Athletic Heart Syndrome is a non-pathological condition seen in sports medicine in which the athlete’s heart is enlarged and the resting heart rate is lower than normal.

It is common in athletes who routinely exercise more than five hours a week and occurs primarily with endurance (aerobic training) though it can sometimes arise in heavy weightlifters (anaerobic training).

This condition is generally considered benign but may be mistaken for a serious medical condition or, more alarmingly, may hide one.

AHS is, in fact, a normal, physiological adaptation of the body to the stress of exercise. Athletes with it do not have any physical symptoms, although they commonly display slow heartbeat (bradycardia) and enlarged/thick heart muscle (cardiomegaly and hypertrophy).

Bradycardia, at 40 to 60 beats per minute, is often picked up on physical exam. Cardiomegaly may or may not be present on physical assessment as it may or may not generate a special sign or murmur or extra sound. It is, however, easily diagnosed by cardiac tests.

Cause of AHS

During an intensive workout, more blood and oxygen are required to the peripheral tissues of the arms and legs in highly trained athletes. With that, a larger heart becomes needed to generate a higher blood output. With time, this also allows the heart to beat more slowly, as more blood is being pumped out with each beat.

AHS tests

• Electrocardiogram: typical findings in a resting position are bradycardia and/or electrical heart block and/or signs of a large heart.

• Echocardiography: it allows differentiation between AHS and some other similar but pathological conditions, mainly hypertrophic cardiomyopathy. It is important to make such a distinction as HCM is a serious cardiovascular disease. HCM is a genetic disorder found in one of 500 Americans and is a leading cause of sudden cardiac death in young athletes.

• Cardiac CT scan or cardiac MRI: considered if echo is inconclusive.

Cardiac screening in the young population

The above theme has led to much discussion. Should systematic screening be pursued in the young population, especially in athletes, to evaluate their cardiac status, rule out serious conditions like HCM, make sure any change in their heart rate and structure is solely from AHS, and assess their safety/readiness for exercise overall?

Reggie White and Marc-Vivien Foé are among the well-known athletes who succumbed to sudden cardiac arrest. Their deaths had a devastating impact on their teams and communities, and also on a national level.

Such a screening movement is advocating for a careful personal and family history collection, a comprehensive physical examination and an electrocardiogram. If the ECG were abnormal, additional cardiac testing would be considered.

While this approach became standard over the past decade in Europe and Australia, and encompasses nowadays screening all school-age children and young adults, it is not the case yet in North America, due to these main factors:

1, The prevalence of serious cardiac conditions in the healthy young population is quite low, and the cost of implementing such a nationwide screening procedure could be very taxing on the society.

2, Any abnormality found during screening would imply pursuing further tests and procedures that could be quite expensive, time-consuming, and mentally stressful to the young and his/her family.

Until the above dilemma is settled, a case-by-case approach is being considered in the USA, where the athlete’s preference, their team’s enrolment regulations and their healthcare provider’s suspicion for any worrisome personal or family cardiac disease, are being taken into account.

• Joe Yammine is a cardiologist at Bermuda Hospitals Board. He trained at the State University of New York, Brown University and Brigham and Women’s Hospital. He holds five American Board certifications. He was in academic practice between 2007 and 2014, when he joined BHB. During his career in the US, he was awarded multiple teaching and patients’ care recognition awards. The information herein is not intended as medical advice nor as a substitute for professional medical opinion. Always seek the advice of your physician. You should never delay seeking medical advice, disregard advice or discontinue treatment because of information in this article.