Myocardial uptake of Tc-99m-N-NOET and (TI)-T-201 during dobutamine infusion - Comparison with adenosine stress

Article

关键词: TC-99M SESTAMIBI UPTAKE;    BLOOD-FLOW;    CORONARY STENOSIS;    TL-201;    NOET;    REDISTRIBUTION;    MITOCHONDRIAL;    TOMOGRAPHY;    RETENTION;    EXERCISE;   

DOI  :  10.1161/01.CIR.100.15.1653

来源: SCIE

【 摘 要 】

Background-The myocardial uptake of Tc-99m-sestamibi is attenuated by dobutamine stress, resulting in underestimation of ischemia. N-Ethyl-N-ethoxy-dithiocarbamato-N-Tc-99m (Tc-99m-N-NOET) is a new Tc-99m-labeled perfusion agent that is highly extracted by the myocardium by a mechanism different from that defined for Tc-99m-sestamibi. We therefore hypothesized that Tc-99m-N-NOET uptake would not be attenuated by dobutamine and that Tc-99m-N-NOET uptake would be comparable to Tl-201 uptake during dobutamine stress. Methods and Results-In 28 open-chest dogs, after placement of a stenosis in the left anterior descending coronary artery that reduced flow reserve by >50%, adenosine (300 mu g . kg(-1) . min(-1); n = 15) or dobutamine (2.5 to 30 mu g . kg(-1) . min(-1); n = 13) was infused. During adenosine stress, the stenotic-to-normal activity ratio for Tc-99m-N-NOET was 0.55+/-0.05. The stenotic-to-normal flow ratio was 0.33+/-0.04 at the time of Tc-99m-N-NOET injection. During dobutamine stress, the stenotic-to-normal Tc-99m-N-NOET activity ratio was 0.63+/-0.04, comparable to the Tl-201 activity ratio of 0.59+/-0.04. The stenotic-to-normal flow ratio was 0.47+/-0.04 at the time of Tc-99m-N-NOET and Tl-201 injection. The relationship between Tc-99m-N-NOET uptake and blood flow was comparable for adenosine and dobutamine stress, with no evidence of attenuation of Tc-99m-N-NOET extraction by dobutamine. Conclusions-in the presence of coronary stenoses that reduced regional flow reserve, the myocardial uptake of Tc-99m-N-NOET and Tl-201 are closely proportional to blood flow during both adenosine and dobutamine stress, suggesting that the adverse effect of dobutamine on Tc-99m-sestamibi uptake is a tracer-specific phenomenon rather than a generalized effect. The clinical implication of this finding is that Tc-99m-N-NOET might be preferable to Tc-99m-sestamibi when used with dobutamine stress for detection of coronary stenoses.

【 授权许可】

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