Restrictive Cardiomyopathy

What is Restrictive
Cardiomyopathy (RCM)?

Restrictive cardiomyopathy (RCM) is a heart condition that stiffens the muscle of the heart. The stiffened muscle makes it harder for the heart to fill with blood and contract (squeeze) to pump blood throughout the body.

RCM can be caused by genetics (inherited), or from other conditions such as amyloidosis, or haemochromatosis. Inherited RCM is caused by a genetic change present at birth that can be passed down in families.

The information on this page applies to inherited RCM but people with other types of RCM may 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. In a person with RCM, the muscles in the heart are replaced with scar tissue, stiffening the muscle, which restricts movement of the heart. RCM affects the muscles at the bottom of the heart (ventricles). 

The stiffened muscle affects the heart in two ways:

  1. The heart cannot relax completely, which limits the amount of blood that enters the ventricle. The reduced volume of blood entering the ventricle means there is less blood being pumped around the body
  2. In some cases of RCM, because the heart muscle is scarred, it can cause unusual or irregular heart rhythms.
Family members are at-risk of developing RCM, so it is important to monitor the heart in these individuals.

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

Some people with RCM may have no obvious 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)
  • Fast or irregular heartbeat (arrhythmias)
  • Fatigue (lethargy)

RCM 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:

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 RCM, 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.

RCM 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.