Atsumi H, Takeishi Y, Fujiwara S, Tomoike H
First Department of Internal Medicine, Yamagata University School of Medicine, Japan.
Nucl Med Commun. 1998 May;19(5):451-6. doi: 10.1097/00006231-199805000-00007.
The aim of this study was to clarify the relationship between cardiac sympathetic nervous activity assessed by 123I-MIBG imaging and exercise capacity in patients with congestive heart failure. The subjects were 24 patients with heart failure (NYHA class II to III) and 7 normal controls. A dose of 148 MBq of 123I-MIBG was administered intravenously, and 5-min anterior planar images were obtained 20 min (early) and 4 h (delayed) after the injection of 123I-MIBG. Regions of interest were placed over the left ventricle and mediastinum, and the heart-to-mediastinum ratio (H/M ratio) was calculated as a fraction of the mean counts per pixel in the heart divided by those in the mediastinum. The washout rate from the myocardium was determined by: (early counts delayed counts) x 100/early counts (%). Treadmill exercise tests were performed using a ramp method within 1 week of the 123I-MIBG studies. During exercise, expired gas was analysed, and peak VO2 and VO2 at the anaerobic threshold (ATVO2) were measured. A significant linear correlation was found between the H/M ratio on delayed 123I-MIBG images and exercise duration (r = 0.48, P < 0.05), peak VO2 (r = 0.49, P < 0.05) and ATVO2 (r = 0.56, P < 0.01). The washout rate of 123I-MIBG was inversely correlated with exercise duration (r = -0.45, P < 0.05), peak VO2 (r = -0.51, P < 0.01), and ATVO2 (r = -0.50, P < 0.05). In conclusion, enhanced cardiac sympathetic nervous activity relates to exercise intolerance in patients with congestive heart failure. The non-invasive assessment of cardiac sympathetic nervous activity by 123I-MIBG can predict exercise capacity in human heart failure.
本研究旨在阐明通过123I-间碘苄胍（MIBG）显像评估的心脏交感神经活动与充血性心力衰竭患者运动能力之间的关系。研究对象为24例心力衰竭患者（纽约心脏协会心功能分级II至III级）和7名正常对照者。静脉注射148 MBq的123I-MIBG，在注射123I-MIBG后20分钟（早期）和4小时（延迟期）获取5分钟的前位平面图像。在左心室和纵隔放置感兴趣区，并计算心脏与纵隔比值（H/M比值），计算方法为心脏内每像素平均计数除以纵隔内每像素平均计数。心肌的清除率通过以下公式确定：（早期计数 - 延迟期计数）×100/早期计数（%）。在123I-MIBG研究的1周内，采用斜坡法进行平板运动试验。运动期间，分析呼出气体，并测量峰值摄氧量（VO2）和无氧阈时的VO2（ATVO2）。在延迟期123I-MIBG图像上的H/M比值与运动持续时间（r = 0.48，P < 0.05）、峰值VO2（r = 0.49，P < 0.05）和ATVO2（r = 0.56，P < 0.01）之间发现显著的线性相关性。123I-MIBG的清除率与运动持续时间（r = -0.45，P < 0.05）、峰值VO2（r = -0.51，P < 0.01）和ATVO2（r = -0.50，P < 0.05）呈负相关。总之，心脏交感神经活动增强与充血性心力衰竭患者运动不耐受有关。通过123I-MIBG对心脏交感神经活动进行无创评估可预测人类心力衰竭患者的运动能力。
