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- Barath, Stefan, 1963-, et al.
(författare)
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Short-Term Exposure to Ozone Does Not Impair Vascular Function or Affect Heart Rate Variability in Healthy Young Men
- 2013
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Ingår i: Toxicological Sciences. - : Oxford University Press. - 1096-6080 .- 1096-0929. ; 135:2, s. 292-299
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Tidskriftsartikel (refereegranskat)abstract
- Air pollution exposure is associated with cardiovascular morbidity and mortality, yet the role of individual pollutants remains unclear. In particular, there is uncertainty regarding the acute effect of ozone exposure on cardiovascular disease. In these studies, we aimed to determine the effect of ozone exposure on vascular function, fibrinolysis, and the autonomic regulation of the heart. Thirty-six healthy men were exposed to ozone (300 ppb) and filtered air for 75min on two occasions in randomized double-blind crossover studies. Bilateral forearm blood flow (FBF) was measured using forearm venous occlusion plethysmography before and during intra-arterial infusions of vasodilators 2–4 and 6–8h after each exposure. Heart rhythm and heart rate variability (HRV) were monitored during and 24h after exposure. Compared with filtered air, ozone exposure did not alter heart rate, blood pressure, or resting FBF at either 2 or 6h. There was a dose-dependent increase in FBF with all vasodilators that was similar after both exposures at 2–4h. Ozone exposure did not impair vasomotor or fibrinolytic function at 6–8h but rather increased vasodilatation to acetylcholine (p = .015) and sodium nitroprusside (p = .005). Ozone did not affect measures of HRV during or after the exposure. Our findings do not support a direct rapid effect of ozone on vascular function or cardiac autonomic control although we cannot exclude an effect of chronic exposure or an interaction between ozone and alternative air pollutants that may be responsible for the adverse cardiovascular health effects attributed to ozone.
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| 2. |
- Mills, Nicholas L, et al.
(författare)
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Diesel exhaust inhalation does not affect heart rhythm or heart rate variability
- 2011
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Ingår i: Heart. - : BMJ. - 1355-6037 .- 1468-201X. ; 97:7, s. 544-550
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Tidskriftsartikel (refereegranskat)abstract
- 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.Design and setting Double-blind randomised crossover studies in a university teaching hospital.Patients 32 healthy non-smoking volunteers and 20 patients with prior myocardial infarction.Interventions All 52 subjects were exposed for 1 h to dilute diesel exhaust (particle concentration 300 μg/m(3)) or filtered air.Main outcome measures 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.
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