The dramatic heart-related deaths of young athletes naturally grab headlines. But the reality is that sudden death in athletes is actually quite rare. Still, it presents difficult challenges for doctors, trainers, coaches and especially parents of young athletes. The principal challenges are how best to screen athletes for heart disease before a heart attack or sudden death occurs and what to advise when abnormalities are detected.
In November 2004, experts from the fields of cardiology and sports medicine convened for what is called the Bethesda Conference to address the issues. The experts involved in the conference focused on competitive athletes and their hearts, but they realized that their recommendations would be applied beyond their primary intentions. Since more and more people are engaging in recreational exercise, doctors and their patients need evidence and expert opinions to help guide the types and intensity of physical activity.
The authors of the report recognized that many important questions remained unanswered and that individual circumstances will always influence what ultimately is decided for competitive and recreational athletes.
The recommendations from the Bethesda Conference are still pertinent now.
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Screening for Problems
The American Heart Association recommends screening of athletes before competition with a questionnaire and a physical examination by a health care professional.
The questionnaire includes these questions:
Do you have one or more of the following?
- A heart murmur
- High blood pressure
- Chest pain with exertion
- Excessive fatigue
- Marked or unexplained shortness of breath with exertion
- Episodes of losing consciousness or feeling faint, especially if this occurred during exertion or exercise
- A family history of heart disease under the age of 50
- A family member, especially a first-degree relative (sibling, parent or child), who experienced unexplained sudden death
During the physical examination, the health care professional looks for the following:
- General appearance consistent with Marfan's syndrome — Clues that a person may have Marfan's include being tall and thin; having long arms, legs and fingers; and having a highly arched palate. People with Marfan's are at high risk for heart and blood vessel abnormalities.
- Blood pressure greater than 140/90 millimeters of mercury (mmHg)
- A heart murmur that is worrisome — An example would be a murmur that gets louder when the person moves from a lying to a standing position.
- Weak pulses in the legs compared with the arms — This can indicate a narrowing in the aorta, called coarctation of the aorta.
A "yes" response to any of the above questions does not immediately exclude a person from competition. Nor does a suspicious finding during a physical exam. These are called screening criteria because they are meant to be sensitive — that is, designed to have a low threshold for alerting the health care professional of a possible abnormality. They are not definitive indicators of health problems.
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Evaluating the Results
A positive answer or physical finding to any of these criteria would prompt further testing, starting with a routine electrocardiogram (EKG). A normal resting EKG does not exclude a heart problem that might be significant.
The next test is often an echocardiogram, using sound waves that provide a moving picture of the heart. The echocardiogram shows the size of the chambers within the heart and the thickness of the walls of each chamber. It also shows the structure and function of the heart valves and tells the doctor the strength of the heart's pumping action. In most instances, a normal EKG and completely normal echocardiogram are reassuring enough to let an athlete compete.
For those athletes who have chest pain or shortness of breath, an exercise stress test under doctor supervision also might be ordered.
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The Athletic Heart
An EKG or echocardiogram that shows findings outside of the "normal" range does not necessarily mean the athlete has heart disease. Up to 40% of highly trained athletes with normal hearts can show changes on an electrocardiogram that would be read as abnormalities. And 15% to 20% of echocardiograms will show thickening of the wall of the left ventricle or enlargement of the inside chamber. These findings are all consistent with an athletic heart — one that is actually much stronger than average.
But a thickened wall of the left ventricle might instead represent a disorder called hypertrophic cardiomyopathy and the enlarged cavity could be related to a dilated cardiomyopathy. Additional cardiac testing or genetic testing may be needed to differentiate the normal athletic heart from the one that could be at risk with extreme exertion. These tests would determine whether the athlete can safely compete.
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High Blood Pressure
Not surprisingly, high blood pressure is the commonest cardiovascular disorder seen in competitive athletes. High blood pressure readings above 140/90 would not immediately disqualify an athlete from competing. Even if the heart muscle showed thickening caused by the high blood pressure, the athlete still might be able to compete as long as the blood pressure was controlled — either by lifestyle changes or with medications. (Remember that all medications must be registered before any competition.)
If blood pressure is not controlled or is actually causing ongoing damage to the eyes, heart or kidneys, then competitive athletics must be put on hold until blood pressure and organ function show consistent improvement.
While competition is on hold, exercise does not have to stop. In fact, regular aerobic exercise, with or without light resistance training, lowers high blood pressure readings. Thirty minutes per day of exercise at 50% of maximal oxygen uptake or higher can lower blood pressure immediately after exercise with an effect that can persist for the next 24 hours.
However, heavy resistance training, such as strenuous weight lifting, is out because it sometimes can spike blood pressure and place excessive stress on the heart and blood vessels.
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Screening Recreational Athletes
Although no formal recommendation has been made to use the same screening criteria for non-competitive exercisers, the questionnaire and physical exam advised by the American Heart Association for competitive athletes is a good starting point for men under age 30 and women under age 35.
When a person who wants to begin strenuous exercise approaches age 40, screening also should include an assessment of risk factors for coronary artery disease. A person with risk factors such as positive family history, smoking, high LDL cholesterol, low HDL cholesterol, high blood pressure, high blood sugars or obesity should get clearance from his or her doctor first. Although most people don't require routine testing to begin exercise, symptoms such as chest pressure, marked shortness of breath or extreme fatigue do require diagnostic evaluation. They should not be accepted as just being out of shape.
Increase your exercise intensity level and duration gradually if you have not been physically active. Sudden bursts of heavy or intense exertion put a previously sedentary person at greater risk of heart attack or sudden death than someone who has reached a higher fitness level.
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Howard LeWine, M.D., is chief editor of Internet publishing, Harvard Health Publications. He is a clinical instructor of medicine at Harvard Medical School and Brigham and Women's Hospital. Dr. LeWine has been a primary care internist and teacher of internal medicine since 1978.