After surgery, a patient with sleep apnea discovered she also had atrial fibrillation, a serious irregular heart rhythm, reports Everyday Health.

Harvey-Collens is not alone in having sleep apnea and atrial fibrillation. The incidence of sleep apnea among people with atrial fibrillation varies from 32 to 49 percent, according to a 2012 report in the journal Current Cardiology Reviews. These figures may even be higher because physicians do not routinely screen patients for sleep apnea, says William Abraham, MD, director of the division of cardiovascular medicine at Ohio State University’s Wexner Medical Center.