Atrial fibrillation in athletes: implicit literature-based connections suggest that overtraining and subsequent inflammation may be a contributory mechanism

Med Hypotheses. 2006;66(6):1085-92. doi: 10.1016/j.mehy.2006.01.006. Epub 2006 Feb 28.


Research on atrial fibrillation (AF), a common heart arrhythmia in the elderly, over many decades has resulted in a literature of more than 16,000 articles indexed in Medline. An exploratory Medline search was conducted in which the subheadings for epidemiology and etiology of AF were combined to form a small subset of the initial records. Further computer-assisted selection led to a few articles that reported an unexpectedly high prevalence of AF in groups of otherwise healthy middle-aged endurance runners and other athletes. Why athletes should be unusually susceptible to AF is mysterious and puzzling. Because relatively few articles are about both AF and endurance exercise, a computer was used first to create a list of important terms that these two separate literatures had in common. Several inflammation-related terms, including C-reactive protein (CRP) and interleukin-6, were on that list. Further searching and literature analysis revealed that excessive endurance exercise or overtraining can lead to chronic systemic inflammation and, separately, that there is a solid association between CRP and AF and that anti-inflammatory agents have been reported to lower CRP and ameliorate AF. No articles were found that brought together all three concepts - AF, inflammation, and exercise. The following hypothesis is plausible, readily testable, and apparently novel: Older athletes diagnosed with AF but otherwise healthy who have engaged in rigorous aerobic endurance exercise for more than a decade will have CRP levels that are higher than those of a similar population of athletes without AF. Corroboration of this hypothesis would then justify a prospective clinical trial of anti-inflammation therapy. It is of particular interest to extend recent studies of inflammation in AF to athletes; athletic behavior that can induce inflammation may contribute to understanding the origins of AF.

Publication types

  • Meta-Analysis
  • Research Support, N.I.H., Extramural

MeSH terms

  • Atrial Fibrillation / epidemiology*
  • Causality
  • Comorbidity
  • Cumulative Trauma Disorders / epidemiology*
  • Exercise Movement Techniques / statistics & numerical data*
  • Exercise*
  • Humans
  • Incidence
  • Inflammation / epidemiology*
  • Periodicals as Topic / statistics & numerical data
  • Sports / statistics & numerical data*