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Why
Do Athletes Experience Sudden Deaths?
March
14, 2000
By Barry Franklin
The occurrence of sudden death among seemingly fit amateur and
professional athletes is always shocking, and it always raises
immediate questions about the underlying causes of death and the
thoroughness of the pre-participation screening of competitive
athletes.
Recently, these concerns were echoed by the tragic deaths of two metro
Detroit athletes.
A Plymouth-Salem student, Mark Bolger, 16, died after he collapsed
in the locker room during halftime of a high school basketball
game. The next day, Searborn Hardy, a 16-year-old student at Detroit's
Sankore Marine Immersion High School and Academy, was fatally
stricken at the Wolverine Recreation Center during tryouts for
a youth basketball league. Since 1997, three other students in
Michigan have died during training or athletic competition.
In recent years, there has been a series of sudden deaths among
top athletes. In 1995, figure skater Sergei Grinkov, a 28-year-old
two-time Olympic gold medalist, slumped to the ice and died of
a heart attack while training. The Grinkov incident came after
the untimely deaths of basketball stars Hank Gathers, Reggie Lewis
and Len Bias and Olympic volleyball player Flo Hyman.
Well publicized at the time was the 1988 death of NBA star Pete
Maravich during a pickup game of basketball. A postmortem on Maravich,
who was just 40, revealed that his heart had no left coronary
artery.
How often do these deaths occur?
Sudden death in athletes is a rare occurrence. There are approximately
100 cases annually in the United States.
The prevalence of such deaths among high school players is one
in 200,000. Among athletes over the age of 35, available estimates
suggest that the frequency of exercise-related sudden death, principally
because of coronary artery disease, is considerably higher: one
in 15,000 joggers, for instance, and one in 50,000 marathon runners.
How could this happen?
One explanation for the perplexing occurrence of exercise-related
deaths in conditioned athletes lies in the erroneous assumption
that people who are fit are also healthy.
Nearly all athletes who die during physical exertion have some
form of heart disease. The combination of exercise and a diseased
heart seems to be the major cause of sudden death in athletes.
To a large extent, the deaths are linked to age. Partial or total
blockage of the coronary arteries is the most frequent autopsy
finding in athletes over the age of 35 who die suddenly. By contrast,
inherited structural abnormalities of the heart are the major
cause of sudden death during training or competition among younger
athletes.
One of the most common abnormalities leading to sudden death among
young athletes is known as hypertrophic cardiomyopathy, found
in one-third to one-half of all cases. This inherited condition
involves an enlargement of the cells of the heart muscle and can
cause electrical conduction disturbances and potentially fatal
heart rhythms.
The second-leading cause of sudden death involves structural defects
of the coronary arteries. This refers to abnormalities in the
blood vessels that deliver blood to the heart. Often, these defects
result in death during vigorous activities because of the vessels'
inability to meet the increasing demands on the heart.
A third cause is myocarditis, a disease process often triggered
by a viral infection. This was the prime suspect in the death
of 27-year-old Lewis of the NBA's Boston Celtics. He collapsed
in 1993 while playing basketball.
Athletes with a family history of Marfan's syndrome are generally
advised to refrain from strenuous activities or sports involving
body contact. This is a genetic connective tissue disorder that
is characterized by abnormally long bones, excessive joint flexibility
and blood vessel abnormalities. The condition is more prevalent
in sports in which the athletes have an increased height and arm
span, such as basketball.
Other less common causes of sudden death include profound electrolyte
(sodium/potassium) disturbances, heat stroke, powerful blunt contact
to the chest wall, cocaine or anabolic steroid abuse and sickle
cell trait.
Exercise can trigger the event
The high heart rate and blood pressure responses that accompany
vigorous training or competition may deprive the heart muscle
of sufficient oxygen. This can cause lethal heart rhythms in athletes
who have cholesterol-clogged coronary arteries or structural cardiac
abnormalities.
Greater-than-usual blood flows also may dislodge pieces of built-up
cholesterol from blood vessel walls. These pieces may precipitate
blood clots in a coronary vessel and starve a portion of the heart
muscle of oxygen and nutrients so that it dies. The result: a
heart attack.
Do we need more extensive screening programs?
Some 200,000 symptom-free athletes would have to be screened to
identify 10 who are at increased risk for a fatal cardiac event
that may kill only one person.
Medical evaluations on these athletes might include a resting electrocardiogram
(ECG), 24-hour ECG monitoring, exercise stress testing, an echocardiogram
(a machine using reflected ultrasonic waves to show the structures and
functioning of the heart) or combinations of these.
Several studies suggest that routine, intensive screening of athletes
for potentially lethal cardiovascular conditions is impractical
because of the small diagnostic yield, high cost, potential for
false-positive tests and the low incidence of deaths.
Can we identify the athlete at risk?
Medical experts agree that it is difficult to identify athletes
who may be fatally stricken during physical activity. One important
clue, however, has emerged.
Athletes who die suddenly often experience warning symptoms in
the weeks or months before the fatal event. These include chest
or stomach pain, dizziness, rapid or irregular heart rates, increased
fatigue and fainting. Studies suggest that up to 80 percent of
athletes who die suddenly had experienced warning symptoms.
Several years ago, doctors in Vermont developed a simple questionnaire
that can be used as part of the pre-participation evaluation to
screen athletes at risk. This survey, along with the physical
examination, is designed to identify the most common abnormalities
associated with sudden death.
Which screening guidelines are appropriate?
In 1996, an expert panel appointed by the American Heart Association
issued the nation's first set of standardized recommendations
for screening young athletes for potentially fatal heart disease.
The recommendations include:
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Make
pre-participation cardiovascular screening, a physical examination
and a complete personal and family history mandatory. |
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Repeat
the screening every two years on high school and college athletes. |
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Listen
to the athletes' hearts while they are standing and lying
down to identify significant murmurs and other structural
abnormalities. |
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Include
blood pressure measurements in each physical examination.
The athlete should be seated during these. |
The panel noted that these recommendations can be applied to older
athletes as well as professional athletes.
BARRY FRANKLIN, PhD, is director of
the cardiac rehabilitation program at William Beaumont Hospital
and president of the American College of Sports Medicine. Write
to him at: Barry Franklin, c/o Detroit Free Press; P.O. Box 828;
Detroit, MI 48231.
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