Cardiomyopathy refers to heart muscle disease. The
damaged heart does not effectively pump blood. The
disease usually progresses to the point where patients
develop life-threatening heart failure . In addition,
people with cardiomyopathy are more likely to have
irregular heartbeats or arrhythmias .
There are two major categories of cardiomyopathy:
ischemic and non-ischemic cardiomyopathy. Ischemic
cardiomyopathy occurs when the heart muscle is damaged
from heart attacks due to coronary artery disease .
Non-ischemic cardiomyopathy, the less common category,
includes types of cardiomyopathy that are not related to
coronary artery disease.
There are three main types of non-ischemic
Dilated—Damaged heart muscles lead to an
enlarged, floppy heart. The heart
stretches as it tries to compensate for
weakened pumping ability.
Hypertrophic—Heart muscle fibers enlarge
abnormally. The heart wall thickens,
leaving less space for blood in the
chambers. Since the heart does not relax
correctly between beats, less blood
fills the chamber and is pumped from the
Restrictive—Portions of the heart wall
become rigid and lose their flexibility.
Thickening often occurs due to abnormal
tissue invading the heart muscle.
Normal Heart and Heart With
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In many cases, the exact cause is not known. Possible
The cause of the initial damage is often not
found, but may include:
Ischemic heart disease with
decreased blood flow to the
Infections, usually viral
Chronic exposure to toxins,
including alcohol and some
A rare complication of pregnancy
or childbirth (probably
Rarely, other illnesses,
including rheumatoid arthritis ,
diabetes, or thyroid disease
Causes may include:
Inherited (sometimes present at
birth but often developing in
Aging, associated with
This is usually related to another condition,
Amyloidosis —protein fibers
collect in the heart muscle
Sarcoidosis —small inflammatory
masses (granulomas) form in many
Hemochromatosis —too much iron
in the body
A risk factor is something that increases your chance of
getting a disease or condition.
Risk factors for cardiomyopathy include:
Family members with cardiomyopathy
Coronary artery disease
Symptoms vary, depending on the type of cardiomyopathy
and its severity.
Patients with hypertrophic cardiomyopathy often do not
notice any symptoms. Sudden cardiac death may be the
first indication of the condition.
In dilated cardiomyopathy, it may take years for
symptoms to develop. Blood clots may form due to the
abnormal pooling of blood in the heart. If a clot moves
to another part of the body ( embolism ), symptoms
associated with that organ (the brain, for example) may
be the first sign of the heart disease.
Cardiomyopathy ultimately leads to heart failure and the
Shortness of breath, often worse when
lying down or with exertion
Swelling in feet or legs
Irregular heart rhythm
The doctor will ask about your symptoms and medical
history. A physical exam will be done. The doctor will
listen to your heart with a stethoscope.
Cardiomyopathies often produce heart murmurs and other
abnormal heart sounds.
Tests may include:
Chest x-ray —a test that uses radiation
to take a picture of structures inside
the chest, used to look for heart
Electrocardiogram —a test that records
the heart's activity by measuring
electrical currents through the heart
Echocardiogram —a test that uses
high-frequency sound waves (ultrasound)
to examine the size, shape, and motion
of the heart
Blood tests—to check for damage to the
heart and other organs, and possibly for
the underlying cause(s) of the
Cardiac catheterization —a tube-like
instrument inserted into the heart
through a vein or artery (usually in the
arm or leg) to detect problems with the
heart and its blood supply
Heart biopsy —removal of a sample of
heart tissue for testing
When heart failure is due to blockages in the coronary
arteries, treatment directed at relieving these
blockages through angioplasty , stent placement , or
coronary artery bypass surgery may lead to improvements
in heart function and symptoms. For certain genetic
causes, other treatments may also lead to improvements
in function. For many patients, however, treatment is
aimed at relieving symptoms and prevent further damage.
Changes aim to eliminate anything that
contributes to the disease or worsens symptoms:
If you are overweight, lose
Eat a low-fat diet to minimize
the risk and extent of coronary
Limit salt intake to decrease
Follow your doctor's advice for
exercise . You may need to limit
Medications may include:
ACE inhibitors—to help
relax blood vessels,
lower blood pressure,
and decrease the heart's
—may be used in addition
to ACE inhibitors
blockers—similar to ACE
Digitalis—to slow and
regulate the heart rate,
and modestly increase
its force of
Beta blockers—to slow
the heart and limit
improve the outcome in
people with dilated
Surgical options include:
A pacemaker may be
implanted to improve the
heart rate and pattern.
For people with
doctors may remove part
of the thickened wall
separating the heart's
chambers. Surgery may be
needed to replace a
heart valve. Another
option is called alcohol
septal ablation. This is
a procedure to reduce
symptoms and improve how
the heart functions.
For those with
irregular heart rhythms,
defibrillator may need
to be implanted.
A heart transplant may
be possible for
patients who do not
respond to medical
often wait a long time
for a new heart. Those
waiting may temporarily
receive a ventricular
assist device, which is
a mechanical pump that
assumes some or most of
the heart's pumping
Aggressively treating hypertension, coronary artery
diseases, and their risk factors is the best way to
prevent most cases of cardiomyopathy. Other, less common
causes, however, are not preventable. People with a
family history of the disease should ask the doctor
about screening tests, especially before starting an
intense exercise program.
American Heart Association http://www.americanheart.org/
The Cardiomyopathy Association http://www.cardiomyopathy.org/
Heart Rhythm Society http://www.hrsonline.org/
Canadian Cardiovascular Society http://www.ccs.ca/index.php/en/
Canadian Family Physician http://www.cfpc.ca//
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What is cardiomyopathy? National Heart, Lung, and Blood Institute
website. Available at:
Published December 2008. Accessed July 13, 2009.
Reviewer: Michael J. Fucci, DO
Review Date: 09/2012
Update Date: 00/91/2012