Air pollution can trigger cardiac arrhythmias in healthy young people

Air pollution can trigger cardiac arrhythmias in healthy young people

Inhaling particulate matter (i.e., tiny particles suspended in the air) can trigger irregular heart rhythms (arrhythmias) in healthy teenagers, according to a new study published today in the Journal of the American Heart Association, an open-access, peer-reviewed journal of the American Heart Association.

While the negative cardiovascular effects of air pollution on adults have been established previously, this study is the first to evaluate the effects of air pollution on teenagers in the general population.

Although 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 in adolescents. Because cardiovascular disease in childhood and adolescence can be traced back into adulthood and can influence later risk of serious cardiovascular disease, identifying modifiable risk factors for cardiac arrhythmias that can lead to sudden cardiac death in adolescents should be of great public interest.”

Fan He, Ph.D., lead author of the study and lecturer in public health sciences at Penn State College of Medicine in Hershey, Pennsylvania

The study examined the effects of inhaling particulate matter on the heart rhythm of adolescents. Particulate matter (PM2.5) is smaller than 2.5 micrometers and can easily be inhaled deep into the lungs and even enter the bloodstream. Particles smaller than 2.5 microns are usually associated with fuel combustion, such as: B. Particles from car exhaust or forest fires. Once inhaled, the pollutants irritate the lungs and blood vessels around the heart, and previous research has shown that pollutants increase the disease process in the arteries over time.

Researchers analyzed the effects of particulate matter air pollution on two types of irregular heart rhythms, characterized by premature contraction of the heart muscle, often called “heart stops.” In premature atrial contractions (PAC), the heartbeat originates in the atria (upper chambers of the heart). This usually doesn't cause symptoms or damage, but frequent, premature atrial contractions have been linked to an increased risk of atrial fibrillation - a severe form of arrhythmia in which the upper chambers tremble instead of beating effectively, increasing the risk of blood clots. Premature ventricular contractions (PVC) occur when the heartbeat originates in one of the ventricles (lower chambers of the heart). These also increase the risk of a later heart attack, stroke, heart failure or sudden cardiac death.

If premature labor does not cause symptoms, it is not treated. However, if they occur frequently and cause you to often feel a skipped heartbeat, rapid heartbeat, or palpitations, treatment with medications, implantable devices, or procedures may be advised.

Researchers analyzed health data from 322 adolescents (mean age 17 years; 56% male; 79% non-Hispanic white teens) living in central Pennsylvania who participated in a follow-up assessment of the Penn State Child Cohort Study. This study, conducted between 2002 and 2006, initially recruited children ages 6 to 12. The data analyzed in this study verified the results of the follow-up assessment almost 7.5 years later (2010-2013). This group of children was free of major cardiovascular disease and was considered at low risk for cardiac arrhythmias. In the follow-up study, researchers simultaneously measured exposure to particulate matter in each teen's breath (using a device called a nephelometer) for 24 hours and ECG recordings of each teen's heart rhythms via a small wearable device called a Holter monitor.

The average PM2.5 concentration measured in the study was about 17 micrograms of particulate matter per cubic meter of air (µg/m3) per day, which is well below the health-based air quality standard of 35 µg/m3 set by the US Environmental Protection Agency (EPA).

The study found:

• 79 % der Teilnehmer hatten während des 24-stündigen Studienzeitraums mindestens einen unregelmäßigen Herzrhythmus. Von dieser Gruppe hatten 40 % nur vorzeitige atriale Kontraktionen, 12 % nur vorzeitige ventrikuläre Kontraktionen und 48 % hatten beides.

• Für jeden Anstieg von 10 µg/m3 bei PM2,5 wurde eine 5%ige Zunahme der Anzahl vorzeitiger ventrikulärer Kontraktionen innerhalb von zwei Stunden nach der Exposition festgestellt.
• Es wurde kein Zusammenhang zwischen der Partikelkonzentration und der Anzahl vorzeitiger Vorhofkontraktionen gefunden.

"It is alarming that we observed such a significant impact of air pollution on cardiac arrhythmias, even though air quality remained within health-based standards set by the EPA. This may indicate that youth living in highly polluted areas such as inner cities are at even greater risk," he said.

The results were consistent with data previously obtained in adults using similar methods by these researchers and others, although the increase in premature ventricular contractions was even higher in adults. Reducing the risk of irregular heart rhythms in teenagers may reduce their risk of developing heart disease as adults, according to the study authors.

"Our study found that air pollution increases the risk of cardiovascular disease and sudden cardiac death, even in healthy adolescents," he said. “On days with high levels of particulate matter, particularly during early morning rush hours, protective measures such as wearing masks and avoiding vigorous physical activity may be warranted.”

The most effective way to reduce everyone's exposure to air pollution is to support stricter air quality regulations at the national level, said American Heart Association volunteer expert Robert D. Brook, MD, FAHA, professor of medicine at Wayne State University in Detroit. Brook is co-author of several American Heart Association scientific statements on air pollution.

“PM2.5 levels have fallen dramatically since the 1970s and 1980s due to regulations that have undoubtedly been linked to improved health outcomes and life expectancy,” Brook said. “We outlined strategies and activities or behavior changes that can reduce pollution exposure, such as: E.g. portable air purifiers, face masks, respirators and exercise during off-peak hours. However, there are no studies showing that these measures can actually prevent adverse clinical health effects such as heart attacks.”

Air pollution is widely considered a major contributor to cardiovascular disease and death, according to a 2020 American Heart Association policy statement citing a global study. In 2017, exposure to particulate air pollution was linked to more than 7 million premature deaths and the loss of 147 million years of healthy life worldwide. The association recommends further development of evidence-based policy approaches, continued investment in research, and increased innovation and transformational partnerships to reduce the cardiovascular burden of air pollutants in the United States

“Clearly the most interesting and significant aspect of this study is that the results were found in healthy young adolescents,” Brook said. "The study supports the concern that even healthy young people are not immune to adverse cardiovascular reactions to PM2.5 and at exposure levels within the 24-hour national air quality standards set by the EPA. It is plausible that the results help explain the possible reason for the timing of the onset of arrhythmias and even sudden death in some susceptible young people People."

Dr. He and his colleagues are currently studying the effects of air pollution on other markers of the heart's electrical activity.

This study was limited because it was unable to analyze the effects of air pollution on different subtypes of premature ventricular contractions, which could help cardiologists better understand how air pollution affects heart function. The results of this study in adolescents may not be generalizable to younger children.

Source:

American Heart Association

Reference:

Er, F., et al. (2022) Acute effects of particulate matter air pollution on cardiac arrhythmias in a population-based sample of adolescents: The Penn State Child Cohort. Journal of the American Heart Association. doi.org/10.1161/JAHA.122.026370.

.