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Iodine 123‐metaiodobenzylguanidine imaging reflect generalized sympathetic activation in patients with left ventricular dysfunction
Author(s) -
Yuyama Reisuke,
Yuasa Fumio,
Hikosaka Makoto,
Mimura Jun,
Kawamura Akihiro,
Hatada Kengo,
Motohiro Masayuki,
Iwasaki Masayoshi,
Sugiura Tetsuro,
Iwasaka Toshiji
Publication year - 2005
Publication title -
clinical physiology and functional imaging
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.608
H-Index - 67
eISSN - 1475-097X
pISSN - 1475-0961
DOI - 10.1111/j.1475-097x.2004.00571.x
Subject(s) - medicine , cardiology , microneurography , myocardial infarction , heart rate , scintigraphy , norepinephrine , ejection fraction , washout , sympathetic nervous system , heart failure , nuclear medicine , blood pressure , dopamine , baroreflex
Summary Background: Iodine 123‐metaiodobenzylguanidine (MIBG) imaging has been used to assess cardiac sympathetic nerve abnormalities. To determine the role of MIBG imaging as a measure of generalized sympathetic nerve activity, MIBG imaging was evaluated with muscle sympathetic nerve activity (MSNA) and plasma norepinephrine (noradrenaline) level in patients with old myocardial infarction. Methods: Myocardial MIBG scintigraphy, MSNA and plasma norepinephrine measurement were performed within 3 days in 35 patients with old myocardial infarction. Patients were divided into three groups according to their ejection fraction (EF); preserved (EF ≥ 50%, 12 patients), intermediate (35% < EF < 50%, 13 patients), or depressed (EF ≤ 35%, 10 patients).The heart to mediastinum (H/M) ratio was obtained 4 h after tracer injection from the chest anterior view image. MIBG washout rate was calculated from the early and delayed images. MSNA was recorded by microneurography. Results: Plasma norepinephrine level had weak negative correlations with early H/M ratio ( r = 0·37, P <0·05) and delayed H/M ratio ( r = 0·33, P <0·05), and a positive correlation with MIBG washout rate ( r = 0·54, P <0·01). MSNA had weak negative correlations with early H/M ratio ( r = 0·51, P <0·05) and delayed H/M ratio ( r = 0·52, P <0·05). However, a strong correlation was found between MSNA and MIBG washout rate ( r = 0·88, P <0·001). Despite no significant differences in plasma norepinephrine level and H/M ratio, patients with intermediate and depressed EF had higher MIBG washout rate and MSNA compared with those with preserved EF. Conclusions: Increased in cardiac sympathetic nerve activity was associated with augmented sympathetic outflow of the skeletal muscle and hence, MIBG washout rate allow the assessment of general sympathetic nerve activity.