Many of us have seen media reports about an athlete who collapsed and died during an athletic event. We have also heard about the promising athlete who was disqualified from competition because of a cardiac condition which predisposed to sudden cardiac death. The sudden cardiac death of a healthy young athlete is a traumatic event. The death of an athlete runs contrary to many of our societal beliefs about illness and death. Young athletes are seen as the picture of health, vitality, and youth. Exercise is associated with good health and is not thought of as dangerous or deadly. Because of this, it is essential to understand the myths and facts surrounding sudden cardiac death in athletes. Recently, there has been a great deal of attention directed at understanding and preventing sudden cardiac death. These measures have improved our understanding and led to the successful implementation of preventative measures; however, there continues to be room for improvement.
There is a perception that the occurrence of sudden cardiac death in athletes is increasing. This is actually untrue, and the increasing national awareness, in all likelihood, may be attributed to greater media attention and sports participation. We currently live in a world where global news, with a growing emphasis on sports, is available around the clock. Studies have shown that sudden death in NCAA athletes occurs in 1.2-2.3 of every 100,000 athlete participation years. In comparison, automobile fatalities in the same age range are 2500 times more likely to occur. Sudden cardiac death in athletes is more common in males (6 times more common than females) and in African-Americans (5 times more common than in white athletes). Basketball and swimming are the two sports with the highest occurrence.
Sudden cardiac death in athletes is caused by multiple cardiac conditions.
Sudden cardiac death in athletes is caused by multiple cardiac conditions. Hypertrophic cardiomyopathy is the most common cause accounting for 36-44% of all cases. Hypertrophic cardiomyopathy is a disease of the heart muscle resulting in abnormal thickening of heart walls and a predisposition to abnormal heart rhythms and sudden death. This condition often presents in the teenage years and young adulthood. Exercise in patients with hypertrophic cardiomyopathy can cause abnormal heart rhythms and sudden death. Hypertrophic cardiomyopathy is often caused by the inheritance of an abnormal gene from a parent. This makes the identification of athletes with a strong family history an essential component of screening. Other less common causes of sudden cardiac death in athletes include: congenital coronary artery abnormalities, viral infections of the heart muscle (myocarditis), arrhythmogenic right ventricular cardiomyopathy (ARVC), and congenital predispositions to heart rhythm abnormalities.
Prevention of sudden cardiac death in athletes consists of identifying those with predisposing diseases and excluding them from athletic participation as well as providing appropriate emergency services when an event occurs. The latter consists of CPR training of observers and ensuring that automated external defibrillators (AEDs) are available at athletic events. AEDs can be effective but must be rapidly available and used immediately after an event. Although AEDs are available at many athletic events, there is still room for improvement as many locations and events do not have them.
Screening of athletes for diseases which cause cardiac sudden death is also very important. It is imperative that screening identify all athletes at risk so they can receive appropriate care and be excluded from athletic participation. However, it is also important that screening not inadvertently label healthy individuals as being at risk, unnecessarily excluding them from exercise and possibly leading to adverse health consequences related to a sedentary lifestyle. In the US, screening consists of a medical history and physical examination. The medical history identifies symptoms indicating a possible predisposing cardiac disease. The medical history also consists of a detailed family medical history which singles out those more likely to have an inherited predisposing condition. The physical examination evaluates for the typical cardiac findings of underlying diseases. If abnormal results are present on the history and/or physical examination, the athlete should be excluded from athletic participation and referred to a cardiologist. Evaluation by the cardiologist will include a medical history and physical examination and may also include an electrocardiogram (recording of the electrical activity of the heart) and echocardiogram (ultrasound of the heart). Based on the findings, the cardiologist will decide whether athletic participation is safe.
Great strides have been made in our understanding and prevention of sudden cardiac death in athletes; however, the continued occurrence of events indicates there is room for improvement. This is an active area of research, and with a better understanding of the underlying diseases, providers will be better able to identify and treat those at risk.
Screening for conditions which predispose to sudden cardiac death can occur in the context of well child check-ups and athletic participation evaluations.
- Sudden cardiac death in young athletes is rare.
- The vast majority of children and young people can exercise safely and without fear.
- Screening for conditions which predispose to sudden cardiac death can occur in the context of well child check-ups and athletic participation evaluations.
- Young people wishing to participate in athletics should be evaluated and screened by their primary care provider.
- A community’s goal should be to have automated external defibrillators (AEDs) at all sporting events. This goal provides an opportunity for community advocacy.
Michael Jay Campbell, MD, is an associate professor in pediatrics (cardiology) in the Duke Department of Pediatrics in Durham, NC.
Harmon KG, Asif IM, Klossner D, Frezner JA. Incidence of sudden cardiac death in National Collegiate Athletic Association athletes. Circulation. 2011 Apr 19. 123(15):1594-600.
Maron BJ, Haas TJ, Murphy CJ, Ahluwalia A, Rutten-Ramos S. Incidence and causes of sudden death in US college athletes. J Am Coll Cardiology. 2014 Apr 29. 63(16):1636-43.
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