The Triathlete’s Heart

In my September column at EnduranceCorner, I shared the findings from a recent study of triathletes’ hearts. A team of radiologists in Germany used cardiac MRI to make measurements of the sizes of each of the heart’s chambers as well as the thickness of the heart muscle in a group of elite triathletes. Their findings show the adaptive changes in the heart that occur with chronic endurance training.

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  1. says


    Interesting post. I was diagnosed with paroxsymal a fib. last week (cut short my IM Canada last month as it kicked in 4 hr into bike and did not abate for 90 min.). I found an article by Jostein Grimsmo, MD “Prevalence of Atrial Fibrillation in Various Age Groups of Male Norwegian Cross Country Skiers”. What are your thoughts on aging athletes (I’m 52) and a. fib?

  2. says

    Dr. T,

    Good to hear from you. Sorry to hear that an arrhythmia cut short your race at IM Canada. A bunch of my triathlete friends were competing that day.

    I’ve read the abstract of the article you mention. The study also received some attention in the popular press.

    Atrial arrhythmias are increasingly prevalent with increasing age. The problem is almost non-existent in 20-year-olds and is very common in 80-year-olds. It’s not surprising, then, that it’s also more common with age in athletes.

    Endurance athletes, though, have the additional “problem” that the left atrium enlarges with endurance training. And even after that training stops, the left atrium size does not return to normal. It’s thought that this left atrial enlargement predisposes endurance athletes to atrial arrhythmias, including atrial fibrillation.

    The article about the skiiers is interesting because some athletes developed the arrhythmias long after their competitive career had ended.

    For you….if the arrhythmia truly is paroxysmal (occurs only sometimes), it is more likely that it could be cured with ablation–either by catheter-based therapies or surgically. Medication could be considered, but you’d need to have a discussion about the benefits/risks/side effects of the potential medications.

    If I were in your shoes (and I’m also a long-distance triathlete and similar age), I’d be thinking really hard about finding a way to control the problem.

    Email me if you’d like to talk more.

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