title: Ambient carbon monoxide may influence heart rate variability in subjects with coronary artery disease.
abstract: OBJECTIVE
  Days of high ambient carbon dioxide (CO) have been associated with increased hospital admissions for cardiac disease. This study was conducted to determine if daily concentrations of CO and fine particulates (PM2.5) are associated with daily changes in heart rate variability.
  
  
  METHODS
  Each of 36 adults with coronary artery disease had personal exposure to PM2.5 and CO measured along with heart rate variability for one 24-hour period each week for up to 10 weeks.
  
  
  RESULTS
  Among those not taking beta-receptor blockers, there was a positive association between the standard deviation of the R-to-R intervals and CO (P = 0.02). No effect was found for PM2.5.
  
  
  CONCLUSIONS
  Urban exposure to CO may exert a biologic effect on the heart, which may be modified by medications.
authors.affiliation: HECSB/SEP/ECB/AHED/AQHER, Ottawa, Health Canada Air Quality-Health Effects Research Section, Health Canada, 275 Slater Street, 7th Floor, Ottawa, Ontario, Canada K1A 0L2. rdales@ohri.ca
authors.forename: Robert
authors.initials: R
authors.lastname: Dales
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000368:Aged; D000369:Aged, 80 and over; D000787:Angina Pectoris / Q000188:drug therapy / Q000453:epidemiology; D002248:Carbon Monoxide / Q000032:analysis / Q000633:toxicity*; D015897:Comorbidity; D003324:Coronary Artery Disease / Q000188:drug therapy / Q000453:epidemiology / Q000503:physiopathology*; D004781:Environmental Exposure / Q000032:analysis* / Q000706:statistics & numerical data; D004784:Environmental Monitoring / Q000706:statistics & numerical data; D062665:Epidemiological Monitoring; D005260:Female; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009864:Ontario / Q000453:epidemiology
chemical_list: D000319:Adrenergic beta-Antagonists; D002248:Carbon Monoxide