T-wave alternans, air pollution and traffic in high-risk subjects.
Particulate pollution has been linked to risk for cardiac death; possible mechanisms include pollution-related increases in cardiac electrical instability. T-wave alternans (TWA) is a marker of cardiac electrical instability measured as differences in the magnitude between adjacent T waves. In a repeated-measures study of 48 patients aged 43 to 75 years, associations of ambient and home indoor particulate pollution, including black carbon (BC) and reports of traffic exposure, with changes in 0.5-hourly maximum TWA (TWA-MAX), measured by 24-hour Holter electrocardiographic monitoring, were investigated. Each patient was observed up to 4 times within 1 year after percutaneous intervention for myocardial infarction, acute coronary syndromes without infarction, or stable coronary artery disease, for a total of 5,830 0.5-hour observations. Diary data for each 0.5-hour period defined whether a patient was home or not home, or in traffic. Increases in TWA-MAX were independently associated with the previous 2-hour mean ambient BC (2.1%, 95% confidence interval 0.9% to 3.3%) and with being in traffic in the previous 2 hours (6.1%, 95% confidence interval 3.4% to 8.8%). When subjects were home, indoor home BC effects were largest and most precise; when subjects were away from home, ambient central site BC effects were strongest. Increases in pollution increased the odds of TWA-MAX > or =75th percentile (odds ratio 1.4, 95% confidence interval 1.2 to 1.6 for a 1 microg/m(3) increase in 6-hour mean BC). In conclusion, after hospitalization for coronary artery disease, being in traffic and short-term ambient or indoor BC exposure increased TWA, a marker of cardiac electrical instability.
Zanobetti
Antonella
A
Exposure, Epidemiology and Risk Program, Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts, USA. azanobet@hsph.harvard.edu
Stone
Peter H
PH
Speizer
Frank E
FE
Schwartz
Joel D
JD
Coull
Brent A
BA
Suh
Helen H
HH
Nearing
Bruce D
BD
Mittleman
Murray A
MA
Verrier
Richard L
RL
Gold
Diane R
DR
D054058:Acute Coronary Syndrome / Q000503:physiopathology / Q000628:therapy; D000328:Adult; D000368:Aged; D000397:Air Pollution; D016902:Air Pollution, Indoor; D000789:Angina, Unstable / Q000503:physiopathology / Q000628:therapy; D015906:Angioplasty, Balloon, Coronary; D001334:Automobile Driving; D015716:Electrocardiography, Ambulatory; D005260:Female; D006329:Heart Conduction System / Q000503:physiopathology*; D006801:Humans; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000503:physiopathology* / Q000628:therapy
J Cardiovasc Electrophysiol. 2003 Jul;14(7):705-11
12930249
Am J Respir Crit Care Med. 2007 Aug 15;176(4):370-6
17463411
Circulation. 2008 Sep 23;118(13):1314-20
18779445
J Appl Physiol (1985). 2002 Feb;92(2):541-9
11796662
Environ Health Perspect. 2005 Mar;113(3):304-9
15743719
Mutat Res. 2007 Aug 1;621(1-2):50-60
17603085
Circulation. 1987 Jan;75(1):131-8
3791599
Heart Rhythm. 2009 Mar;6(3):416-22
19251221
Environ Health Perspect. 2005 Apr;113(4):440-6
15811835
Circulation. 2000 Mar 21;101(11):1267-73
10725286
J Am Coll Cardiol. 2007 Dec 4;50(23):2233-40
18061071
Environ Health Perspect. 2007 Nov;115(11):1617-22
18007994
Thorax. 2005 Jun;60(6):455-61
15923244
Ann Noninvasive Electrocardiol. 2005 Jan;10(1):110-20
15649246
Environ Health Perspect. 2007 Apr;115(4):507-12
17450216
Circulation. 2007 Aug 14;116(7):e148-304
17679616
Epidemiology. 2008 Jan;19(1):121-8
18091421
Thorax. 2004 Mar;59(3):204-9
14985553
Part Fibre Toxicol. 2006 Sep 08;3:13
16961926
N Engl J Med. 2004 Oct 21;351(17):1721-30
15496621
Environ Health Perspect. 2005 Jul;113(7):883-7
16002377
Circ Res. 2002 Oct 18;91(8):727-32
12386150