On days of heavy pollution, cardiac arrhythmias are more frequent, especially in people with implantable cardioverter defibrillators.
- According to the World Health Organization, more than 4 million people die each year from air pollution.
- The study took place in the city of Piacenza in Italy, which is very poorly classified by the European Environment Agency because of poor air quality.
- Fine particles can cause acute inflammation of the heart muscle, which could explain the occurrence of arrhythmias.
Air pollution threatens our heart health? In any case, it weakens people with cardiovascular pathologies. According to one study made public at the congress of the European Society of Cardiology, people with an implantable automatic defibrillator (ICD), which can correct anomalies in the electrical activity of the heart, are more vulnerable on pollution days.
The effects of different types of pollutants analyzed
“We had observed that emergency room visits for arrhythmia in patients with ICDs tended to cluster on days when air pollution was particularly high.“, notes Dr. Alessia Zanni, of the Maggiore Hospital in Bologna. “We therefore decided to compare the concentration of air pollutants on the days when the patients had an arrhythmia with the pollution levels on the days without arrhythmia.“
The team of Italian scientists recruited 146 patients. Among them, 93 received an ICD due to heart failure after a heart attack while 53 had genetic or inflammatory heart disease. Slightly more than half (79 patients) had never had a ventricular arrhythmia and 67 patients had already had one. It was either tachycardia, when the heart beats too fast, or fibrillation, when the ventricles of the heart fail to contract and blood flow is interrupted. In the absence of defibrillation, the person loses consciousness and risks dying quickly. The ICD makes it possible to correct these cardiac arrhythmias. At the same time, it gives information on situations in which the heart rhythm has been disturbed. It is this data that the researchers analyzed in the patients. They also contacted the monitoring stations of the Regional Environmental Protection Agency to obtain daily levels of PM10, PM2.5, carbon monoxide (CO), nitrogen dioxide (NO2) and ozone (O3). Thanks to the addresses of the patients, they were able to estimate their level of exposure to these various pollutants present in the air. Next, the researchers analyzed the association between the concentrations of pollutants and the occurrence of ventricular arrhythmias.
Increased risks, whatever the type of particles
Over the entire duration of the study, 440 ventricular arrhythmias were recorded. Some required a shock, performed in the hospital, to regulate the heart rate. The researchers found a significant association between PM2.5 levels and ventricular arrhythmias corresponding to a 1.5% increased risk for each 1 μg/m3 increase in PM2.5. They also found that when PM2.5 concentrations were elevated by 1 μg/m3 for an entire week, compared to average levels, the likelihood of ventricular arrhythmia was 2.4% higher. When PM10 was 1 μg/m3 above average for a week, the risk of arrhythmia increased by 2.1%.
“Our study suggests that people at high risk for ventricular arrhythmias, especially those with an ICD, should check pollution levels daily.”, says the author of the study. “When PM2.5 and PM10 fine particle concentrations are high, above 35 μg/m3 and 50 μg/m3, respectively, it would be helpful to stay indoors as much as possible and wear an N95 mask outside. outdoors, especially in heavy traffic areasShe also recommends using an air purifier at home.
