Pollution and health: poor air quality would increase cardiac arrhythmias

An Italian study, presented at the Heart Failure 2022 congress of the European Society of Cardiology (ESC), which was recently held in Madrid (Spain), shows that more people would visit the emergency room on days with poor air quality.

What is arrhythmia?

Arrhythmia – or heart rhythm disorder – corresponds to a variation in heart rate for no apparent reason. According to the Foundation for Medical Research, these variations are explained by the simple exaggeration of the normal rhythm. The heart therefore tends to beat too slowly (bradycardia), too fast (tachycardia) or irregularly (arrhythmia).

Many forms of arrhythmia cause no health problems, although they sometimes cause bothersome symptoms, such as dizziness or chest pain.

But it also happens that they have repercussions on the blood supply and therefore require medical treatment. This is the case, for example, with the implantation of the implantable automatic defibrillator (ICD), a device that helps the heart to function properly, thanks to the transmission of electrical impulses.

Identify air quality-related arrhythmia with the DAI

The study conducted by doctors in northern Italy showed the importance of ICDs in medical research. “It’s a way to monitor the onset of abnormal heartbeats, in hopes of identifying factors that may be triggering them.”observes Dr. Franco Folino of the Department of Cardiac, Thoracic and Vascular Sciences at the University of Padua, interviewed by the site MedicalNewsToday. One of these factors is air quality.

“These devices, as well as many pacemakers, are terrific devices not only for the treatment of arrhythmias but also for their ability to monitor heart rhythm around the clock. They are therefore an ideal tool for comparing arrhythmia profiles with air quality monitoring station data”, observes Doctor Franco Folino.

The study was conducted in Piacenza. This city, located about 60 km from Milan, was classified, in 2021, by the European Environment Agency for European Cities, among the agglomerations with the highest levels of air pollution.

According to the World Health Organization (WHO), an average annual concentration of very fine particles (PM 2.5) of 10 μg/m3 or less constitutes good air quality. That of Piacenza showed a rate of 20.8 μg/m3, placing its air quality in the category “poor”.

“We observed that emergency room arrivals for arrhythmia in patients with ICDs tended to cluster on days when air pollution was particularly high. We therefore decided to compare the concentration of air pollutants on days when patients had an arrhythmia versus pollution levels on days without arrhythmia”, explains Dr. Alessia Zanni, from the cardiology department of the Piacenza hospital and co-author of the study.

The researchers thus followed the activity of the DAI in 146 people who had received an implant between January 2013 and December 2017. In this group, 67 people had already suffered from a ventricular arrhythmia, the 79 others, not.

The Regional Environment Agency, for its part, provided the researchers with daily air quality figures. During the study, the researchers recorded 440 ventricular arrhythmias. The ICDs of the affected patients delivered a shock in 118 cases.

Ultimately, the results revealed that each 1 μg/m3 increase in PM 2.5 levels corresponded to a 1.5% increased risk of arrhythmia requiring shock.

When PM 2.5 concentrations remained elevated by 1 μg/m3 for one week, ventricular arrhythmias were 2.4% more frequent.

Pollution, a risk factor like any other

Several studies have already established the dangers of pollution for the body. This new publication reinforces the idea that pollution should be considered a risk factor for cardiovascular health, just like smoking, alcoholism or even hypercholesterolemia.

“While continuing to address these risk factors, we must act to prevent people in general, but especially those at high cardiovascular risk, from being exposed to high levels of air pollution”emphasizes Dr. Folino.

For Dr. Zanni, simple precautions should be taken when the concentrations of very fine particles (PM 2.5) and fine particles (PM 10) are high (above 35 g/m3 and 50 μg/m3 respectively):

• Stay indoors as much as possible;
• Wear an N95 mask outdoors, especially in high traffic areas.

“This study confirms that pollution is not only a climate emergency but also a public health problem. This battle can be won by an alliance between scientific societies and politicians to protect not only the environment but also the health of the human population”warns Alessia Zanni.