Measuring oxidative stress may help doctors predict the risk of developing atrial fibrillation, the most common heart beat irregularity.

Emory researchers have identified a connection between oxidative stress and enlargement of the heart’s left atrium, which leads to atrial fibrillation.

People with high levels of the amino acid cystine in their blood at the start of the study were two times more likely to develop atrial fibrillation over the next three years, even after correction for traditional risk factors. Leakage from a heart valve also increased the risk.

“Our results suggest that increased oxidative stress promotes remodeling of the heart and enlargement of the left atrium, which can increase the likelihood of atrial fibrillation,” saysNima Ghasemzadeh, an Emory cardiology researcher. “Studies targeting oxidative stress markers may have a valuable effect in reducing atrial fibrillation risk.”