Traffic Air Pollution Prompts Factors for Sudden Cardiac Death

Heart rate variability (HRV) is a measure of the heart's ability to adapt to changes in the environment, and reduced HRV can indicate weakened control of the heart by the autonomic nervous system. Helen H. Suh, from the Harvard School of Public Health (Massachusetts, USA), and colleagues studied 30 Atlanta-area residents with lung disease (chronic obstructive pulmonary disease) or heart disease (previous heart attack). While the team found no link between reduced heart rate variability and ambient levels of air pollutants in the areas where the participants lived, the portable monitoring devices worn by the patients showed a significant association between reduced HRV and personal exposure to traffic-related air pollutants, including elemental carbon and nitrogen dioxide. Adding to recent evidence of a link between short-term, personal exposure to traffic-related pollution and reduced HRV, this study finds that: “Decreased vagal tone [is indicated] in response to traffic pollutants.”