Allman K C, Stevens M J, Wieland D M, Hutchins G D, Wolfe E R, Greene D A, Schwaiger M
Department of Internal Medicine, University of Michigan, Ann Arbor.
J Am Coll Cardiol. 1993 Nov 1;22(5):1425-32. doi: 10.1016/0735-1097(93)90553-d.
The purpose of this investigation was to evaluate the sympathetic nervous system of the heart by positron emission tomographic (PET) imaging in patients with diabetes mellitus with and without diabetic autonomic neuropathy.
The clinical assessment of cardiac involvement in diabetic autonomic neuropathy has been limited to cardiovascular reflex testing. With the recent introduction of radiolabeled catecholamines such as carbon (C)-11 hydroxyephedrine, the sympathetic innervation of the heart can be specifically visualized with PET imaging.
Positron emission tomographic imaging was performed with C-11 hydroxyephedrine and rest myocardial blood flow imaging with nitrogen-13 ammonia. Three patient groups were studied, including healthy volunteers as control subjects, diabetic patients with normal autonomic function testing and diabetic patients with varying severity of autonomic neuropathy. Homogeneity of cardiac tracer retention as well as absolute tracer retention was determined by relating myocardial tracer retention to an arterial C-11 activity input function.
Abnormal regional C-11 hydroxyephedrine retention was seen in seven of eight patients with autonomic neuropathy. Relative tracer retention was significantly reduced in apical, inferior and lateral segments. The extent of the abnormality correlated with the severity of conventional markers of autonomic dysfunction. Absolute myocardial tracer retention index measurements showed a 45 +/- 21% decrease in distal compared with proximal myocardial segments in autonomic neuropathy (0.069 +/- 0.037 min-1 vs. 0.13 +/- 0.052 min-1, p = 0.02).
This study demonstrates a heterogeneous pattern of neuronal abnormalities in patients with diabetic cardiac neuropathy. The extent of this abnormality correlated with the severity of neuropathy assessed by conventional tests. Future studies in larger groups of patients are required to define the relative sensitivity of this imaging approach in detecting cardiac neuropathy and to determine the clinical significance of these scintigraphic findings in comparison with conventional markers of autonomic innervation.
本研究旨在通过正电子发射断层扫描（PET）成像评估伴有或不伴有糖尿病自主神经病变的糖尿病患者心脏的交感神经系统。
糖尿病自主神经病变中心脏受累的临床评估一直局限于心血管反射测试。随着近期如碳（C）-11羟基麻黄碱等放射性标记儿茶酚胺的引入，心脏的交感神经支配可通过PET成像进行特异性可视化。
使用C-11羟基麻黄碱进行正电子发射断层扫描成像，并使用氮-13氨进行静息心肌血流成像。研究了三组患者，包括作为对照的健康志愿者、自主神经功能测试正常的糖尿病患者以及自主神经病变严重程度不同的糖尿病患者。通过将心肌示踪剂滞留与动脉C-11活性输入函数相关联，确定心脏示踪剂滞留的均匀性以及绝对示踪剂滞留。
8例自主神经病变患者中有7例出现局部C-11羟基麻黄碱滞留异常。心尖、下壁和侧壁节段的相对示踪剂滞留显著降低。异常程度与自主神经功能障碍的传统标志物的严重程度相关。绝对心肌示踪剂滞留指数测量显示，自主神经病变患者远端心肌节段与近端心肌节段相比下降了45±21%（0.069±0.037 min-1对0.13±0.052 min-1，p = 0.02）。
本研究证明糖尿病性心脏神经病变患者存在神经元异常的异质性模式。这种异常的程度与通过传统测试评估的神经病变严重程度相关。需要对更多患者进行进一步研究，以确定这种成像方法在检测心脏神经病变方面的相对敏感性，并确定这些闪烁显像结果与自主神经支配的传统标志物相比的临床意义。
