By Paul Clerc,
Atrial fibrillation occurs when the electrical activity of the heart enters into an abnormal rhythm. In normal circumstances, the atrium (small chamber) of the heart beats once followed by a beat of the ventricle (large chamber) in a 1:1 fashion. During atrial fibrillation, the atrial pumping is uncoordinated and more rapid. This fibrillation leads to inconsistent transition from the atrium to the ventricle therefore the atrial rate is much higher than the ventricular rate (>1:1). The fibrillation also leads to a compromised pumping action and blood circulates through the body less effectively. An irregular heart rate due to atrial fibrillation has associated risks such as cognitive dysfunction, left ventricular dysfunction/congestive heart failure and quite commonly stroke 2. Identification and management of atrial fibrillation is therefore necessary to decrease the burden of this condition.
Nearly 1.5-2.0% of the general population is estimated to have atrial fibrillation with the prevalence significantly increasing with age 1,3. Observational studies have also found increased prevalence in athletes 4,5. One meta-analysis showed that athletes (ranging from professional to recreational exercising at least 2 times a week) were nearly 5 times as likely to develop atrial fibrillation compared to non-athletes 4. These studies generally show that cohorts with the greatest amount of exercise are more likely to develop atrial fibrillation 4. Increased prevalence is often seen in competitive running, cyclists, cross country skiers, and other endurance sports 4,5. Although the increased prevalence of atrial fibrillation suggests that more exercise could be detrimental to cardiac health, it is important to note that increased exercise still led to significantly less coronary artery disease 4.
The dual increase in prevalence with age and increased endurance activity is important to bear in mind when discussing Masters Athletes (over 35). This cohort may have an elevated risk of developing atrial fibrillation due to both age and activity. Symptoms of atrial fibrillation include shortness of breath, heart palpitations, fast heart rate, fatigue, and more (Heart and Stroke Foundation List of Symptoms). Importantly, a noticeable impact on performance may occur as the heart can no longer pump blood around the body as efficiently due to the loss of rhythmic contraction 2.
Managing atrial fibrillation in aging athletes is difficult as there are no current guidelines 5. The 36th Bethesda Conference on athletes with cardiovascular abnormalities states that athletes are able to compete as long as there is no structural defect and have an appropriate ventricular response to exercise 6. In consultation with their physician, athletes may be prescribed different drugs to manage atrial fibrillation and exercise. Beta blockers and Calcium Channel Blockers may be utilized to control rate while Flecainide, Disopyramide, and Amiodarone are three common drugs to prevent arrhythmias 5. Occasionally, it may be recommended that exercise be temporarily stopped as detraining has been linked to improved atrial fibrillation symptoms 5.
In addition to managing atrial fibrillation, stroke risk must be considered as individuals with atrial fibrillation have a 5 times greater stroke risk than those without 5. Athletes with a CHA2DS2 – VASC score ≥ 2 may need to be on anticoagulants. Anticoagulants then carry a risk of bleeding which becomes an added challenge to sports participation 5. CHA2DS2-VASc is a score measuring stroke risk for those with atrial fibrillation with one point given to each category that is present:
- Congestive Heart Failure,
- Age over 75 (x2),
- Prior Stroke (x2),
- Vascular disease,
- Age over 65,
- Sex (female =1).
Overall, atrial fibrillation is one of the more common heart conditions athletes will deal with, especially as they age. Checking pulse for a regular rhythm is one simple method to screen for atrial fibrillation. Individuals should be able to anticipate when the next beat occurs but an atrial fibrillation rhythm is more unpredictable. As well, athletes should be aware of signs/symptoms such as rapid thumping in the chest, a fast and irregular heart rate, dizziness and fainting. Athletes should also speak with their physician regarding any unexplained decreases in performance. Screening athletes for heart diseases including atrial fibrillation can help identify issues early to better manage both the condition and performance.
- January, C.T., Wann, L.S., Alpert, J.S., Calkins, H., Cigarroa, J.E., Cleveland, J.C., … Yancy, C.W. (2014) 2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation. Journal of American College of Cardiology, 64 (21), 1-76.
- Camm, A.J., Kirchhoff, P., Lip, G.Y.H., Schotten, U., Savelieva, I., Ernst, S., … Zupan, I. (2010) Guidelines for the management of atrial fibrillation. European Heart Journal, 33 (19), 2369 – 2429.
- Camm, A.J, Lip, G.Y.H., De Caterina, R., Savelivea, I., Atar, D., Hohnloser, S.H. … Kirchhoff, P. (2012) Guidelines for the management of atrial fibrillation (2012) European Heart Journal, 33 (21), 2719-2747.
- Abdulla, J., Nielsen, J.R. (2009) Is the risk of atrial fibrillation higher in athletes than in the general population? A systematic review and meta-analysis. Europace, 11, 1156-1159.
- Turagam, M.K., Flaker, G.C., Velagapudi, P., Vadali, S., Alpert, M.A. (2016) Atrial Fibrillation In Athletes: Pathophysiology, Clinical Presentation, Evaluation and Management) Journal of Atrial Fibrillation, 8 (4): 66-72.