Air pollution increases the odds of developing atrial fibrillation (AFib) onset within hours of exposure in patients with a history of cardiac disease, according to a study published June 11 in the Journal of the American College of Cardiology.

Additional Resources Full Study ACC AFib Clinical Toolkit ACC's Anticoagulation Initiative AnticogEvaluator Mobile App ArrhythmiaSAP CardioSmart for Your Patients: About AFib

The study looked at 176 patients with dual chamber implantable cardioverter defibrillators (ICDs) for an average of 1.9 years. A case-crossover analysis was used during the study when testing the association of AFib onset with air quality, including particulate matter less than 2.5 µm aerodynamic diameter (PM^2.5), black carbon, sulfate, particle number, nitrogen dioxide (NO^2), sulfur dioxide (SO^2), and ozone (O^3), in the 24 hours prior to an arrhythmic event.

Overall, 49 of the 176 patients experienced 328 episodes of AFib that lasted more than or equal to 30 seconds. Results showed a strong correlation for PM^2.5 during shorter exposure widows, while positive but non-significant associations were found 24 hours prior to AFib onset. Two hours before an event (p=0.004) the odds of AFib were increased by 26 percent (95 percent confidence interval [CI], 8 to 47 percent) for each 6.0 µg/m^3 increase in PM^2.5. Fine particulate matter was an acute trigger of AFib, the authors note.

The study was unique in its ability to capture all (including asymptomatic) atrial arrhythmias in a population at high risk for subclinical and clinical cardiac events. The authors suggest that given AFib's association with stroke and cardiovascular disease, it likely contributes to the adverse outcomes of air pollution seen in epidemiologic studies.

Keywords: Stroke, Nitrogen Dioxide, Particulate Matter, Epidemiologic Studies, Carbon, Defibrillators, Implantable, Ozone, Sulfur Dioxide

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