Air pollution increases risk of potentially deadly irregular heartbeat

By Mark Waghorn via SWNS

Air pollution increases the risk of developing a potentially deadly irregular heartbeat, according to new research.

On days when levels are high the life-threatening episodes, known as arrhythmias, are more common.

The finding is based on patients in Piacenza, Northern Italy, who had been fitted with battery-powered chest devices called ICDs (implantable cardioverter defibrillators).

Lead author Dr. Alessia Zanni, previously at Piacenza Hospital, said: "Our study suggests people at high risk of ventricular arrhythmias, such as those with an ICD, should check daily pollution levels.

"When particulate 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."

The toxic microscopic particles are emitted by traffic and industry and measured in micrograms per cubic meter.

Nearly one in five cardiovascular disease deaths are due to dirty air. It was ranked the fourth highest risk factor for death after high blood pressure, smoking and poor diet.

The European Environment Agency graded Piacenza 307 worst out of 323 cities for annual average PM2.5 concentrations in 2019 and 2020, with a figure of 20.8 μg/m3.4

Dr. Zanni, now at Maggiore Hospital, Bologna, said: "We had observed 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."

Her team recruited 146 consecutive patients who received an ICD between January 2013 and December 2017.

Of those, 93 had heart failure after a heart attack. The others had a genetic or inflammatory heart condition.

Just over half (79) had never experienced a ventricular arrhythmia, while the remaining 67 had.

Data on incidents were collected remotely from the ICD until study completion at the end of 2017. The researchers also recorded the therapy delivered by the device.

This included the delivery of electrical impulses to correct a fast heartbeat and restore a normal rate and rhythm fast heartbeat, or an electric shock that resets it.

Daily levels of PM10, PM2.5, carbon monoxide (CO), nitrogen dioxide (NO2) and ozone (O3) were obtained from Regional Environmental Protection Agency (ARPA) monitoring stations.

Patients were assigned exposures based on their home addresses. The researchers analyzed the link between concentrations and the occurrence of arrhythmias.

A total of 440 were recorded during the study period, of which 322 were treated with electrical impulses and the other 118 with a shock.

The researchers found a significant association between PM2.5 levels and arrhythmias treated with shocks, corresponding to a 1.5% increased risk for each 1 μg/m3 rise 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, there was a 2.4% higher likelihood of arrhythmias regardless of the temperature.

When PM10 was 1 μg/m3 above average for a week there was a 2.1% raised risk of arrhythmias.

Dr. Zanni said: "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."

Earlier this week an international team reported that air pollution killed almost 6.7 million people across the world in 2019 alone.

The PM2.5s and PM10s get into the bloodstream and travel to the lungs, heart, brain and other major organs.

They have been linked to cardiovascular disease, cancer, COPD (chronic obstructive pulmonary disorder) and even Alzheimer's.

Dr. Zanni added: "These data confirm environmental pollution is not only a climate emergency but also a public health problem.

"The study suggests 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."

She made the presentation at a European Society of Cardiology meeting in Madrid.