• CARDIAC PROCEDURES AND THERAPY

Prevention of atrial fibrillation (AF) would positively impact global health by decreasing stroke, heart failure and cardiovascular mortality, as well as by improving quality of life for many patients. Older age, hypertension, and obesity are associated with an increased risk of AF in patients without underlying valvular heart disease, heart failure or coronary disease. However, the effects of chronic exercise on AF risk are controversial. Studies in men suggest a lower risk of AF in older men engaging in moderate physical activity, but a higher risk of future AF in younger men engaged in frequent, long-term, intense levels of activity.1 ,2 Few studies have examined the relationship between exercise and AF risk in women.

In the Swedish Mammography Cohort of over 36 thousand middle-aged women, with a median age of 60 years, about 8% were diagnosed with new AF during 12 years of followup (see page 1627). Increasing levels of leisure time physical activity at study entry were associated with a lower risk of AF with a relative risk of 0.85 (95% CI 0.75 to 0.95) for ≥4 hours/week versus <1 hour/week. The effect of walking or bicycling for transport was similar with a relative risk of 0.81 (95% CI 0.72 to 0.99) for ≥40 minutes/day versus almost never (figure 1). In this study, a moderate amount of physical activity was adequate to reduce AF risk with no evidence …