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Sudden Cardiac Death in Athletes

By Robert S. McKelvie, MD, PhD, Professor of Medicine; Secondary Prevention and Heart Failure Programs, Western University; St. Joseph's Health Care

An estimated 1 to 3 per 100,000 apparently healthy young athletes develop an abrupt-onset heart rhythm abnormality and die suddenly during exercise. Males are affected 10 times more often than females. Basketball and football players in the United States and soccer players in Europe may be at highest risk.


Generally, the causes of sudden death during exercise are very different in young athletes than in older athletes. However, in all athletes, asthma, heatstroke, and the use performance-enhancing or recreational drugs may cause death due to sudden abnormal heart rhythms.

Young athletes

In young athletes, the most common cause of sudden cardiac death is

Other heart disorders, such as long QT syndrome or Brugada syndrome that cause abnormal heart rhythms, and aortic aneurysms may also cause sudden death in young athletes.

Less commonly, undetected heart enlargement (dilated cardiomyopathy) may be present in a young person who has no symptoms, and the person may die suddenly during or after vigorous exercise.

Abnormalities of the coronary arteries, especially when one of the arteries takes an abnormal path through, rather than on top of, the heart muscle, may also cause sudden death in athletes when the compression cuts off blood flow to the heart during exercise.

Rarely, young, thin athletes may also have sudden heart rhythm disturbances if they experience a blow to the area directly over the heart (commotio cordis) even when they have no heart disorder. The blow often involves a fast-moving projectile such as a baseball, hockey puck, or lacrosse ball or impact with another player.

Older athletes

In older athletes, the most common cause is


Some athletes have warning signs such as fainting or shortness of breath. Often, however, athletes do not recognize or report these symptoms, and the first sign is that the person suddenly stops breathing and collapses.


  • Screening before exercise participation


People are commonly screened by their doctor before starting an exercise program. Doctors screen people who have medical disorders and also those who do not think they have any medical disorders. People without known medical disorders should be checked because some serious disorders do not cause problems until people exercise. People are reevaluated every 2 years (if high school age) or every 4 years (if college age or older).

Doctors always ask people questions and do a physical examination, but they do testing only depending on the person's age and symptoms. Questions focus on three areas:

  • Symptoms such as chest pain or discomfort, fainting or near-fainting, fatigue, and difficulty breathing, particularly when these symptoms occur during vigorous exercise

  • Family history, particularly any history of family members who fainted or died during exercise, or who died suddenly before about age 50

  • Use of drugs

The physical examination focuses on listening to the heart with a stethoscope for heart murmurs that indicate a possible heart disorder and measuring blood pressure with the person lying down and again while the person is standing.

For younger people, doctors typically do not do any tests unless something abnormal is identified in the person's history or is found during the physical examination. Routine use of electrocardiography (ECG) screening of young athletes is not considered practical in the United States. However, if findings suggest a heart problem, doctors typically do ECG, echocardiography, or both.

For people over age 35, doctors may also do ECG and exercise stress testing before approving vigorous exercise.

If a heart disorder is found, the person may need to stop participating in competitive sports and undergo further testing. Some people with severe heart disease, such as hypertrophic cardiomyopathy, should not participate in competitive sports. However, most people with heart disease may participate in noncompetitive sports. Increased activity is directly related to better health outcomes such as a decrease in "bad" cholesterol levels (low-density lipoproteins), prevention of high blood pressure, and reduction of body fat. Regular exercise is routinely included in care plans for people with most forms of heart disease (cardiac rehabilitation).

Did You Know...

  • Even people with heart disease can usually participate in some physical activity.


  • Resuscitation

If people stop breathing and collapse, immediate treatment is with

Resuscitation is continued in the emergency department. If the person survives, doctors treat the condition that caused the abnormal rhythm. Sometimes doctors place an implantable cardioverter-defibrillator, which continually monitors the person's heart rhythm and delivers a shock to return the rhythm to normal if needed.

Automated External Defibrillator: Jump-Starting the Heart

An automated external defibrillator (AED) is a device that can detect and correct a specific type of abnormal heart rhythm called ventricular fibrillation. Ventricular fibrillation causes cardiac arrest.

If cardiac arrest occurs, an AED, if available, should be used immediately. An AED is used before calling for help and before attempting cardiopulmonary resuscitation (CPR) because an AED is more likely to save lives. If the AED detects ventricular fibrillation, it provides an electrical shock (defibrillation) that can restore normal heart rhythm and start the heart beating again. Emergency medical care should be obtained even if the heart has started beating again. If a person remains in cardiac arrest after an AED is used, CPR should be done.

AEDs are easy to use. The American Red Cross and other organizations provide training sessions on the use of AEDs. Most training sessions take only a few hours. Different AEDs have somewhat different instructions for use. The instructions that are written on the AED being used should be carefully followed.

AEDs are available in many public gathering places, such as stadiums and concert halls. People who are told by their doctor that they are likely to develop ventricular fibrillation but who do not have an implanted defibrillator may want to purchase an AED for home use by family members.

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