Open Access Research

Changes in deceleration capacity of heart rate and heart rate variability induced by ambient air pollution in individuals with coronary artery disease

Alexandra Schneider1*, Regina Hampel1, Angela Ibald-Mulli2, Wojciech Zareba3, Georg Schmidt4, Raphael Schneider4,5, Regina Rückerl1, Jean P Couderc3, Betty Mykins3, Günter Oberdörster6, Gabriele Wölke1, Mike Pitz7, H -Erich Wichmann1,2 and Annette Peters1,8

Author Affiliations

1 Helmholtz Zentrum München, German Research Center for Environmental Health, Institute of Epidemiology, Neuherberg, Germany

2 IBE Department of Epidemiology, Ludwig-Maximilians-University of Munich, Munich, Germany

3 Cardiology Division, University of Rochester Medical Center, Rochester, NY, USA

4 First Medical Clinic, Munich University of technology and German Heart Center Munich, Munich, Germany

5 Medtronic Bakken Research Center, Maastricht, The Netherlands

6 Department of Environmental Medicine, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA

7 University of Augsburg, Environmental Science Center, Augsburg, Germany

8 Focus Network Nanoparticles and Health (NanoHealth), Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany

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Particle and Fibre Toxicology 2010, 7:29 doi:10.1186/1743-8977-7-29

Published: 7 October 2010

Abstract

Background and Objective

Exposure to ambient particles has been shown to be responsible for cardiovascular effects, especially in elderly with cardiovascular disease. The study assessed the association between deceleration capacity (DC) as well as heart rate variability (HRV) and ambient particulate matter (PM) in patients with coronary artery disease (CAD).

Methods

A prospective study with up to 12 repeated measurements was conducted in Erfurt, Germany, between October 2000 and April 2001 in 56 patients with physician-diagnosed ischemic heart disease, stable angina pectoris or prior myocardial infarction at an age of at least 50 years. Twenty-minute ECG recordings were obtained every two weeks and 24-hour ECG recordings every four weeks. Exposure to PM (size range from 10 nm to 2.5 μm), and elemental (EC) and organic (OC) carbon was measured. Additive mixed models were used to analyze the association between PM and ECG recordings.

Results

The short-term recordings showed decrements in the high-frequency component of HRV as well as in RMSSD (root-mean-square of successive differences of NN intervals) in association with increments in EC and OC 0-23 hours prior to the recordings. The long-term recordings revealed decreased RMSSD and pNN50 (% of adjacent NN intervals that differed more than 50 ms) in association with EC and OC 24-47 hours prior to the recordings. In addition, highly significant effects were found for DC which decreased in association with PM2.5, EC and OC concurrent with the ECG recordings as well as with a lag of up to 47 hours.

Conclusions

The analysis showed significant effects of ambient particulate air pollution on DC and HRV parameters reflecting parasympathetic modulation of the heart in patients with CAD. An air pollution-related decrease in parasympathetic tone as well as impaired heart rate deceleration capacity may contribute to an increased risk for cardiac morbidity and sudden cardiac death in vulnerable populations.