Reviewed by Alex SmithMay 23 2022
As per the study presented recently at Heart Failure 2022, a scientific congress of the European Society of Cardiology (ESC), fatal arrhythmias are more usual on days with highly polluted air.
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This research was conducted on patients who have an implantable cardioverter-defibrillator (ICD), thereby allowing the authors to monitor the happening of arrhythmias and delivery of life-saving therapy.
Our study suggests that people at high risk of ventricular arrhythmias, such as those with an ICD, should check daily pollution levels. When particular matter (PM) 2.5 and PM 10 concentrations are high (above 35 μg/m3 and 50 μg/m3, respectively), it would be sensible to stay indoors as much as possible and wear an N95 mask outside, particularly in areas of heavy traffic. An air purifier can be used at home.
Dr Alessia Zanni, Study Author, Maggiore Hospital
According to the reports gathered by the World Health Organization, outdoor air pollution kills an estimated 4.2 million people annually. Around one in five cardiovascular disease deaths are due to dirty air. This was ranked the fourth-highest risk factor for mortality following a poor diet, tobacco use, and blood pressure.
This study analyzed the relationship between air pollution and ventricular arrhythmias in Piacenza, Northern Italy. The European Environment Agency ranked the city 307 worst out of 323 cities for annual mean PM2.5 concentrations in 2019 and 2020, with a figure of 20.8 μg/m3.
We had observed that emergency room visits for arrhythmias in patients with ICDs tended to cluster on days with particularly high air pollution. We therefore decided to compare the concentration of air pollutants on days when patients had an arrhythmia versus pollution levels on days without an arrhythmia.
Dr Alessia Zanni, Study Author, Maggiore Hospital
The study consisted of around 146 patients who received an ICD between January 2013 and December 2017. Among them, 93 received an ICD due to heart failure following a heart attack while 53 had an inflammatory or genetic heart condition.
Just over half (79 patients) had never undergone a ventricular arrhythmia, and 67 patients had had a ventricular arrhythmia earlier.
Data obtained on ventricular arrhythmias (ventricular fibrillation and ventricular tachycardia) were gathered remotely from the ICD until the study was completed at the end of 2017. Also, the scientists recorded the therapy that was delivered by the device.
This involved anti-tachycardia pacing for ventricular tachycardia (fast heartbeat), which helps deliver electrical impulses to the heart muscle. This can further restore a normal rhythm and heart rate. The second therapy was known to be an electric shock to reset the heartbeat at the time of ventricular fibrillation.
Daily levels of PM10, PM2.5, nitrogen dioxide (NO2), ozone (O3), and carbon monoxide (CO) were gathered from Regional Environmental Protection Agency (ARPA) monitoring stations.
Based on their home address, patients were assigned exposures. The scientists examined the link between pollutant concentrations and ventricular arrhythmias.
A sum of 440 ventricular arrhythmias were recorded at the time of the study period, of which 118 were treated with a shock and 322 were treated with anti-tachycardia pacing. The scientists discovered a considerable link between PM2.5 levels and ventricular arrhythmias treated with shocks. This equals a 1.5% greater risk for each 1 μg/m3 rise in PM2.5.
Also, they discovered that when PM2.5 concentrations were increased by 1 μg/m3 for a whole week, on the average levels, there was a 2.4% greater probability of ventricular arrhythmias irrespective of the temperature. There was a 2.1% increased risk of arrhythmias when PM10 was 1 μg/m3 above average for a week.
Particulate matter may cause acute inflammation of the heart muscle which could act as a trigger for cardiac arrhythmias. As these toxic particles are emitted from power plants, industries and cars, green projects are needed to protect health, on top of the actions individuals can take to protect themselves.
Dr Alessia Zanni, Study Author, Maggiore Hospital
Zanni added, “These data confirm that environmental pollution is not only a climate emergency but also a public health problem. The study suggests that the survival of patients with heart disease is affected not only by pharmacological therapies and advances in cardiology but also by the air that they breathe.”
“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,” continued Zanni.
This study received no particular grant from any funding agency in the public, commercial, or not-for-profit sectors.