromagnetic flow probes and radiolabeled microspheres. Both ^99mTc-sestamibi and ²⁰¹T1 distribute in direct proportion to blood flow at all levels of stenosis (r² = 0.90–0.99). Quantitatively, both tracers underestimate the resting flow stenosis. The regional myocardial distribution for both ^99mTc and ^20lTl was also determined in subcritically stenosed mongrel dogs. This was produced by placing a balloon cuff around the LAD, infusing dipyridamole to peak hyperemic flow and immediately stenosing the LAD to basal flow. Stenosed to normal zone flow ratios were 0.68 ± 0.01 compared to ^99mTc and ²⁰¹T1 ratios of 0.73 ± 0.04 and 0.80 ± 0.05, respectively. These data suggest that ^99mTc is at least as sensitive as ²⁰¹T1 in the detection of different degrees of critical and subcritical coronary artery stenosis.

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Relationship between regional myocardial blood flow and thallium-201 distribution in the presence of coronary artery stenosis and dipyridamole-induced vasodilation.

Cited by 44 publications

References 33 publications

Effect of Adenosine Triphosphate on Human Coronary Circulation.

Effect of Adenosine Triphosphate on Human Coronary Circulation.

Comparison of thallium deposition with segmental perfusion in pigs with chronic hibernating myocardium

Detection Sensitivity of Coronary Artery Stenosis by <sup>99m</sup>Tc-Sestamibi and <sup>201</sup>T1 in Canine Models of Partial and Subcritical Stenosis

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