The Health Gazette

 

Sudden Death in Athletes

Karl Hempel, M.D.

 

It is always a shock when a presumably healthy athlete dies suddenly.  After the sad and untimely death of a local longtime Tallahassee runner, I was asked to write an article about sudden death in athletes for The Fleet Foot. 

 

Sudden deaths are usually caused by underlying heart problems.  Deaths that are caused by heart problems are divided into individuals under the age of 30 and those over the age of 30.  Cardiac deaths that occur in athletes under age 30 are usually caused by congenital problems such as:

 

  1. Hypertrophic cardiomyopathy, a hereditary condition characterized by an enlarged heart that is very susceptible to fatal cardiac arrhythmias.
  2. An abnormally formed coronary artery.
  3. Rupture of the aorta, the main artery leading from the heart, usually occurring in people with a condition called Marfan's syndrome.
  4. Myocarditis, a viral infection of the heart muscle.
  5. Prolonged QT syndrome, a problem with the heart conduction system making the heart susceptible to fatal cardiac arrhythmias.
  6. Congenital valvular heart conditions. 
  7. Arrhythmogenic right ventricular dysplasia, a condition that causes fibrosis of the heart muscle and a susceptibility to fatal cardiac arrhythmias.

 

 

It is very difficult to diagnose many of these conditions with a routine physical exam with the exception of valvular heart problems.  All athletes in the Florida school system are required to have sports physicals before they can participate in school sponsored athletic programs.  These exams are tailored to detect medical problems that are associated with a risk of sudden cardiac death. An EKG can usually diagnose prolonged QT syndrome and sometimes suggest if the patient has other heart problems leading to further more definitive diagnostic studies.

 

Sudden deaths in athletes older than age 30 are usually caused by coronary artery disease.  Coronary artery disease refers to the buildup of plaque in the arteries that provide blood to the heart muscle.  The leading cause of death in the United States is obstruction of one of these vessels resulting in a heart attack. If the buildup of plaque causes over a 90% blockage of the coronary artery, a stress test is helpful in making the diagnosis.  We know now that many heart attacks are caused by the rupture of a small plaque in the coronary artery resulting in a blood clot and ultimately a heart attack.  These small lesions are not usually detected by a stress test.  A plain EKG will not show buildup of plaque in the coronary arteries but can show if the patient has had a previous heart attack or has an abnormal heart rhythm.

 

 

Frequently, the first sign of a coronary artery disease is sudden death.  Many times people will experience chest, arm, throat, shoulder or back pain as an early sign of heart disease.  Dizziness, palpitations or unusual fatigue can also be early warning symptoms of heart disease.  It is very important to have these symptoms checked out before resuming exercise.  It is also prudent to ask your physician if you should have a stress test before starting an exercise program.  This is certainly not always necessary, but for males over 40 and females over 50 it is probably worthwhile, particularly if you have risk factors for heart disease. Risk factors are:

 

Diabetes

Family history of heart attacks before age 60.

Inactivity

Smoking

High cholesterol

High blood pressure

 

Exercise reduces the risk of developing coronary artery disease but it does not make one immune to a heart attack.  Other less common causes of sudden death in people over 30 are valvular heart problems, viral myocarditis and hypertrophic cardiomyopathy.  Heat strokes also are responsible for some cases of sudden death in athletes.

 

Fortunately, sudden death in athletes is a very rare occurrence.  There have been several studies that estimate the risk of sudden death during jogging.  One study by PD Thompson estimated the risk to be one death per 396,000 hours of jogging.  Another study looked at deaths that occurred in the Marine Corps Marathon over a 19 year period.  There were four deaths and three of them had coronary artery disease on autopsy.  None of these four marathoners had known coronary artery disease before their death.  The incidence of death in marathoners is estimated to be one death per 215,000 hours of racing.  Another study calculates the incidence of sudden death in noncompetitive exercise as one death per 375,000 hours of exercise.

 

To put things in perspective, let us look at the number of deaths caused by inactivity.  The general consensus is that at least 200,000 people die in the United States every year because they do not exercise.  The Center for Disease Control has a web site (http://www.cdc.gov/nccdphp/factsheets/death_causes2000.htm) that lists the actual causes of death in the United States in 1990 as compared to 2000.  Inactivity and poor diet caused 300,000 deaths in 1990 and 400,000 deaths in 2000.  Smoking caused 400,000 deaths in 1990 and 435,000 deaths in 2000.  Using the rate of increase, inactivity and poor diet is now the leading cause of death in the United States in 2004. 

 

It is impossible to prevent all sudden cardiac deaths in athletes.  Nevertheless, there are some general guidelines that are advisable to follow:

 

  1. Never ignore pain or unusual sensations that occur in the chest, arm, shoulder, jaw, throat or back especially if these occur with exercise.  Patients will frequently describe these unusual sensations as pain, indigestion, aching or pressure. 
  2. Do not use any stimulants when exercising or particularly when racing.  Ephedrine has caused a number of deaths but fortunately has been taken off the market.  Many diet pills have a stimulant in them.  Stimulants cause the heart to be more susceptible to cardiac arrhythmias.
  3. It is better not to race or even run hard when you have a bad cold.  Fever, chills and muscle aches are indicative of a bad cold.  Coxsackie virus is responsible for many cases of myocarditis that can precipitate cardiac arrhythmias and sudden death.
  4. Do not drink alcohol and then race or run hard.  Alcohol is toxic to the heart muscle and can increase the probability of arrhythmias.
  5. It is important to realize that even though exercise is an extremely healthy habit to develop, it does not make you invincible.  Listen to your body.  If you feel particularly bad it is probably better not to race or run hard.

 

In conclusion, I believe that exercise is the most important thing that we can do for our health.  It increases our longevity and improves the overall quality of life.  Sudden cardiac death in athletes certainly can occur but is extremely rare.  Conversely, sudden cardiac death in people who don't exercise is extremely common. In fact, it is now the leading cause of death in the United States.

 

References

 

Mokdad, AH, Marks, JS, et al. Actual Causes of Death in the United States, 2000. JAMA 2004, 291:1238-1245.

 

Hosey, RG, Armsey, TD. Sudden cardiac death. Clinics in Sports Medicine Jan 2003; Vol 22, Number 1

 

Corrado, D, Basso, C, Schiavon, M, et al. Screening for hypertrophic cardiomyopathy in young athletes. N Engl J Med 1998; 339:364.

 

Powell, KE, Blair, SN. The public health burdens of sedentary living habits: Theoretical but realistic estimates. Med Sci Sports Exerc 1994; 26:851.

 

Maron, BJ, Poliac, LC, Roberts, WO. Risk of sudden cardiac death associated with marathon running. J Am Coll Cardiol 1996; 28:428.

 

Thompson, PD, Funk, EJ, Carleton, RA, et al. Incidence of death during jogging in Rhode Island from 1975 through 1980. JAMA 1982; 247:2535.

 

http://www.cdc.gov/nccdphp/factsheets/death_causes2000.htm

 


The information provided above is offered as a community service about health-care issues and is not a substitute for individual consultation. Advice on individual problems should be obtained from your personal physician. This information is based on research by the author and represents his interpretation of the literature.

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