Secondhand Smoke Linked to Impaired Heart Function
NEW YORK (Reuters Health) - Inhaling secondhand smoke for as little as 2 hours can cause changes in heart function that are associated with heart attack risk, new study findings indicate.
While secondhand smoke is a known risk factor for heart disease, exactly how it affects the heart has remained unclear. Now, researchers report that heart rate variability (HRV) was reduced in healthy, nonsmoking individuals who spent time in a glass-enclosed smoking area.
HRV is a marker of how effectively an individual responds to stress and different activity levels. It is measured through heart rate and other automatic functions performed by the heart. One theory holds that the heart's failure to respond quickly to changes, such as a higher concentration of pollutants in the air, may be associated with poor long-term health.
``The most significant finding of our research is that we have observed that a relatively low concentration of tobacco smoke particles is associated with declines in heart function that may lead to adverse cardiac events,'' said lead investigator Dr. C. Arden Pope III of Brigham Young University in Provo, Utah.
The study included 16 nonsmokers aged 21 to 76 years who sat in a glass-enclosed smoking area at an international airport and a smoke-free lounge for 2-hour intervals. Researchers monitored the individuals' blood oxygen levels and heart rate variability while study volunteers sat, stood, ate and used the bathroom.
The findings, published in the online version of Environmental Health Perspectives for July, support other recent studies showing that even brief exposure to secondhand smoke can affect markers of heart disease risk.
According to one report, 30 minutes of secondhand smoke exposure resulted in a slowdown in blood flow among a group of nonsmokers. Another study found that smoking just one cigarette caused sudden changes in the function of the heart's key pumping chamber.