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 cardio myopathy 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
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
Restrictive — Portions of the heart wall become
rigid and lose their flexibility. Thickening
often occurs due to abnormal tissue invading the
Normal Heart and Heart With Hypertrophic
Copyright © Nucleus Medical Media, Inc.
In many cases, the exact cause is not known. Possible
The cause of the initial damage is often not found, but
Ischemic heart disease with decreased
blood flow to the heart
Infections, usually viral
Chronic exposure to toxins, including
alcohol and some chemotherapy drugs
A rare complication of pregnancy or
childbirth (probably immune-related)
Rarely, other illnesses, including
rheumatoid arthritis, diabetes, or
Causes may include:
Inherited (sometimes present at birth but often
developing in teens)
Aging, associated with hypertension
This is usually related to another condition, such as:
Amyloidosis — protein fibers collect in the heart muscle
Sarcoidosis — small inflammatory masses (granulomas)
form in many organs
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
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 enlargement
Electrocardiogram — a test that records the
heart's activity by measuring electrical
currents through the heart muscle
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 cardiomyopathy
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 weight.
Eat a low-fat diet to minimize the risk and
extent of coronary artery disease.
Limit salt intake to decrease fluid retention.
Follow your doctor's advice for exercise. You
may need to limit physical activity.
Medications may include:
Diuretics — to eliminate extra fluid
ACE inhibitors — to help relax blood vessels,
lower blood pressure, and decrease the heart's
Hydralazine and isosorbide dinitrate — may be
used in addition to ACE inhibitors
Angiotensin receptor blockers—similar to ACE
Digitalis — to slow and regulate the heart rate,
and modestly increase its force of contractions
Beta blockers — to slow the heart and limit
Spironolactone — to improve the outcome in
people with dilated cardiomyopathy and advanced
Surgical options include:
A pacemaker may be implanted to improve
the heart rate and pattern.
For people with hypertrophic disease,
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
For those with life-threatening,
irregular heart rhythms, a cardioverter
defibrillator may need to be implanted.
A heart transplant may be possible for
otherwise healthy patients who do not
respond to medical treatment. Candidates
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 function.
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//
Braunwald E, Zipes DP, Libby P, et al. Heart Disease: A Textbook of
Cardiovascular Medicine. 6th ed. Philadelphia, PA: WB Saunders
Cecil RL, Goldman L, Bennett JC. Cecil Textbook of Medicine. 21st
ed. Philadelphia, PA: WB Saunders Company; 2000.
Dambro MR, Griffith JA. Griffith's 5-Minute Clinical Consult.
Philadelphia, PA: Lippincott Williams & Wilkins; 2001.
Echt DS, Packer D, Greer GS, Talajic M. Multicenter unsustained
tachycardia trial. N Engl J Med. 1999;341:1882-1890.
Goroll AH, Mulley AG. Primary Care Medicine. 4th ed.
Philadelphia, PA: Lippincott Williams and Wilkins; 2000.
Heart Failure Society of America 2010 executive summary of heart failure
practice guidelines. J Card Fail. 2010;16:475-539.
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