Maeno M, Ishida Y, Shimonagata T, Hayashida K, Toyama T, Hirose Y, Nagata M, Miyatake K, Uehara T, Nishimura T
Osaka University.
Kaku Igaku. 1993 Oct;30(10):1221-9.
123I-MIBG (MIBG) regional defects in myocardial regions with preserved 201Tl (Tl) uptake have been observed in patients with idiopathic dilated cardiomyopathy (DCM). To evaluate whether the presence of Tl/MIBG mismatched regions is related to the occurrence of ventricular tachycardia (VT), we performed myocardial dual SPECT imaging with Tl (111 MBq) and MIBG (111 MBq) in 17 patients with DCM, 11 (Gp A) with and 6 (Gp B) without VT. Myocardial dual SPECT imaging was performed at 15 minutes after and 4 hours after the tracer injection. The regional tracer uptake was scored visually in 6 segments of the basal, middle, and apical short-axial images and in 2 apical segments of the midventricular vertical long-axial image by a four-point scoring system (0 = normal, 1 = moderate, 2 = severe and 3 = complete defect). Then, the severity of tracer maldistributions was assessed by the difference between total defect scores (TDSs) of Tl and MIBG (delta TDS). TDS was not different between Gps A and B in both Tl and MIBG images. However, delta TDS was larger in Gp A than in Gp B (13.5 +/- 6.5 vs. 5.8 +/- 3.0, p < 0.05). Also, the number of segments with the mismatched tracer uptake was larger in Gp A than in Gp B (12.5 +/- 3.0 vs. 8.3 +/- 1.5, p < 0.01). In the electrophysiologic study, we found that the fractionated area corresponded to the mismatched region in 3 of 5 patients in Gp A. These results suggest that regional sympathetic denervation is a possible factor which provocates VT, and myocardial dual SPECT imaging with Tl and MIBG is a useful method for predicting VT in patients with DCM.
在特发性扩张型心肌病（DCM）患者中，已观察到在201铊（Tl）摄取正常的心肌区域存在123I-间碘苄胍（MIBG）区域缺损。为了评估Tl/MIBG不匹配区域的存在是否与室性心动过速（VT）的发生有关，我们对17例DCM患者进行了Tl（111MBq）和MIBG（111MBq）心肌双核素单光子发射计算机断层显像（SPECT），其中11例（A组）有VT，6例（B组）无VT。在注射示踪剂后15分钟和4小时进行心肌双核素SPECT显像。通过四点评分系统（0 = 正常，1 = 中度，2 = 重度，3 = 完全缺损）对基底、中间和心尖短轴图像的6个节段以及心室中部垂直长轴图像的2个心尖节段的局部示踪剂摄取进行视觉评分。然后，通过Tl和MIBG的总缺损评分（TDS）之差（δTDS）评估示踪剂分布不均的严重程度。在Tl和MIBG图像中，A组和B组的TDS无差异。然而，A组的δTDS大于B组（13.5±6.5对5.8±3.0，p<0.05）。此外，示踪剂摄取不匹配节段的数量A组多于B组（12.5±3.0对8.3±1.5，p<0.01）。在电生理研究中，我们发现A组5例患者中有3例的碎裂区域与不匹配区域相对应。这些结果表明，局部交感神经去神经支配是诱发VT的一个可能因素，Tl和MIBG心肌双核素SPECT显像是预测DCM患者VT的一种有用方法。
