Air pollution can lead to irregular heartbeat almost immediately

Exposure to air pollution can increase the risk of arrhythmia – an irregular heartbeat – within hours, a large study has found.

Arrhythmia takes a number of forms, including atrial flutter, which can lead to heart palpitations and feeling light-headed, and supraventricular tachycardia, when the heart feels like it is racing.

Both are caused by disordered electrical activity in the heart, which in the most severe cases can lead to heart failure, heart attacks and strokes.

In a study of 2,025 hospitals in 322 Chinese cities – where air pollution is well above the World Health Organisation’s guidelines for safe air quality – researchers found exposure to particulate matter, nitrogen dioxide, sulphur dioxide, carbon monoxide and ozone was associated with significantly higher odds of arrhythmia.

‘We found that acute exposure to ambient air pollution was associated with increased risk of symptomatic arrhythmia,’ said Dr Renjie Chen, from the School of Public Health at Fudan University, Shanghai. 

‘The risks occurred during the first several hours after exposure and could persist for 24 hours. The exposure–response relationships between six pollutants and four subtypes of arrhythmias were approximately linear without discernible thresholds of concentrations.’

Between 2015 and 2021, researchers assessed 190,155 patients admitted to hospital suffering acute onset of an irregular heartbeat, and followed up each case three or four times, measuring their heart rate during the same time and day of the week over the following month.

The results concluded that exposure to air pollution was associated with the onset of cardiac arrhythmia almost immediately. The risk is reduced after 24 hours.

Writing in the Canadian Medical Association Journal, the authors said: ‘We found the strongest associations of air pollution with atrial flutter and supraventricular tachycardia, followed by atrial fibrillation and premature beats.

‘Although the exact mechanisms are not yet fully understood, the association between air pollution and acute onset of arrhythmia that we observed is biologically plausible.’

The team noted the speed that exposure to pollution affected patients, and with it the need to protect people in areas of poor air quality.

‘Our study adds to evidence of adverse cardiovascular effects of air pollution,’ they wrote. ‘This highlights the importance of further reducing exposure to air pollution and of prompt protection of susceptible populations worldwide.’

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