AF can occur in otherwise healthy people with no known heart disease, and is most often detected during stress or exercise. AF also shows up in people who've had coronary heart disease, heart attack, heart failure, heart valve disease, an inflamed heart muscle or lining, or who recently have had heart surgery. People with atherosclerosis (arteries lined with fatty deposits) and angina (chest pain) sometimes have it, and it also has been linked to congenital heart defects.
AF sometimes appears in people with chronic lung disease, pulmonary blood clots, emphysema and asthma. Other factors that affect risk for AF are thyroid disorders, diabetes, high blood pressure, excessive alcohol consumption and cigarette smoking-some of which are modifiable.