Dilated Cardiomyopathy

What is Dilated
Cardiomyopathy (DCM)?

Dilated cardiomyopathy (DCM) is a heart muscle condition that mainly affects the left ventricle of the heart. Inherited DCM is caused by a genetic change present at birth that can be passed down through a family, from parent to child.

It is important to note that there can be other causes of DCM that are not related to genetics, and instead are the result of environment or lifestyle factors. These environmental causes can include viral infections, autoimmune disease, prolonged use of alcohol or drugs, and pregnancy.

The information on this page applies to inherited DCM, but people with other types of DCM may also find some of this information useful.

The heart has four chambers. The top two chambers are called atria, and the bottom two are called ventricles. When blood returns from the body to the heart, it is first collected in the atria. The ventricles are the pumping chambers of the heart which send blood out from the heart to travel around the body. DCM affects the left ventricle, which is the main pumping chamber of the heart.

In a person with DCM, the left ventricle becomes stretched and enlarged (dilated). The stretched ventricle makes the walls around the left ventricle thinner and causes the muscle to weaken. This makes it harder for the heart muscle of the left ventricle to effectively pump blood out and around your body.

Family members are at-risk of developing DCM, so it is important to monitor the heart in these individuals.
More information for family members

DCM can be diagnosed by a cardiologist (heart doctor), and is usually diagnosed through testing that checks how well your heart is working. Your cardiologist may also repeat these tests as part of your ongoing management.

Testing may include, but is not limited to:

These changes in the heart can lead to a range of symptoms that will differ from person to person. Even people in the same family may experience different symptoms.

Some people with DCM may experience no symptoms while others may experience a range of symptoms.

Symptoms can include:

  • Shortness of breath (dyspnoea)
  • Swelling (oedema) in the feet, legs, or abdomen (belly)
  • Dizziness or lightheadedness (presyncope)
  • Chest pain (angina)
  • Fainting or loss of consciousness (syncope)
  • Fluttering / pounding in the chest (palpitations)
  • Abnormal heartbeats (arrhythmias)
  • Fatigue (lethargy)

In serious but rare cases, DCM can lead to heart failure, or sudden cardiac death. There can be no obvious symptoms prior to a sudden death.

Our bodies are made up of millions of cells. Each cell contains a copy of our genetic information. Our genetic information is the instructions for our body deciding how we will grow and function. Each instruction is called a gene. We have two copies of all our genes.

We share our genetic information with our families as we receive half our genetic information from each of our parents.

In DCM, one copy of a gene that is involved in your heart function may contain a genetic change (variant) that stops the heart from working as it should. The genetic variant changes the instructions sent out to the body and may cause your cardiomyopathy.

More information about inheritance

DCM is best managed by a team of healthcare professionals. This may include your GP, a cardiologist, a psychologist, and a cardiac genetic counsellor. Each member of your healthcare team plays a different and important role in caring for you, and your family. Management of your cardiomyopathy is very personal, your management plan will likely be different from other members of your family with the same diagnosis. There are a number of factors that go into personalising your management plan. Some of these are: age, current symptoms, how severe your disease is, your family history, and your specific type of cardiomyopathy.

Looking for more information:

Inheritance of Cardiomyopathy
Genetic Testing for Cardiomyopathy
Information for Family Members