Document Detail


ECG parameters and exposure to carbon ultrafine particles in young healthy subjects.
MedLine Citation:
PMID:  18991063     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The mechanisms underlying the association between air pollution and cardiovascular morbidity and mortality are unknown. This study aimed to determine whether controlled exposure to elemental carbon ultrafine particles (UFP) affects electrocardiogram (ECG) parameters describing heart rate variability; repolarization duration, morphology, and variability; and changes in the ST segment. Two separate controlled studies (12 subjects each) were performed using a crossover design, in which each subject was exposed to filtered air and carbon UFP for 2 hours. The first protocol involved 2 exposures to air and 10 microg/m(3) (approximately 2 x 10(6) particles/cm(3), count median diameter approximately 25 nm, geometric standard deviation approximately 1.6), at rest. The second protocol included 3 exposures to air, 10, and 25 microg/m(3) UFP (approximately 7 x 10(6) particles/cm(3)), with repeated exercise. Each subject underwent a continuous digital 12-lead ECG Holter recording to analyze the above ECG parameters. Repeated measures analysis of variance (ANOVA) was used to compare tested parameters between exposures. The observed responses to UFP exposure were small and generally not significant, although there were trends indicating an increase in parasympathetic tone, which is most likely also responsible for trends toward ST elevation, blunted QTc shortening, and increased variability of T-wave complexity after exposure to UFP. Recovery from exercise showed a blunted response of the parasympathetic system after exposure to UFP in comparison to air exposure. In conclusion, transient exposure to 10-25 microg/m(3) ultrafine carbon particles does not cause marked changes in ECG-derived parameters in young healthy subjects. However, trends are observed indicating that some subjects might be susceptible to air pollution, with a response involving autonomic modulation of the heart and repolarization of the ventricular myocardium.
Authors:
Wojciech Zareba; Jean Philippe Couderc; Günter Oberdörster; David Chalupa; Christopher Cox; Li-Shan Huang; Annette Peters; Mark J Utell; Mark W Frampton
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Publication Detail:
Type:  Journal Article; Randomized Controlled Trial; Research Support, N.I.H., Extramural; Research Support, U.S. Gov't, Non-P.H.S.    
Journal Detail:
Title:  Inhalation toxicology     Volume:  21     ISSN:  1091-7691     ISO Abbreviation:  Inhal Toxicol     Publication Date:  2009 Feb 
Date Detail:
Created Date:  2009-02-04     Completed Date:  2009-04-22     Revised Date:  2014-09-15    
Medline Journal Info:
Nlm Unique ID:  8910739     Medline TA:  Inhal Toxicol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  223-33     Citation Subset:  IM    
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MeSH Terms
Descriptor/Qualifier:
Adult
Carbon / adverse effects*,  chemistry
Cross-Over Studies
Double-Blind Method
Electrocardiography, Ambulatory*
Environmental Exposure*
Exercise
Female
Heart Rate
Humans
Male
Particle Size
Silicones
Young Adult
Grant Support
ID/Acronym/Agency:
P30 ES 01247/ES/NIEHS NIH HHS; R01 ES 13394/ES/NIEHS NIH HHS; R01 ES011853/ES/NIEHS NIH HHS; R01 ES011853-04/ES/NIEHS NIH HHS; R01 ES013394/ES/NIEHS NIH HHS; R01 ES013394-01/ES/NIEHS NIH HHS; RR 00044/RR/NCRR NIH HHS; T32 HL066988/HL/NHLBI NIH HHS
Chemical
Reg. No./Substance:
0/Silicones; 7440-44-0/Carbon; 94363-16-3/Ultrafine
Comments/Corrections

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