Atrial Fibrillation Symptoms

Risk Factors

Atrial fibrillation is the most common serious heart rhythm disorder, affecting 5% to 9% of individuals over the age of 65. Although experts are not certain about what causes atrial fibrillation, a variety of factors can be involved.

• Age. Studies show that the number of people who develop atrial fibrillation doubles with each decade after age 50; about 9% of people who reach the age of 80 will have atrial fibrillation. One reason is that changes in the atria—for example, buildup of scar tissue, protein, or starch deposits, and inflammation—tend to occur naturally with aging. In addition, these changes can result from diseases that are more common in older people, such as diabetes and coronary artery or heart valve disease.
• Gender. Men are 1.5 times more likely to develop atrial fibrillation than women are, although women who develop it have a greater risk for early death.
• Heart disease. There are several heart conditions that increase the likelihood for atrial fibrillation—especially heart valve disease, heart failure, and heart attack. Others include high blood pressure, endocarditis, and cardiomyopathy. Coronary artery disease and rheumatic heart disease also increase risk.
• Other conditions. Lung disease, blood clots that form in the lungs, emphysema, and asthma also seem to affect the heart in ways that can lead to atrial fibrillation. Diabetes and thyroid disease also affect risk.
• Lifestyle factors. Other important factors that increase the likelihood of developing atrial fibrillation include cigarette smoking, alcohol abuse, and use of stimulant drugs such as cocaine, amphetamines, and even caffeine.