Cardiomyopathy
Cardiomyopathy is a progressive condition where
the heart muscle weaken and cannot pump enough blood to meet the
body's needs. There are four main types of this condition: dilated,
hypertrophic, restrictive and arrhythmogenic right ventricular
cardiomyopathies.
Dilated cardiomyopathy is the most common form
of this condition. Here, weak heart muscle cause blood to pool
in the ventricles or pumping chambers. As more blood fills the
ventricles, these chambers expand. Over time, the heart muscle
becomes stretched out or dilated, and becomes even weaker.
In hypertrophic cardiomyopathy, excessive muscle
thickness cause narrowing of the heart's chambers and prevent
adequate amount of blood from entering (and therefore being pumped
out of) the heart.
Restrictive cardiomyopathy is a rare condition
caused by infiltration of the heart's muscle with fibrous tissue
or abnormal materials.
Arrhythmogenic right ventricular cardiomyopathy
(ARVC) is caused by malfunction in the heart's rhythm due to fibrous
scar tissue formation in the heart muscle, especially in the right
ventricle.
Cardiomyopathy Symptoms
The symptoms of dilated cardiomyopathy include:
- Fatigue and weakness
- Shortness of breath, especially with physical activity
- Difficulty breathing while lying down
- Swelling of the leg and feet
Early cases of dilated cardiomyopathy may have mild or no symptoms.
These symptoms would then develop gradually over the course of
months or years. In cases of viral infection or pregnancy caused
cardiomyopathy, these symptoms can develop suddenly.
Hypertrophic cardiomyopathy often has no symptoms for years -
in many cases, sudden death during exercise is the only indication
of this heart disease. Indeed, hypertrophic cardiomyopathy is
the leading cause of sudden death among young athletes.
Diagnosis
Your doctor would perform the following tests to diagnose this
condition:
- Physical examination with a stethoscope
A heart murmur and crackling breath sound can sometimes be heard
with stethoscope.
- Chest x-ray
Enlarged heart and fluid accumulations can be seen in a chest
x-ray.
- Electrocardiogram or ECG
Change in heart's electrical pattern can be determined with
an electrocardiogram.
- Echocardiogram
This test can show dilated or poorly functioning heart muscle.
In cases of hypertrophic cardiomyopathy, echocardiogram test
should be performed after puberty, as the rate of the heart
muscle thickening often accelerates during puberty.
Causes of Cardiomyopathy
Dilated cardiomyopathy can be caused by:
- Viral infection
HIV infection and myocarditis or inflamed heart muscle caused
by viral infection can lead to dilated cardiomyopathy.
- Coronary artery
disease
- Heart attack
- Alcohol abuse
- Drug use, such as cocaine use
- Side effects of medications, such as chemotherapy and lithium
- Toxic metals, such as lead and mercury
- Endocrine diseases, such as thyroid disease
- Diabetes
- Heart valve abnormalities, such as pulmonary,
mitral valve,
and aortic valve
stenosis.
- Pregnancy
In rare cases, dilated cardiomyopathy can develop late in pregnancy
or within 6 months after giving birth.
- Genetics
The tendency to develop cardiomyopathy can also be inherited.
In most cases, however, the exact cause of this condition is
unknown, and thus it is medically classified as primary
or idiopathic dilated cardiomyopathy.
Hypertrophic cardiomyopathy is caused by thickening or overgrowth
of the heart muscle in a condition called idiopathic hypertrophic
subaortic stenosis or IHSS.
Restrictive cardiomyopathy is often the result of a disease called
amyloidosis, where protein deposits build up
in tissues in many of the body's organs. As these deposits continue
to build, they may interfere with the heart muscle's functions.
Other diseases that can cause restrictive cardiomyopathy include
rare metabolic diseases, such as Gaucher's disease, and endomyocardial
fibroses.
Treatment for Cardiomyopathy
In many cases, treatment of cardiomyopathy equals treatment of
the underlying cause. For instance, if diabetes and thyroid disease
are the causative factors that lead to dilated cardiomyopathy,
then treating these underlying cause can help the heart muscle
recover.
Medications for cardiomyopathy include:
- Anticoagulants to thin the blood and prevent clots that form
in arteries with weak blood flow.
- Beta blockers and calcium channel bockers to help regulate
heart rhythm.
- Diuretics to reduce blood pressure.
In some cases of hypertrophic cardiomyopathy, surgery can be
done to remove the overgrown muscle tissue.
Prognosis
In many cases, people with cardiomyopathies remain symptom-free
for a long period of time. Once the symptoms begin to show, however,
the heart function usually declines steadily.
In cases of hypertrophic cardiomyopathy, often there are no symptom
of this disease before sudden death.
Reference:
Cardiomyopathy
Association
