Exercise Restrictions and Suggestions for Hypertrophic Cardiomyopathy

young athletes playing soccer
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Hypertrophic cardiomyopathy (HCM) is one of the cardiac conditions associated with sudden death in young athletes

HCM is one of the more common genetic cardiac disorders, affecting one in every 500 people. In the United States, HCM accounts for 36% of the tragic sudden deaths that occur in young athletes. Furthermore, more than half of the sudden deaths that are caused by HCM occur in African Americans.

Anyone who has HCM needs to know about the risk of sudden death, and must be aware of the exercise recommendations experts agree should be followed by people who have this condition.

What Is Hypertrophic Cardiomyopathy?

HCM is a cardiac condition characterized by an abnormal thickening of the heart muscle, a condition called hypertrophy. The hypertrophy can cause several problems. It produces an excessive "stiffness" in the left ventricle of the heart. It can also cause a partial obstruction to blood flow in the left ventricle, producing a condition similar to aortic stenosis. HCM is also associated with abnormal function of the mitral valve.

These features of HCM can lead to diastolic dysfunction and diastolic heart failure, or to dilated cardiomyopathy and the more “typical” variety of heart failure. It can also cause mitral regurgitation, which itself can cause or worsen heart failure.

But the most dreaded consequence of HCM is that it can make the heart muscle prone to develop ventricular tachycardiaand ventricular fibrillation, arrhythmias that may produce sudden death. While these arrhythmias can occur at any time, they are by far most likely to occur during periods of vigorous exercise.

Unfortunately, sudden death may be the very first manifestation of HCM, especially in young athletes. Routine screening with an ECG, or better yet, an echocardiogram, would uncover the problem in most athletes before a life-threatening event — but given the millions of young athletes who participate in sports worldwide, such routine screening generally has been deemed cost prohibitive.

Nonetheless, any young athlete who has had a family member die suddenly, or who has a family history of HCM, needs to be screened for this condition. And if HCM is diagnosed, he or she should follow accepted exercise recommendations for young athletes with HCM.

How Is Exercise Related to Risk?

The risk of sudden death with HCM is higher during exercise than at rest. Furthermore, the risk caused by exercise appears to be related to the intensity of exercise and even the intensity of training.

In particular, highly dynamic sports including basketball, football and swimming, are associated with higher risk than less intensive sports, and that athletes in highly competitive programs (Division I as compared to Division 2 or Division 3 collegiate athletic programs) are at higher risk.

However, it is equally clear that the risk is not the same for everyone with HCM. Some people with HCM have sudden death at rest or during mild exertion, while others with HCM participate in extremely competitive, high-intensity sporting events for years without having life-threatening cardiac arrhythmias. 

Screening

Young people with HCM who wish to participate in competitive sports should be carefully screened. In addition to a physical examination, an echocardiogram should be performed to assess the degree of left ventricular thickening, the degree of left ventricular outflow obstruction, and to assess any mitral valve dysfunction. In addition, exercise stress testing should be performed to look for a normal blood pressure response (that is, an increase in blood pressure with increasing exercise levels), and to see whether there are any exercise-induced cardiac arrhythmias.

General Exercise Recommendations for Young Athletes With HCM

Given the variability in risk, and our limited ability to assign a specific risk level to a specific individual, recommendations on exercise recommendations for young athletes need to be individualized, and a fully transparent shared decision-making process should be employed.

General guidelines, published in 2019 by the European Association of Preventive Cardiology, recommend attempting to assign the young athlete with HCM either to a high-risk group or a lower-risk group. This assignment should be made after a medical history and physical examination, and after an echocardiogram and stress testing.

The high-risk group includes anyone who has had any of the following:

  • a history of cardiac arrest
  • symptoms suggesting a serious cardiac arrhythmia, especially syncope
  • cardiac dysfunction attributable to HCM
  • significant left ventricular outflow obstruction
  • abnormal blood pressure response to exercise

Those without of these features can be selectively allowed to participate in competitive sports, except sports where the occurrence of syncope could lead to serious injury or death. This decision should be made with full awareness that, despite being assigned to the lower-risk group, the risk of exercise with HCM is still higher than normal.

Finally, most experts agree that the risk associated with participation in activity of moderate intensity is generally not excessive in people with HCM in the lower-risk group, and, because physical activity is important to general health, it should not be discouraged. Such moderate activity includes things like  cycling, swimming laps, golf, doubles tennis, and skating.

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Article Sources

  1. Maron BJ, Udelson JE, Bonow RO, et al. Eligibility and Disqualification Recommendations for Competitive Athletes With Cardiovascular Abnormalities: Task Force 3: Hypertrophic Cardiomyopathy, Arrhythmogenic Right Ventricular Cardiomyopathy and Other Cardiomyopathies, and Myocarditis: A Scientific Statement From the American Heart Association and American College of Cardiology. J Am Coll Cardiol 2015; 66:2362. DOI:10.1016/j.jacc.2015.09.035

  2. Pelliccia A, Solberg EE, Papadakis M, et al. Recommendations for participation in competitive and leisure time sport in athletes with cardiomyopathies, myocarditis, and pericarditis: position statement of the Sport Cardiology Section of the European Association of Preventive Cardiology (EAPC). Eur Heart J 2019; 40:19. DOI:10.1093/eurheartj/ehy730

Additional Reading

  • Heidbüchel H, Corrado D, Biffi A, et al. Recommendations for participation in leisure-time physical activity and competitive sports of patients with arrhythmias and potentially arrhythmogenic conditions. Part II: ventricular arrhythmias, channelopathies and implantable defibrillators. Eur J Cardiovasc Prev Rehabil 2006; 13:676. DOI:10.1097/01.hjr.0000239465.26132.29