Question: I’m 65 andbeen at it hard for umteen years and competing in my age division with success until recently. Why the demise? I have a problem with the ticker — arrhythmia. My cardiologist calls it ‘athlete’s heart.’ With this arrhythmia there was no real symptom other than the workouts feel harder and the race results weren’t as usual. My condition and treatment are still being assessed, and I might be in for an ablation process to reconnect the heart’s circuitry. I thought this experience might be of interest to your other readers. — Rob D.
Dr. Richard Ellin Responds: The term “arrhythmia” is used to refer to any rhythm of the heart other than the regular, normal cadence initiated by the usual pacemaker of the heart, known as the sinoatrial (SA) node. There are many different types of arrhythmias, most of which are benign, but a few of which can be dangerous. The term “athlete’s heart” is not synonymous with “arrhythmia.” While certain abnormal heart rhythms may be more common in athlete’s hearts, there is no evidence that any of them are of the dangerous kind.
Regarding the issue of “athlete’s heart,” Professor Robert Fagard has summarized the research on this. Most studies indicate the following: According to a meta-analysis (summary of all relevant studies) of male cyclists (69 of them) and matched controls (65), heart rate was lower by 16 beats/min in the cyclists. Left ventricular (the main pumping chamber) internal diameter, wall thickness, and left ventricular mass were larger in the athletes. In addition, the athletes’ relative wall thickness exceeded that of the control subjects by 19%, indicating that cycling is not only associated with an increase of the internal diameter but also with a disproportionate thickening of the wall (mixed eccentric-concentric LVH).
While cycling is predominantly a dynamic activity (continuous movement), rather than a static activity (such as weight-lifting), this difference could be explained by the fact that cycling involves static activity of the upper part of the body and by the increase of blood pressure associated with intensive cycling. In an analysis of 947 elite athletes (not necessarily cyclists), Dr. Antonio Pelliccia and colleagues observed that absolute wall thickness was independently associated with body surface area, age, and male gender, but also with certain sports such as rowing and cycling. They did not, however, analyze relative wall thickness as the dependent variable in multiple regression analysis.
The various studies on cyclists agree that left ventricular mass is larger than in matched non-athletes due to a larger left ventricular internal diameter and wall thickness. A large amount of training may lead to a disproportionate increase in wall thickness, which could be related to the static component involved in cycling.
Having said all that, there is also evidence that the enlargement of left ventricular structure is not associated with any decrease in left ventricular systolic function (pumping ability), and is associated with a small beneficial improvement in left ventricular diastolic function (relaxation of the ventricle to allow blood to flow into it). There are no data to suggest that the structural changes cited above are detrimental.
For anyone questioning whether or not they have a healthy heart, only an exam (and perhaps some testing) by their doctor can determine that.
Richard Ellin, MD, FACP, is a board-certified specialist in Internal Medicine who practices in Alpharetta, Georgia. He received his medical degree and completed residency at Emory University, and has been in practice with Kaiser Permanente for 26 years. He is also an avid cyclist.
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