Breathing particulate matter (i.e., tiny particles suspended in the air) air pollution may trigger irregular heart rhythms (arrhythmias) in healthy teenagers, according to new research published today in the Journal of the American Heart Association.
The study examined the impact of breathing fine particulate matter on heart rhythms of adolescents. Fine particulates (PM2.5) are less than 2.5 microns in size and can easily be inhaled deep into the lungs and even enter the bloodstream. Once inhaled, the pollutants irritate the lungs and blood vessels around the heart, and previous research has suggested that over time, pollutants increase the process of disease in the arteries.
The investigators analyzed the impact of breathing particulate matter pollution on two types of irregular heart rhythms characterized by premature contraction in the heart muscle, often described as a "skipped heart beat."
If premature contractions cause no symptoms, they are not treated. However, if they occur often and lead to frequently feeling a skipped heartbeat, fast heartbeat or a pounding heart, treatment with medications, implantable devices or procedures may be advised.
Researchers analyzed health data for 322 adolescents living in central Pennsylvania who participated in a follow-up evaluation in the Penn State Child Cohort study. That study, conducted between 2002 and 2006, initially recruited children ages 6 to 12 years. The data analyzed in this study reviewed results from the follow-up evaluation nearly 7.5 years later (2010-2013). This group of children were free of major cardiovascular conditions and considered at low risk for irregular heart rhythms. In the follow-up study, the researchers simultaneously measured exposure to fine particulate matter in the air each teen breathed (using a device called a nephelometer) for 24 hours and EKG tracings of each teen's heart rhythms via a small wearable device called a Holter monitor.
The study found:
79% of the participants had at least one irregular heart rhythm during the 24-hour study period. Of that group, 40% had only premature atrial contractions, 12% had only premature ventricular contractions, and 48% had both.
A 5% increase in the number of premature ventricular contractions within two hours of exposure was noted for each increase of 10 µg/m3 in PM2.5.
Fan He et al,Journal of the American Heart Association,DOI: 10.1161/JAHA.122.026370