Diesel exhaust inhalation does not affect heart rhythm or heart rate variability.
OBJECTIVE
Exposure to air pollution is associated with increases in cardiovascular morbidity and mortality. This study was undertaken to determine the effect of diesel exhaust inhalation on heart rhythm and heart rate variability in healthy volunteers and patients with coronary heart disease.


METHODS
Double-blind randomised crossover studies in a university teaching hospital.


METHODS
32 healthy non-smoking volunteers and 20 patients with prior myocardial infarction.


METHODS
All 52 subjects were exposed for 1 h to dilute diesel exhaust (particle concentration 300 μg/m³) or filtered air.


METHODS
Heart rhythm and heart rate variability were monitored during and for 24 h after the exposure using continuous ambulatory electrocardiography and assessed using standard time and frequency domain analysis.


RESULTS
No significant arrhythmias occurred during or following exposures. Patients with coronary heart disease had reduced autonomic function in comparison to healthy volunteers, with reduced standard deviations of the NN interval (SDNN, p < 0.001) and triangular index (p < 0.001). Diesel exhaust did not affect heart rate variability compared with filtered air (p > 0.05 for all) in healthy volunteers (SDNN 101 ± 6 vs 91 ± 6, triangular index 20 ± 1 vs 21 ± 1) or patients with coronary heart disease (SDNN 47 ± 5 vs 38 ± 4, triangular index 8 ± 1 vs 7 ± 1).


CONCLUSIONS
Brief exposure to dilute diesel exhaust does not alter heart rhythm or heart rate variability in healthy volunteers or well-treated patients with stable coronary heart disease. Autonomic dysfunction does not appear to be a dominant mechanism that can explain the observed excess in cardiovascular events following exposure to combustion-derived air pollution.
Centre for Cardiovascular Science, The University of Edinburgh, Edinburgh, UK. nick.mills@ed.ac.uk
Nicholas L
NL
Mills
Alexander E
AE
Finlayson
Manuel C
MC
Gonzalez
Håkan
H
Törnqvist
Stefan
S
Barath
Elen
E
Vink
Colin
C
Goudie
Jeremy P
JP
Langrish
Stefan
S
Söderberg
Nicholas A
NA
Boon
Keith A A
KA
Fox
Ken
K
Donaldson
Thomas
T
Sandström
Anders
A
Blomberg
David E
DE
Newby
D000328:Adult; D000368:Aged; D001145:Arrhythmias, Cardiac / Q000209:etiology; D003327:Coronary Disease / Q000503:physiopathology; D018592:Cross-Over Studies; D004311:Double-Blind Method; D015716:Electrocardiography, Ambulatory / Q000379:methods; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D019570:Inhalation Exposure / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D052638:Particulate Matter / Q000494:pharmacology / Q000633:toxicity; D001335:Vehicle Emissions / Q000633:toxicity*; D055815:Young Adult
D052638:Particulate Matter; D001335:Vehicle Emissions