In 490 BC, Phidippides, a young Greek messenger, ran 26.2 miles from Marathon to Athens delivering the news of the Greek victory over the Persians, and then he collapsed and died. This is probably the first recorded incident of sudden death of an athlete.

The possibility that young, well-trained athletes at the high school, college, or professional level could die suddenly seems incomprehensible. It is a dramatic and tragic event that devastates families and the community. Sports, per se, are not a cause of enhanced mortality, but they can trigger sudden death in athletes with heart or blood vessel abnormalities by predisposing them to life-threatening heart irregularities.

Sudden death most commonly occurs in football or basketball, accounting for two-thirds of sudden death of athletes in the US. In the rest of the world, soccer is the sport most commonly associated with sudden death. Sudden death occurs in 1 to 2 in 200,000 athletes annually and predominately strikes male athletes.

Some well-known athletes who have been victims of sudden death include marathon runner Jim Fixx (1984), Olympic volleyball star Flo Hyman (1986), NBA basketball star Hank Gathers (1990), Olympic figure skater Sergei Grinkov (1995), all pro NFL player Korey Stringer with the Minnesota Vikings (2001), and Darryl Kile, all-star pitcher for the St. Louis Cardinals (2002). In my hometown, Jed Bedford, captain of the Columbus State University basketball team and NCAA Division II leader in 2002 for 3-point shots, collapsed during practice and died one hour later on December 14, 2003.

The second most common cause of sudden death in athletes is abnormal coronary arteries (the blood vessels that supply oxygen to the heart muscle). Often, coronary arteries originate from an abnormal location or have an acute twisting angle that slows the blood flow. Other cardiac abnormalities that can cause sudden death are heart valve abnormalities, electrical conduction abnormalities of the heart, and rupture of the aorta (the large blood vessel that carries the blood from the heart to the body).

Another cause of sudden death among athletes is Marfan syndrome (Fig. 2). Marfan syndrome affects approximately 1 in 20,000 of the general population. People who have this medical condition are usually tall, slender, and loose-jointed. It is a hereditary disorder of the connective tissue, which is the basic substance that holds blood vessels, heart valves, and other structures together. Olympic volleyball star Flo Hyman had Marfan syndrome. On June 8, 2004, Florida State basketball player Ronalda Pierce died from an aorta rupture that was a result of this syndrome.

Most sudden death in athletes over the age of 30 is due to a heart attack, or blockage of the coronary arteries. The otherwise normal arteries are occluded with lipid plaque. Athletes who are older than 30 are at increased risk for heart attack if they smoke, have high blood pressure, diabetes, elevated abnormal lipids, or a strong family history of heart disease. Darryl Kile, pitcher for the St. Louis Cardinals, died suddenly at age 33. (His father died of a heart attack at age 44).

Noncardiac causes
A blow to the chest in the area of the heart, called commotio cordis, or cardiac concussion is the most common cause of sudden death in athletes who have no heart abnormality. This condition often occurs in children or adolescents with a nonpenetrating-and usually innocent appearing-blow to the middle of the chest, such as when a baseball, hockey puck, lacrosse ball, softball, or karate blow strikes the athlete's chest.

Screening
High school and college athletes usually have a physical examination by a physician before participating in organized sports. Athletes with a family history of sudden death, Marfan syndrome, or heart disease at a young age, a history of exercise-induced syncope (fainting), a loud heart murmur, or previous heart surgery require further evaluation by a cardiologist. The preparticipation sports history and physical examination is often not sensitive enough to pick up rare heart conditions. Screening probably does identify 3% to 15% of athletes at risk.

Signs and symptoms
Chest pain, syncope (fainting), dizziness, palpitations (sensation of a rapid or irregular heart beat), fatigue, and excessive or prolonged shortness of breath can be innocent sensations that can accompany intense exercise. Nevertheless, they should be evaluated by a physician because they could be a sign of a heart or lung disorder.

Although sudden death in athletes is devastating, it is very rare and the benefits of exercise for all ages are recognized by improved lipid levels, glucose (sugar) tolerance, enhanced self-assurance, and improved overall quality of life. There are many things we can do to help prevent exertional related illness or death. Exercise in the morning or evening during warm months, drink plenty of fluids, and avoid alcohol and caffeinated beverages. Be sure to inform your physician if there is a family history of heart disease, stroke, or sudden death. If you are over 30 years of age and are starting an exercise program, seek advice from your primary care physician. Don't smoke, avoid anabolic steroids and stimulants, and report any chest pain, fainting, dizziness, unusually rapid heartbeat, fatigue, and excessive or prolonged shortness of breath to your health care provider.

David McMicken, MD, FACEP
Columbus, Georgia

References:

1. Maron BJ. Sudden Death in Young Athletes. N Engl J Med. 2003:1064-1075.
2. Maron BJ, Chaitman BE, Ackerman MJ, et al. Recommendations for Physical Activity and Recreational Sports Participation for Young Patients with Genetic Cardiovascular Disease. Circulation. 2004;109:2807-2816.