Air contaminants could be exacerbating the irregular heartbeats in healthy teenagers

Air pollution may be linked to the development of arrhythmia, an irregular heartbeat in normally healthy teenagers, according to recent research published by the Journal of the American Heart Association. This peer-reviewed journal is available for free access and offers immediate insights into current medical advancements.

Despite the undeniable adverse effects of air pollution on adults, this study is the first to investigate its impact on teenagers in a general population.

"While relatively rare, irregular heart rhythms can lead to sudden cardiac death in otherwise healthy adolescents and young adults. Our findings linking air pollution to irregular heart rhythms suggest that particulate matter may contribute to the risk of sudden cardiac death among youth,"

-Fan He, Ph.D., Public Health sciences instructor at Penn State College of Medicine in Hershey, Pennsylvania

The investigation assessed the influence of inhaling fine particulate matter on adolescent hearts' rhythms. PM2.5 - which measure less than 2.5 microns in size and can be easily swallowed into lungs - are typically generated during fuel combustion, such as automobile exhaust or wildfires; once inhaled, pollutants can cause irritation in the lungs and surrounding blood vessels - which could potentially lead to a heightened risk of developing cardiovascular disease.

Investigators analyzed the impact of polluted air on two types of irregular heart rhythms characterized by premature contraction in the atrial muscle, commonly referred to as a 'skipped beat.' In PAC, atrial contractions originate from within the top chambers of the heart - known as atria. Typically, these contractions do not pose any ill effects; however, if they occur too frequently or too soon, atrial fibrillation could result - an acutely aggravating form of arrhythmia characterized by irregularity in the beating of the upper chambers. As such it can increase the likelihood of blood clots and stroke. Premature ventricular contractions (PVCs) are a common malady affecting the heart. These occur when the arrhythmogenic originates from one of its ventricles – typically rendering an increased risk for cardiac events such as an acute myocardial infarction, stroke or even sudden cardiac death.

If premature contractions do not present any symptoms, they are typically ignored. However if these sensations regularly occur and cause a skipped heartbeat or an irregularly-paced pulse - progressively leading to a feeling of anxiousness or hurriedness - treatment with medications, implantable devices or procedures may be required.

Researchers combed through health data for 322 adolescents (average age at 17 years; 56% males; 79% non-Hispanic white teens) in central Pennsylvania who participated in a follow-up assessment within the Penn State Child Cohort study. This long-term study initially recruited children ages 6 to 12 during its duration from 2002 to 2006, and thus this recent research focused on analyzing their results from that revisitation approximately 7.5 years later (2010–2013). Being free of major cardiovascular conditions and considered at low risk for irregular heart rhythms, these groups provided researchers with an ideal sample pool. In the follow-up, scientists concurrently measured exposure to airborne particles by means of a nephelometer for an entire day and simultaneously recorded EKG tracings from each adolescent with a small battery-powered wearable device called a Holter monitor.

The study's average PM2.5 concentration measured was approximately 17 micrograms of particulate matter per cubic meter of air (µg/m3) per day, which is well below the health-based air quality standard established by the U.S. Environmental Protection Agency of 35 µg/m3.

What was found:

• The majority of participants (79%) showed at least one irregular rhythm during the 24-hour study period. Of that subset, 40% exhibited only premature atrial contractions and 12% had premature ventricular contractions; meanwhile 48% exhibited both forms of arrhythmia.
• A 5% escalation in the number of premature ventricular contractions within two hours of exposure was noted for every 10 µg/m3 increment in PM2.5 levels.
• No relationship was detected between the concentration of particulate matter and the frequency of premature atrial contractions.

"It is alarming that we were able to observe such a significant impact of air pollution on cardiac arrhythmias when the air quality remained well within the health-based standards established by the EPA. It may suggest that adolescents who live in highly polluted areas such as inner cities are at even higher risk,"

The data from this study was consonant with that previously obtained in adults using comparable methods by these researchers and others, though the magnitude of premature ventricular contractions increased markedly. Reducing the probability of irregular heartbeats in adolescents could help reduce their likelihood to develop heart disease as an adult according to its authors.

"Our study found that air pollution increases the risk of cardiovascular diseases and sudden cardiac death, even among healthy adolescents,...Protective measures, such as wearing masks and avoiding vigorous physical activities, may be warranted on days that particulate matter concentration is high, especially during early morning rush hours."

The most efficient approach to mitigating everyone's exposure to air pollution is enhanced national-level legislation, asserted Robert D. Brook, M.D., FAHA -volunteer expert with the American Heart Association and one of its top scientific authors on environmental matters. He has collaborated with colleagues on several authoritative reports regarding air quality issues.

The 2020 American Heart Association policy statement highlighting a global research study notably recognizes air pollution as an important factor in cardiovascular disease and fatalities. In 2017, exposure to particulate matter was estimated to be associated with more than 7 million premature deaths and the loss of 147 million healthy life-years globally. Consequently, policymakers should continue developing evidence-based policy approaches which provide protection against adverse health effects caused by ambient pollutants; invest in ongoing research efforts so that we may better understand this issue further; and collaborate with other stakeholders for transformative endeavors aimed at reducing the impact of these pollutants upon Americans' lives.

Source: ScienceDaily