title: Cardiac sympathetic nervous disintegrity is related to exercise intolerance in patients with chronic heart failure.
abstract: 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.
authors.affiliation: First Department of Internal Medicine, Yamagata University School of Medicine, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Atsumi
authors.forename: Y
authors.initials: Y
authors.lastname: Takeishi
authors.forename: S
authors.initials: S
authors.lastname: Fujiwara
authors.forename: H
authors.initials: H
authors.lastname: Tomoike
mesh_terms: D019797:3-Iodobenzylguanidine; D001342:Autonomic Nervous System Diseases / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D001794:Blood Pressure / Q000502:physiology; D002908:Chronic Disease; D005080:Exercise Test; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D006333:Heart Failure / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009638:Norepinephrine / Q000097:blood; D010101:Oxygen Consumption; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D013564:Sympathetic Nervous System / Q000000981:diagnostic imaging* / Q000503:physiopathology*
chemical_list: D019275:Radiopharmaceuticals; D019797:3-Iodobenzylguanidine; D009638:Norepinephrine