Exams and Tests
Hypertrophic cardiomyopathy can be difficult to diagnose because it may not always
cause symptoms. The first step in diagnosing heart problems is a thorough
medical history and physical exam.
Your doctor will ask you about
any family history of hypertrophic cardiomyopathy or any heart disease. Your
doctor will also want to know if any relatives died an early and sudden death.
Sometimes when young people die of cardiac arrest from hypertrophic
cardiomyopathy, the disorder is not discovered because autopsies are not always
performed.
During the physical exam, your doctor will listen to
your heart with a stethoscope. If any extra or unusual heart sounds (gallops or murmurs) are heard, it may mean the
structure of the heart is abnormal.
You will usually have one or
more of the following tests to help your doctor diagnose and treat your
condition.
Electrocardiogram
An
electrocardiogram (ECG or EKG) measures the electrical
activity as it moves through the heart during contraction and relaxation. An
abnormal electrocardiogram may be the first sign of hypertrophic cardiomyopathy
in people who do not have any symptoms.
Echocardiogram
An
echocardiogram (echo) is a type of ultrasound exam
that uses high-pitched sound waves to create an image of the heart, which is
seen on a television screen. An echo is the main tool used to help doctors
diagnose hypertrophic cardiomyopathy and its severity.
Echocardiography can be used to:
- Estimate how well the lower left chamber of
the heart (left ventricle) is able to fill when the heart expands and measure
how much blood is pumped out as it contracts (ejection
fraction).
- Determine if the heart valves are functioning
normally.
- Measure overall heart size.
- Determine if the
heart muscle (myocardium), including the wall that separates the left and right
chambers of the heart, is unusually thick.
- Measure the degree that
blood flow is reduced during contraction (systole) if the wall that separates
the left and right chambers of the heart is abnormally thick.
Physical exam, electrocardiogram, and echocardiogram are
the best ways to diagnose hypertrophic cardiomyopathy. People with a family
history of sudden death, especially young athletes or those who are considering
starting an exercise program, should talk to their doctor about being tested
for hypertrophic cardiomyopathy. These tests may also help evaluate a person
who faints during strenuous physical activity.
Patients who are
considered to be low risk will not see their doctor as often as patients
considered at high risk, usually around every 3 years. An echocardiogram is
usually done again if your symptoms change or get worse.
Exercise test
Your doctor may have you run on a
treadmill or pedal a stationary bike while he or she looks at how well your
heart and lungs are working. An exercise test can give the doctor (and you) an
idea of how hard and how long you can exercise.
The results of an
exercise test may show that you have a higher risk for serious health problems
due to hypertrophic cardiomyopathy. Some doctors recommend an exercise test
before beginning any treatment for hypertrophic cardiomyopathy.
Chest X-ray
A
chest X-ray produces a photographic image of the heart
using rays of intense light energy that pass through the body and project an
image on a film. An X-ray can show information about the heart's size and
shape. In later stages of hypertrophic cardiomyopathy, an X-ray may reveal
signs of
pulmonary edema, which is fluid buildup in the
lungs.
Cardiac catheterization (cardiac cath) or coronary angiography
During a
cardiac catheterization or coronary angiogram, a long,
thin tube (catheter) is threaded through an artery or vein in the arm or groin
and into the heart to measure pressure in the heart chambers. Dye can be
injected through the catheter to see whether the coronary arteries are blocked,
how well the heart chambers are pumping, and whether heart valves are leaking.
Angiography may be done if the results of the echocardiogram are
inadequate. Angiography may also be used to check if surgery would be an option
for treatment of hypertrophic cardiomyopathy.
Genetic testing
Genetic testing can identify some
genes that are related to this condition. Many people who have relatives with
hypertrophic cardiomyopathy wonder if they or their children should have
genetic testing. So far, routine genetic testing is not yet practical because
there are so many possible abnormal genes that cause the disease. Genetic
testing is presently used in a small number of cases when the specific genetic
mutation in the affected relative has been identified.