Clinical InvestigationHigh-intensity endurance training is associated with left atrial fibrosis
Section snippets
Study population
We recruited 20 endurance Masters athletes >35 years old who have participated in at least 10 years of competitive endurance sports and actively train for ≥10 hours weekly.14 Endurance activities included those that were highly dynamic with low static component: running, cycling, ski mountaineering, and Nordic skiing (Table1). For the athlete cohort, recruitment was done through word of mouth at training clubs and at competitions. Efforts were focused specifically on top finishers in local
Results
Overall, the 2 cohorts were very closely matched with few comorbidities. Athletes had significantly lower BSA. The athletes also weighed significantly less and had a lower body-mass index (BMI) (Table I). Participants in the athlete cohort reported training regularly for an average of 28.98 ± 8.65 years and a mean of 15.53 ± 6.9 hours each week (Table II). The majority of that time was spent training in endurance activities (12.48 ± 5.84 h/wk). Most athletes train in more than one sport but of
Discussion
To our knowledge, this is the first study which demonstrated an increased level of atrial fibrosis in Masters endurance athletes as compared to healthy non-athletic controls. The cardiovascular benefits of daily exercise are well recognized. However, endurance athletes appear to develop atrial arrhythmias at higher rates compared to the general population, with an estimated 5–10 fold increase the prevalence of AF amongst endurance athletes.9., 10., 11., 12.,17 While there are speculations
Conclusion
Our study describes and characterizes fibrotic changes within the LA of highly trained endurance athletes. We have shown that in otherwise healthy participants, with no history of arrhythmia, endurance training is associated with a higher level of atrial fibrosis as compared to age and gender matched controls. Atrial fibrosis seen in this population could be an early indicator for those athletes at highest risk for arrhythmia development. Future longitudinal studies should focus on
Acknowledgements
We wish to thank the additional members of the Comprehensive Arrhythmia Research & Management Center (CARMA) at the University of Utah for their support and expertise in performing and analyzing each research scan.
Funding
Comprehensive Arrhythmia Research & Management Center (CARMA) at the University of Utah Cardiology Department, Salt Lake City, Utah.
Declaration of competing interest
There are no pertinent relationships with industry.
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