Association of physical activity and atrial fibrillation: A systematic review

Background: Physical activity has numerous positive health effects. There is some controversy, however, regarding the association of physical activity and atrial fibrillation. This systematic review aims to summarize the evidence regarding the association of physical activity at different levels and atrial fibrillation. Methods and Results: A structured search of databases was performed to identify literature published until December 2009. We included studies that aimed to investigate the association between physical activity and atrial fibrillation. Two researchers assessed publications according to inclusion criteria and methodological quality. The overall quality of evidence was rated according to the Grade system. Of 855 publications, 10 studies met the inclusion criteria. The majority of studies had considerable risks of uncontrolled bias and confounding and there was substantial heterogeneity regarding levels of physical activity and strength of associations. One methodologically rigorous study reported substantial risk reductions associated with moderate intensity physical activity, another indicated modest increases in risk with high levels of vigorous physical activity. Five methodologically less reliable studies reported up to six fold increases in risk due to regular sport practice. Conclusion: The overall quality of evidence indicating increases in risk of atrial fibrillation due to physical activity is low. Most reports of large increases in risk associated with physical activity appear to be overestimated substantially. In light of the importance of regular physical activity for the public health, contradictory recommendations concerning the participation in physical activity should be considered cautiously before more rigorous studies have investigated this issue.