Dilated cardiomyopathy is a serious condition in which
the heart muscle becomes weakened and loses strength to pump
blood throughout the body. The weakened heart cannot pump as
much blood out, so more blood remains in the heart after each
heartbeat. As greater amounts of blood fill and remain in the
heart's lower chambers (ventricles), the ventricles expand. In
time, the heart muscle stretches out of shape (dilates) and
becomes even weaker.
Most people with dilated cardiomyopathy eventually develop heart
failure. Heart failure does not mean the heart stops pumping;
rather, it is a condition in which the ventricles are not able
to pump enough blood to meet the body's needs for oxygen and
nutrients.
What causes dilated cardiomyopathy?
In the majority of cases, the cause of dilated cardiomyopathy is
not known (primary or idiopathic dilated cardiomyopathy). In
some cases you can inherit the tendency to develop dilated
cardiomyopathy from your parents.
There are specific factors that lead to heart muscle damage and
possibly dilated cardiomyopathy, including:
* Myocarditis, inflammation of the heart muscle caused by a
virus or an immune system problem. Infection with the human
immunodeficiency virus (HIV) can sometimes trigger the
development of dilated cardiomyopathy. 1
* Coronary artery disease (CAD) and heart attack. However,
CAD or heart attack does not lead to dilated cardiomyopathy in
every case.
* Excessive alcohol consumption; illegal drugs, such as
cocaine; medications, such as chemotherapy or lithium; and toxic
metals, such as lead or mercury.
* Pregnancy. In rare cases dilated cardiomyopathy develops
toward the end of pregnancy or during the first 6 months after
giving birth (peripartum cardiomyopathy). Why some women develop
peripartum cardiomyopathy is not known.
What are the symptoms?
Initially you may not have any symptoms or you may have mild
symptoms, such as fatigue or weakness.
Eventually, as your heart muscle weakens, you will develop heart
failure and feel shortness of breath, especially with activity;
fatigue; difficulty breathing while lying down; and leg
swelling. Symptoms can develop gradually, over months or years,
or they can develop suddenly, such as after a viral infection or
pregnancy.
How is dilated cardiomyopathy diagnosed?
Your health professional will review your medical history and
ask about recent illnesses, your alcohol and drug consumption,
and your family history of heart disease. Your health
professional will do a thorough physical examination, including
listening to your heart and lungs and examining your neck,
abdomen, and legs for fluid buildup. An electrocardiogram (ECG,
EKG), chest X-ray, echocardiogram, routine blood tests, and
further tests are usually needed to confirm a diagnosis.
What can I expect with dilated cardiomyopathy?
The underlying cause of dilated cardiomyopathy often affects
long-term survival. If the underlying condition is hard to
treat, heart failure may progress.
Sudden cardiac death is also a risk for people with dilated
cardiomyopathy, especially when some types of arrhythmias, or
abnormal heart rhythms, are present. 2
Of the women who develop dilated cardiomyopathy during pregnancy
(peripartum cardiomyopathy), about half will recover completely,
and the majority of the rest will improve. Once a woman develops
peripartum cardiomyopathy, she should not become pregnant again.
3
Improved diagnostic methods are allowing doctors to identify
cardiomyopathy earlier in the course of the disease, when it can
be better managed.
