持续性室性心动过速与慢性恰加斯心肌病中用 123I-间碘苄胍评估的区域性心肌交感神经去神经支配有关。

Sustained ventricular tachycardia is associated with regional myocardial sympathetic denervation assessed with 123I-metaiodobenzylguanidine in chronic Chagas cardiomyopathy.

机构信息

Division of Cardiology, Department of Internal Medicine, University Hospital, Medical School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.

出版信息

J Nucl Med. 2011 Apr;52(4):504-10. doi: 10.2967/jnumed.110.082032.

DOI:10.2967/jnumed.110.082032

PMID:21441532

Abstract

UNLABELLED

Cardiac sympathetic denervation and ventricular arrhythmia are frequently observed in chronic Chagas cardiomyopathy (CCC). This study quantitatively evaluated the association between cardiac sympathetic denervation and sustained ventricular tachycardia (SVT) in patients with CCC.

METHODS

We prospectively investigated patients with CCC and left ventricular ejection fraction (LVEF) greater than 35% with SVT (SVT group: n = 15; mean age ± SD, 61 ± 8 y; LVEF, 51% ± 8%) and patients without SVT (non-SVT group: n = 11; mean age ± SD, 55 ± 10 y; LVEF, 57% ± 10%). Patients underwent myocardial scintigraphy with (123)I-metaiodobenzylguanidine ((123)I-MIBG) for the evaluation of sympathetic innervation and resting perfusion with (99m)Tc-methoxyisobutylisonitrile ((99m)Tc-MIBI) for the evaluation of myocardial viability. A visual semiquantitative score was attributed for regional uptake of each radiotracer using a 17-segment left ventricular segmentation model (0, normal; 4, absence of uptake). A mismatch defect was defined as occurring in segments with a (99m)Tc-MIBI uptake score of 0 or 1 and a (123)I-MIBG score of 2 or more.

RESULTS

Compared with the non-SVT group, the SVT group had a similar (99m)Tc-MIBI summed score (6.9 ± 7.5 vs. 4.4 ± 5.2, respectively, P = 0.69) but a higher (123)I-MIBG summed score (10.9 ± 7.8 vs. 22.4 ± 9.5, respectively, P = 0.007) and a higher number of mismatch defects per patient (2.0 ± 2.2 vs. 7.1 ± 2.0, respectively, P < 0.0001). The presence of more than 3 mismatch defects was strongly associated with the presence of SVT (93% sensitivity, 82% specificity; P = 0.0002).

CONCLUSION

In CCC, the amount of sympathetically denervated viable myocardium is associated with the occurrence of SVT. Myocardial sympathetic denervation may participate in triggering malignant ventricular arrhythmia in CCC patients with relatively well-preserved ventricular function.

摘要

目的

本研究旨在定量评估慢性 Chagas 心肌病（CCC）患者心脏去交感神经与持续性室性心动过速（SVT）之间的关系。

方法

我们前瞻性地研究了 15 例伴有 SVT（SVT 组：年龄均数±标准差，61±8 岁；左心室射血分数（LVEF），51%±8%）和 11 例无 SVT（非 SVT 组：年龄均数±标准差，55±10 岁；LVEF，57%±10%）的 CCC 患者。所有患者均接受（123）I-间位碘代苄胍（（123）I-MIBG）心肌闪烁显像以评估交感神经支配情况，并用（99m）Tc-甲氧基异丁基异腈（（99m）Tc-MIBI）进行静息灌注显像以评估心肌存活情况。使用 17 节段左心室分段模型对两种放射性示踪剂的局部摄取情况进行视觉半定量评分（0 分为正常，4 分为无摄取）。定义摄取缺损为（99m）Tc-MIBI 摄取评分 0 或 1 与（123）I-MIBG 评分 2 或更高的节段。

结果

与非 SVT 组相比，SVT 组的（99m）Tc-MIBI 总和评分相似（分别为 6.9±7.5 和 4.4±5.2，P=0.69），但（123）I-MIBG 总和评分较高（分别为 10.9±7.8 和 22.4±9.5，P=0.007），且每位患者的摄取缺损数较多（分别为 2.0±2.2 和 7.1±2.0，P<0.0001）。存在超过 3 个摄取缺损与 SVT 的存在密切相关（敏感性 93%，特异性 82%；P=0.0002）。