title: Myocardial iodine-123-metaiodobenzylguanidine images and autonomic nerve activity in normal subjects.
abstract: We studied the relationship between myocardial [123I]metaiodobenzylguanidine (MIBG) uptake and autonomic nerve activity in normal subjects.
  
  
  METHODS
  MIBG scintigraphy and power spectral analysis (PSA) of heart rate variability were performed simultaneously in 15 normal subjects. Anterior planar images and SPECT images were taken at five and two points after the injection of [123I]MIBG, respectively. In 10 of 15 subjects, 201TI myocardial SPECT was performed immediately after MIBG scintigraphy.
  
  
  RESULTS
  The heart/upper mediastinum MIBG uptake ratio in the planar image obtained at 240 min (r = 0.64, p < 0.01) and the washout rate of MIBG in the heart between 15 min and 240 min (r = 0.51, p < 0.05) showed significant correlation with the percentage of low frequency component of PSA (percent LF), an index of sympathetic nerve activity. Regional MIBG uptake in the inferior wall normalized by individual maximal uptake among all pixels was significantly correlated with the high frequency component of PSA, an index of parasympathetic nerve activity (r = -0.58, p < 0.05) and with mean R-R interval in a resting ECG (r = -0.82, p < 0.001) but did not correlate with percent LF, percent uptake of 201TI in the inferior wall or the liver/heart uptake ratio.
  
  
  CONCLUSIONS
  These results indicate that myocardial MIBG uptake correlates with sympathetic nerve activity in normal subjects. Our data indicate that heterogeneous MIBG distribution in the left ventricle is a physiologic rather than artifactual phenomenon and may be related to vagal tone rather than sympathetic nerve activity.
authors.affiliation: First Department of Medicine, Osaka University Medical School, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Morozumi
authors.forename: H
authors.initials: H
authors.lastname: Kusuoka
authors.forename: K
authors.initials: K
authors.lastname: Fukuchi
authors.forename: A
authors.initials: A
authors.lastname: Tani
authors.forename: T
authors.initials: T
authors.lastname: Uehara
authors.forename: S
authors.initials: S
authors.lastname: Matsuda
authors.forename: E
authors.initials: E
authors.lastname: Tsujimura
authors.forename: Y
authors.initials: Y
authors.lastname: Ito
authors.forename: M
authors.initials: M
authors.lastname: Hori
authors.forename: T
authors.initials: T
authors.lastname: Kamada
authors.forename: T
authors.initials: T
authors.lastname: Nishimura
mesh_terms: D019797:3-Iodobenzylguanidine; D000328:Adult; D003287:Contrast Media; D006321:Heart / Q000000981:diagnostic imaging* / Q000294:innervation; D006801:Humans; D007457:Iodine Radioisotopes / Q000493:pharmacokinetics*; D007462:Iodobenzenes / Q000493:pharmacokinetics*; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism*; D011877:Radionuclide Imaging; D014018:Tissue Distribution
chemical_list: D003287:Contrast Media; D007457:Iodine Radioisotopes; D007462:Iodobenzenes; D019797:3-Iodobenzylguanidine