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.


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.


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.

Cardiomyopathy Association

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