Comparison of thallium deposition with segmental perfusion in pigs with chronic hibernating myocardium.
Comparison of thallium deposition with segmental perfusion in pigs with chronic hibernating myocardium.
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猪慢性冬眠心肌铊沉积与分段灌注的比较。
DOI：
10.1152/ajpheart.00761.2008
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
Fallavollita,JamesA
中科院分区：
文献类型：
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作者：
Baldwa,Sunil;Rana,Muzamil;CantyJr,JohnM;Fallavollita,JamesA
存活的、慢性功能障碍的心肌伴静息血流减少（或冬眠心肌）是缺血性心脏病的一个重要预后因素。虽然铊-201显像常用于评估缺血性心肌病患者的心肌活力，但关于其在冬眠心肌中沉积的数据有限，这些数据表明，与对照心肌相比，铊的潴留可能是超常的。因此，猪（n= 7）在冠状动脉左前降支（LAD）近端长期植入1.5 mm Delrin狭窄，以产生冬眠心肌。4个月后，造影剂心室造影记录到严重的前心尖运动功能减退（室壁运动评分，0.7 ± 0.8;正常= 3），微球测量证实静息血流减少（LAD内膜下，0.78 ± 0.34 vs.远端0.96 ± 0.24 ml·min-1·g-1;P< 0.001）。在1小时内评估铊-201和胰岛素刺激的[18 F]-2-氟-2-脱氧葡萄糖（FDG）的绝对沉积，并与静息血流（n= 704个样本）进行比较。铊-201沉积与灌注仅弱相关（r2= 0.20;P< 0.001），并且分布更均匀（相对分散度，0.12 ± 0.03对微球流量的0.29 ± 0.10;P< 0.01）。因此，1小时后，相对铊-201（LAD/远端，0.96 ± 0.16）高估了相对灌注（0.78 ± 0.32;P< 0.0001），低估了相对血流减少。通过组织学和保存的FDG摄取证实了活力。我们的结论是，在静息条件下，铊-201在冬眠心肌的再分布是在1小时内几乎完成，与远程心肌的沉积，尽管区域流量的差异。这些数据表明，在这个时间范围内，铊-201沉积可能无法区分冬眠心肌与正常静息血流的功能障碍心肌。由于冬眠心肌与更差的预后有关，这种局限性可能具有重要的临床意义。
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= 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 ± 0.8; normal = 3), and microsphere measurements confirmed reduced resting flow (LAD subendocardium, 0.78 ± 0.34 vs. 0.96 ± 0.24 ml·min−1·g−1in remote;P< 0.001). Absolute deposition of thallium-201 and insulin-stimulated [18F]-2 fluoro-2-deoxyglucose (FDG) were assessed over 1 h and compared with resting flow (n= 704 samples). Thallium-201 deposition was only weakly correlated with perfusion (r2= 0.20;P< 0.001) and was more homogeneously distributed (relative dispersion, 0.12 ± 0.03 vs. 0.29 ± 0.10 for microsphere flow;P< 0.01). Thus after 1 h relative thallium-201 (subendocardium LAD/remote, 0.96 ± 0.16) overestimated relative perfusion (0.78 ± 0.32;P< 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.