Document Detail


Norepinephrine spillover during exercise as a novel parameter to evaluate the severity of heart failure.
MedLine Citation:
PMID:  20503121     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND: The washout rate (WR) of (123)I-metaiodobenzylguanidine (MIBG) is now widely used for assessing the severity of heart failure. Although the WR of MIBG is usually measured at rest, the assessment of WR of MIBG during exercise might have a different clinical relevance. In this study, we measured the WR rate of MIBG during low-grade exercise and studied the clinical importance of this novel index.
METHODS: Twenty-four patients with dilated cardiomyopathy (DCM) were enrolled in this study. Planar images were obtained 20 minutes after MIBG injection (first image) and after 270 minutes (second image); the third image was obtained after 15 minutes of low-grade (10 W) bicycle ergometer exercise (300 minutes after MIBG injection). The decay of the specific counts was calculated from the first two images. The estimated third counts were calculated from the resting decay and were compared with the actual third counts.
RESULTS: In the receiver operating characteristic (ROC) curve analysis, we set a 10% decrease from the estimated counts as a cut-off value for severe heart failure (New York Heart Association [NYHA] Class IIm or worse). In 15 patients, the actual third count value was within 10% of the estimated count (N-group). In nine patients, the WR during exercise was high, and the actual third count values showed more than a 10% decrease from the estimated count value (H-group). In the H-group, 78% of the patients were in NYHA class IIm or III. In contrast, in the N-group, no patient had NYHA class III, and only 20% of the patients were in class IIm. The brain natriuretic peptide (BNP) level was significantly higher in the H-group than in the N-group (525 ± 263 pg/mL vs 176 ± 144 pg/mL; P < .01). No significant differences were observed in heart/mediastinal (H/M) activity ratio, the regular WR, and left ventricular ejection fraction values between the two groups.
CONCLUSIONS: The WR of MIBG during exercise may be an independent prediction variable, with a clinical relevance different from that of the WR at rest. This measurement could be used as a new index for assessing the severity of heart failure.
Authors:
Miyuki Ando; Takeshi Yamamoto; Akihiro Hino; Takashi Sato; Yasuma Nakamura; Masunori Matsuzaki
Publication Detail:
Type:  Journal Article     Date:  2010-05-26
Journal Detail:
Title:  Journal of nuclear cardiology : official publication of the American Society of Nuclear Cardiology     Volume:  17     ISSN:  1532-6551     ISO Abbreviation:  J Nucl Cardiol     Publication Date:  2010 Oct 
Date Detail:
Created Date:  2010-09-16     Completed Date:  2011-01-11     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  9423534     Medline TA:  J Nucl Cardiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  868-73     Citation Subset:  IM    
Affiliation:
Department of Medicine and Clinical Science, Yamaguchi University Graduate School of Medicine, 1-1-1 Minamikogushi, Ube 755-8505, Japan.
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MeSH Terms
Descriptor/Qualifier:
3-Iodobenzylguanidine / diagnostic use,  pharmacokinetics*
Adult
Aged
Exercise*
Female
Heart Failure / metabolism*,  radionuclide imaging
Humans
Male
Middle Aged
Norepinephrine / metabolism*
Radiopharmaceuticals / pharmacokinetics*
Chemical
Reg. No./Substance:
0/Radiopharmaceuticals; 51-41-2/Norepinephrine; 77679-27-7/3-Iodobenzylguanidine

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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