What is cardiomyopathy?

Cardiomyopathy is the general term used for a group of heart diseases caused by abnormal heart muscle. Cardiomyopathy is different to most other types of heart disease in that it has different causes.

There are several types of cardiomyopathy, with different causes.

  • Dilated cardiomyopathy – The heart is enlarged and dilated, causing poor pumping of the left ventricle or both ventricles. It is often associated with viral infection, autoimmune disease, heavy alcohol use or pregnancy.
  • Hypertrophic cardiomyopathy – The left ventricle is enlarged. Sometimes the right ventricle is enlarged too. There is often a family history of the disease.
  • Restrictive cardiomyopathy – The heart muscle becomes stiff, restricting the filling of one or both ventricles. It might be associated with other diseases, such as amyloidosis or endomyocardial disease.
  • Arrhythmogenic right ventricular cardiomyopathy – The muscle of the right ventricle is progressively replaced with fibrous and fatty tissue. A family history is common. Sometimes it affects the left ventricle too.
  • Ischaemic cardiomyopathy – This occurs when a person has had multiple heart attacks, which cause a part of the heart muscle to die and scar tissue to form, affecting the pumping action of the heart.
  • Unclassified cardiomyopathy – There are other types of cardiomyopathy that don’t fit into the categories listed.

What is the cardiovascular system?

The cardiovascular system is made up of the heart, lungs and blood vessels, all working together. It moves blood around the body. The blood carries vital nutrients, gases and hormones.

Read more about how the cardiovascular system works.

What are the signs and symptoms of cardiomyopathy?

The signs and symptoms of cardiomyopathy include:

  • shortness of breath (especially when lying down), due to collection of fluid in the lungs
  • heart palpitations
  • dizziness
  • cough
  • loss of appetite
  • tiredness, especially when exercising
  • increased weight and swelling of hands, legs or feet due to fluid retention
  • low blood pressure.

How is cardiomyopathy treated?

A variety of drug therapies are used to treat cardiomyopathy:

  • angiotensin converting enzyme (ACE) inhibitors – decrease the workload of the heart by lowering blood pressure and preventing fluid retention
  • diuretics – increase urine production to treat fluid retention
  • vasodilators – dilate blood vessels, which decreases the workload of the heart
  • beta blocking agents – slow the heart rate, decreasing the workload of the heart
  • antiarrhythmic drugs – keep the heart in a normal heart rhythm
  • inotropic drugs – strengthen heart contraction.

People with cardiomyopathy might also be treated with oxygen.

What happens in intensive care?

People who have mild to moderate symptoms of cardiomyopathy can generally be managed by the cardiac team in a coronary care unit. However, those with severe symptoms may need the full support of an intensive care unit (ICU). Here, they will be closely monitored by the team of doctors and nurses. Tests and procedures that may be done in ICU include:

Useful links

Publication details

Version 1.1. First published 2015. Next review 2023.


The information on this page is general in nature and cannot reflect individual patient variation. It reflects Australian intensive care practice, which may differ from that in other countries. It is intended as a supplement to the more specific information provided by the doctors and nurses caring for your loved one. ICNSW attests to the accuracy of the information contained here but takes no responsibility for how it may apply to an individual patient. Please refer to the full disclaimer.