Air pollution could be putting patients with heart disease at risk by affecting blood vessels and clotting, researchers warn.
A study by the University of Edinburgh and Ume University measured the effects of diesel exhaust on heart and blood vessel function in men who have previously experienced a heart attack.
The research, funded by the British Heart Foundation and published in the New England Journal of Medicine, found that inhalation of diesel exhaust caused changes in the hearts electrical activity, suggesting that air pollution reduces the amount of oxygen available to the heart during exercise.
Dr Nicholas Mills, of the University?s Centre for Cardiovascular Sciences, said: This study provides an explanation for why patients with heart disease are more likely to be admitted to hospital on days in which air pollution levels are increased. Most people tend to think of air pollution as having effects on the lungs but, as this study shows, it can also have a major impact on how our heart functions.
Twenty men who had suffered a previous heart attack were carefully screened to ensure they did not suffer from angina or heart rhythm problems and that their heart condition was stable and appropriately treated. The men were exposed for one hour to either filtered air or dilute diesel exhaust while intermittently riding a stationary bicycle in a carefully monitored exposure chamber in Ume University. Heart function was monitored continuously and blood tests taken six hours after leaving the chamber.
Electrical monitoring of the heart showed that inhalation of diesel exhaust caused a three-fold increase in the stress of the heart during exercise. In addition, the bodys ability to release a ?guardian protein known as t-PA (tissue plasminogen activator), which can prevent blood clots from forming, was also reduced by more than one third following exposure.
The link between air pollution and heart disease is
|Contact: Tara Womersley|
University of Edinburgh