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The incidence and prevalence of atrial fibrillation in the U.S. has increased in the last several years and is predicted to continue to increase in future decades. It is estimated approximately 12-15 million people in the United States will have atrial fibrillation by 2050. The aging population plays a role in the increasing incidence with the risk of developing atrial fibrillation in people 40 years of age and older is approximately 25%. Another major risk factor of atrial fibrillation is obesity. Approximately 38% of the United States population is considered obese with a BMI of 30 or greater. Thus, it is no surprise the atrial fibrillation epidemic has followed the obesity epidemic.

Obesity contributes to the risk of hypertension and obstructive sleep apnea which are known risk factors of atrial fibrillation. Obesity is strongly associated with left atrial remodeling and dilatation. A complex interaction between neurohormonal factors, activation of inflammatory system resulting in increased levels of adipokines, and increased levels of growth factors results in enlargement and remodeling of the left atrium which is a predisposing factor of atrial fibrillation. Hypertension is present in 60% of obese patients which also contributes to left atrial dilatation. Dilation of the atria results in disorganized electrical activity and increased risk of atrial fibrillation.

Management of obese patients with atrial fibrillation is more complex than normal BMI patients with atrial fibrillation. Anticoagulation decisions are complicated as obese patients often require higher doses of warfarin due to decreased response. There is a lack of research data on the use of novel anticoagulants in obese patients. With rate control strategy, obese patients often have increased resting heart rates compared to normal BMI patients. Electrical direct current cardioversions are more difficult in obese patients and often require higher amount of Joules. Catheter atrial fibrillation ablations have increased risk of complications in obese patients.

Weight loss has benefit in atrial fibrillation patients not only due to decreasing risk of cardiac events but also decreasing symptom burden in obese atrial fibrillation patients. Weight loss in obese patients also decreases the risk of atrial fibrillation. With weight loss, there is cardiac remodeling with decreased left atrial size and volume resulting in decreased risk of recurrent atrial fibrillation. Studies show a decreased risk of atrial fibrillation with regular physical activity. The intensity of exercise also correlated with decreased risk of atrial fibrillation with a greater decrease in those walking faster or longer distances. Patients should be reassured the safety of engaging in moderate exercise and decreased risk of atrial fibrillation. Clinicians should routinely advise moderate exercise in atrial fibrillation patients.

Atrial fibrillation is a growing epidemic resulting in increased risk of morbidity and mortality. With an increase in prevalence, atrial fibrillation contributes to increasing cost of health care. Obesity contributes to an increased risk of atrial fibrillation. With continued increased incidence of obesity, clinicians can expect the atrial fibrillation epidemic continue to grow. Obese patients with atrial fibrillation are more difficult to treat, thus more studies are needed to treat obese patients with atrial fibrillation more safely and effectively.

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Obesity, exercise, obstructive sleep apnea, and modifiable atherosclerotic cardiovascular disease risk factors in atrial fibrillation by Miller, J. D., Aronis, K. N., Chrispin, J., Patil, K. D., Marine, J. E., Martin, S. S.,…Calkins, H.
The role of obesity in atrial fibrillation by Nalliah, C. J., Sanders, P., Kottkamp, H., &Kalman, J. M.