Exercise Training and Atrial Fibrillation: Further Evidence for the Importance of Lifestyle Change.

Abstract

Atrial fibrillation (AF) is the most common clinical arrhythmia with a global burden that has increased progressively, contributing to rising hospitalizations and substantial healthcare demands.1–3 Although aging is an important contributor to the rising AF prevalence, key mechanistic promoters of AF include modifiable risk factors such as obesity, hypertension, diabetes mellitus, and obstructive sleep apnea. Article see p 466 Exercise training and physical activity improve the management of hypertension and diabetes mellitus,4 assist in weight management,5 and improve cardiac structure and function.6 Surprisingly, despite these favorable modifications of arrhythmogenic risk factors, greater physical activity only modestly reduces incident AF rates.7,8 At the extreme end of the exercise spectrum, endurance athletes, who engage in the greatest volume of exercise training, encounter a risk of AF that rises significantly. Cohort studies provide estimates of AF risk in the endurance athlete population that range from a 2-9 to 7-fold10 elevation in incident AF risk. Until recently, the AF and exercise story has stopped here: that physically active individuals experience a small reduction in risk, but doing too much increases arrhythmia risk considerably, consistent with a classic J-shaped phenomenon. Perhaps, in part because of these findings and a misguided fear of promoting arrhythmias, there is a scarcity of data regarding the effects of exercise training in patients with nonpermanent AF. In the current issue of Circulation , Malmo et al11 provide the results of their randomized, controlled trial, in which they compared a popular form of high-intensity exercise, aerobic interval training, with a control group who were not prescribed exercise. The authors randomly assigned 51 AF patients referred for catheter ablation to exercise or no exercise over 12 weeks, and recorded AF burden from implantable loop recorders as the primary study outcome. …