Running Head: HYPERTROPHIC CARDIOMYOPATHY, THE SILENT KILLER
Hypertrophic Cardiomyopathy, The Silent Killer
Stefanie Varno
Concordia University
23 August 2013
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Running Head: HYPERTROPHIC CARDIOMYOPATHY, THE SILENT KILLER
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Hypertrophic cardiomyopathy (HCM), which is classified as a rare disease by the
Office of Rare Diseases of the National Institute of Health (NIH), causes atypical
enlargement of the muscle of the heart (Right Diagnosis, 2011 & Mayo Clinic, 2013). The
thickening of the heart muscle can cause great stress because it can make it difficult to not
only pump blood out of the heart but also to allow oxygenated blood to refill the heart
chambers (Medline Plus, 2013). HCM is an inherited condition and can affect anyone
(Medline Plus, 2013). HCM frequently goes undiagnosed since there are few symptoms, and
none that easily distinguish between HCM and any other cardiovascular disease (Mayo
Clinic, 2013). If symptoms do occur they commonly include chest pain, dizziness, fainting,
especially during exercise, fatigue, light-headedness, heart palpitations, shortness of breath
and arrhythmias (Medline Plus, 2013).
Hypertrophic Cardiomyopathy is caused by a mutation in the genes. Not only does
this mutation cause the heart muscle to grow unusually thick it can also cause the muscle
fibers to grow in an atypical arrangement known as myofiber disarray (Mayo Clinic, 2013).
These disorganized fibers then have the potential to lead to an irregular heartbeat known
as arrhythmia. People can have different causes and types of HCM. Most individuals with
HCM have HCM with obstruction meaning the septum in the ventricles is thickened (Mayo
Clinic, 2013). This thickening causes the heart to work harder to pump less blood. There is
also a nonobstructive HCM, which is when the muscle of the left ventricle becomes very
stiff and decreases the amount of blood that can be held; meaning less blood is being
pumped out with each contraction (Mayo Clinic, 2013). The severity of this disease varies
from person to person; some people can live without suffering any adverse reactions while
others may die from their condition.
Running Head: HYPERTROPHIC CARDIOMYOPATHY, THE SILENT KILLER
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HCM is typically inherited and it does not discriminate, it affects men and women
alike. It is the most common cardiac genetic disorder (Beutler and deWeber, 2009). The
prevalence of HCM is approximately one out of every 500 people or 0.2% of the population
(American Heart Association, 2013). This is equivalent to 544,000 people in the United
States (Right Diagnosis, 2011). This is a dramatic increase from the believed prevalence of
<1 in 100,000 in the 1980’s (Buetler and deWeber, 2009). Relatives of someone with HCM
are at greater risk and should follow proper screening protocols to facilitate early
detection. Children of those with HCM have a 50% chance of inheriting the mutation that
causes the disorder (Mayo Clinic, 2013). A dreaded risk for some of these individuals is
sudden cardiac death (SDC). In regards to the survival rate of HCM, two to three percent
die each year due to SCD and over ten years the risk of death increases to 20% or more
(Right Diagnosis, 2011).
Although deaths are rare, HCM is the leading cause of heart related sudden death in
people under 30 (Mayo Clinic, 2013). HCM is also considered to be the most common cause
of exercise related sudden death in young athletes (Basavarajaiah et. al., 2008). “HCM has
been positively identified in well over a third of cases (36%) of SCD in athletes under the
age of 30, and cited as a possible cause in another 8%” (Buetler and deWeber, 2009).
According to the NCAA each year nearly twelve collegiate athletes in the United States have
a fatal ending due to cardiac arrest (Medcalf, 2012). “Sometimes the first indication of a
problem is also the last” (Medcalf, 2012). It is a hard pill to swallow that with today’s
medical capabilities, the young age of the individuals and their apparent good health, there
is a disease that can end their careers and their lives instantly. Fred Hoiberg, a shooting
guard for the Minnesota Timberwolves, was diagnosed with a hidden heart condition like
Running Head: HYPERTROPHIC CARDIOMYOPATHY, THE SILENT KILLER
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HCM to which he refers to as “playing with a ticking time bomb in my chest” (Medcalf,
2012). Even though HCM may show no symptoms it can change the life of its victims when
it is discovered, like in Hoibergs case, once his cardiac ailment was found he was no longer
allowed to play basketball even though he felt as healthy as ever.
Figure 1. Causes of sudden cardiac death in young competitive athletes. (Atkins, et.
al., 1996)
Running Head: HYPERTROPHIC CARDIOMYOPATHY, THE SILENT KILLER
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A huge problem with HCM is that it is not screened for in routine sports physicals. It
is an unpredictable ailment and can be easily hidden for a long time. “Diagnosis is difficult,
and predicting which patients will develop severe complications and face the greatest risk
of premature SCD remains an inexact science” (Buetler and deWeber, 2009). Currently the
NCAA is conducting a study to see if there is a practical and cost-effective way to reduce the
number of incidents of sudden cardiac death in collegiate athletes (Medcalf, 2012). Dr.
Jonathon Drezner, President of the American Medical Society for Sports Medicine and chief
researcher of the NCAA funded study says that even with the implementation of a
screening tool, there would still be room for error, no program can be perfect.
The key to diagnosing HCM is the screening tool used. In the typical preparticipation sports physical the screening is very generic and is not set up to detect a
condition such as HCM since it has few if any distinctive symptoms. Unfortunately young
high school and college athletes are taken every year due to HCM. Only 20% of these
individuals have symptoms of HCM and majority of them don’t report it because they either
think it is normal or they are afraid of the consequences (Medcalf, 2012). One sign that
could possibly be found during a routine physical is a heart murmur, but that is only in
certain cases. If this is detected the athlete should be referred to his or he primary care
physician (PCP) or a cardiologist for further testing. The test most commonly used to
diagnose HCM is the echocardiogram (Echo). This test allows the doctor to see a picture of
the heart to view the thickness of the cardiac muscle, the blood flow and the functionality of
the valves (Mayo Clinic, 2013). Another key factor to look for is the pre-participation
questionnaire. The questionnaire should ask several questions which could lead to
referring the athlete for an echo. Those questions include:
Running Head: HYPERTROPHIC CARDIOMYOPATHY, THE SILENT KILLER
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1. Have you ever passed out or nearly passed out during exercise?
2. Have you ever passed out or nearly passed out after exercise?
3. Have you ever had discomfort, pain, or pressure in your chest during
exercise?
4. Does your heart race or skip beats during exercise?
5. Has a doctor ever told you that you have a heart murmur?
6. Has a doctor ever ordered a test for your heart (i.e. EKG, Echo)?
7. Has anyone in your family died for no apparent reason?
8. Does anyone in your family have a heart problem?
9. Has any member of your family or relative died of heart problems or of
sudden death before age 50?
According to Buetler and deWeber (2009), who listed these 9 questions from the American
College of Cardiology (ACC), American Acadamey of Family Physicans and other major
organizations, only 17% of high schools in America ask all of these questions in there preparticipation physical screening.
There is a debate as to whether all athletes should also have to undergo an
electrocardiogram (EKG) during the pre-participation physical as well. Some obvious
barriers include time and money. The EKG can help detect abnormalities with the heart but
is not a certain detector for HCM. Italy utilized a 12-lead EKG as an additional screening
measure for all high school athletes during their physical and has seen a 90% reduction is
sudden cardiac death in young athletes (Buetler and deWeber, 2009). There are many
different factors to consider when viewing these results and considering whether this
should be the standard in the United States. Those include not just the time and money but
Running Head: HYPERTROPHIC CARDIOMYOPATHY, THE SILENT KILLER
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the differences in the populations, the number of athletes, the need for trained
professionals to perform and interpret the results and the number and effect of false
positive tests (Buetler and deWeber, 2009).
Individuals with HCM can go on to lead normal lives given the proper diagnosis and
treatment early on. Education is key for these patients. Restriction from competitive sport
is common and the insertion of a defibrillator to shock the heart if arrhythmia occurs is also
a preventative measure. High school and collegiate athletes who die of SCD are difficult to
deal with due to the appearance of health, anything we can do to prevent these deaths in
the future should be considered.
Running Head: HYPERTROPHIC CARDIOMYOPATHY, THE SILENT KILLER
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References
American Heart Association (2013). Hypertrophic Cardiomyopathy. Retrieved from
http://www.heart.org/HEARTORG/Conditions/More/Cardiomyopathy/Hypertroph
ic-Cardiomyopathy_UCM_444317_Article.jsp
Atkins, Dianne L., Clark, Luther T., Crawford, Michael H., Douglas, Pamela S., Driscoll, David
J., Epstein, Andrew E., Maron, Barry J., McGrew, Christopher A., Mitten, Matthew J.,
Puffer, James C., Strong, William B. and Thompson, Paul D. (1996). Cardiovascular
Preparticipation Screening of Competitive Athletes. Circulation 94 (4), 850-856. Doi:
10.1161/01.CIR.94.4.850. Retrieved from
http://circ.ahajournals.org/content/94/4/850.full
Basavarajaiah, Sandeep, McKenna, William, Shah, Ajay, Sharma, Sanjay, Wilson, Matthew
and Whyte, Gregory. (2008). Prevalence of Hypertrophic Cardiomyopathy in highly
Trained Athletes. Journal of the American College of Cardiology, 51(10), 1033-1039.
Doi:10.1016/j.jacc.2007.10.055. Retrieved from
http://content.onlinejacc.org/article.aspx?articleid=1138778
Beutler, Anthony and deWeber, Kevin (2009). Hypertrophic cardiomyopathy: Ask athletes
these 9 questions. The Journal of Family Practice, 58 (11), 576-584. Retrieved from
http://www.jfponline.com/index.php?id=22143&tx_ttnews[tt_news]=174766
Mayo Clinic, 2013. Hypertrophic Cardiomyopathy. Retrieved from
http://www.mayoclinic.com/health/hypertrophic-cardiomyopathy/DS00948
Medcalf, Myron, 2012. ESPN Men’s Basketball. Taking a Closer Look at Heart Issues.
Retrieved from http://espn.go.com/mens-collegebasketball/story/_/id/8313100/when-hearts-young-athletes-fail-college-basketball
Running Head: HYPERTROPHIC CARDIOMYOPATHY, THE SILENT KILLER
Medline Plus, 2013. Hypertrophic Cardiomyopathy. Retrieved from
http://www.nlm.nih.gov/medlineplus/ency/article/000192.htm
Right Diagnosis (2011). Statistics about Hypertrophic Cardiomyopathy. Retrieved from
http://www.rightdiagnosis.com/h/hypertrophic_cardiomyopathy/stats.htm
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