What Is Cardiomyopathy?


Cardiomyopathy is a term used to describe diseases of the heart muscle that affect the heart’s ability to pump blood to the rest of the body. The three main types of cardiomyopathy are hypertrophic cardiomyopathy, dilated cardiomyopathy and arrhythmogenic right ventricular cardiomyopathy.1

This article will tell you everything you need to know about cardiomyopathy including the possible causes and risk factors as well as the symptoms, diagnosis and different types of treatment.

Types of cardiomyopathy

The three main types of cardiomyopathy are hypertrophic cardiomyopathy, dilated cardiomyopathy and arrhythmogenic right ventricular cardiomyopathy. 

Hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy occurs when the muscle wall of your heart becomes thickened which makes it harder for the heart to function normally and pump blood to the rest of your body. As the walls of the heart chambers thicken, the heart chambers reduce in size which means they cannot hold much blood and the walls cannot relax properly and can become stiff. The flow of blood through the heart may also be obstructed. This type of cardiomyopathy mostly affects the left ventricle which is the heart’s main pumping chamber. 

Like most types of cardiomyopathy, hypertrophic cardiomyopathy is known as an inherited heart condition which means it is a genetic condition that can be passed on through families. If you have a parent with the condition then you have a 50% chance of also inheriting the condition.1

For many people, hypertrophic cardiomyopathy is a condition that does not affect their daily life but for others it can be more serious. In fact, this type of cardiomyopathy is the most common cause of sudden death in both children and young athletes.1

Dilated cardiomyopathy

Dilated cardiomyopathy is a disease which causes the muscle walls of the heart to become enlarged and weaker. This affects the left ventricle of the heart which means that the heart cannot properly contract and pump blood to the rest of the body. As the condition progresses, dilated cardiomyopathy can also affect the right ventricle too. 

Research shows that dilated cardiomyopathy is one of the main causes of heart failure. As well as this, it increases your risk of heart valve problems, blood clots and an irregular heartbeat.1

This condition can affect both children and adults and for many people, the cause is unknown. However, common causes of this condition include inheriting a mutated gene, uncontrolled blood pressure, a heart valve problem, an unhealthy lifestyle, an underlying medical condition and a disease of the tissues or blood vessels. 

Arrhythmogenic right ventricular cardiomyopathy

Arrhythmogenic right ventricular cardiomyopathy (ACM) is a condition which occurs when the cells of the muscle tissue do not develop properly which causes the heart structure to weaken. This can cause muscle cells to die and fatty and fibrous scar tissue to replace dead muscle tissue. This condition can affect the heart’s ability to pump blood to the rest of the body and can lead to symptoms of heart failure.

ACM is an inherited condition caused by a mutation in one or more genes and can affect both teenagers and young adults.

Restrictive cardiomyopathy 

This is a rare type of cardiomyopathy that causes the heart muscle to become stiff and less flexible which means the walls cannot relax properly after contracting. This means they cannot expand and fill with blood between heartbeats which results in reduced blood flow from the heart. This can lead to symptoms of heart failure.

Restrictive cardiomyopathy is usually diagnosed in children but it can develop at any age. For most people, the cause of this type of cardiomyopathy is unknown although sometimes it can be inherited.

Causes of cardiomyopathy

Cardiomyopathy can both be caused by other heart conditions and circulatory conditions as well as inherited genes. This means a faulty gene that causes cardiomyopathy can be passed down to families. However, in many cases the cause of cardiomyopathy is unknown. 

Possible causes include:

  • High blood pressure
  • Abnormal heart rhythms
  • Heart valve disease
  • Heart tissue damage from a heart attack
  • Infections that cause inflammation of the heart
  • A buildup of iron in your heart (hemochromatosis)
  • A buildup of abnormal protein in your organs (amyloidosis)
  • Drinking too much alcohol

Signs and symptoms of cardiomyopathy

Some people with cardiomyopathy may not experience any symptoms or their symptoms may be mild. Others may get symptoms that worsen as time goes on and the condition advances.

Symptoms include:

  • Breathlessness
  • Lightheadedness
  • Swollen legs, ankles and feet
  • Bloated abdomen due to fluid buildup
  • Abnormal heart rhythm 
  • Fatigue
  • Chest pain or pressure 

Symptoms often get worse unless they are treated. If you are experiencing any of these symptoms, you should book an appointment with your GP or call 999 if your symptoms are severe.

Management and treatment for cardiomyopathy

Although cardiomyopathy cannot be cured, symptoms can be improved through different types of treatment. Not everyone with cardiomyopathy requires treatment as some people may have a mild form of the condition which they can control by making a few lifestyle changes.

Lifestyle changes including:

  • Eating a healthy diet and do regular, gentle exercise
  • Quit smoking
  • Avoid or reduce your intake of alcohol
  • Lose weight if you are overweight
  • Get enough sleep
  • Manage your stress
  • Manage and control any underlying condition e.g. diabetes

Medicines can also be used to treat cardiomyopathy which can lower blood pressure, correct an abnormal heart rhythm, improve blood flow, remove excess fluid from the body and prevent blood clots. This include:

  • Beta-blockers - to treat heart failure or correct an irregular heartbeat
  • Anticoagulants - to prevent blood clots
  • Diuretics - lower blood pressure by removing excess fluid from your body

There are also hospital procedures and surgeries available as treatments if required.

Hospital procedures include:

Diagnosis of cardiomyopathy

Cardiomyopathy can often be diagnosed through heart scans and tests, such as:1

  • Echocardiogram
  • Electrocardiogram (ECG)
  • MRI scan
  • Exercise tests
  • A genetic test - if you have been diagnosed with an inherited type of cardiomyopathy

Risk factors

There are various factors that can increase your risk of cardiomyopathy, including:

  • Long-term high blood pressure
  • Family history of cardiomyopathy or other heart conditions
  • Obesity
  • Long-term alcohol misuse
  • Other heart conditions - e.g. a heart attack, an infection in the heart or coronary artery disease
  • Certain drugs - cocaine, anabolic steroids and amphetamines 
  • Certain diseases - e.g. diabetes, thyroid disease, excess iron in the body (hemochromatosis), connective tissue disorders


Cardiomyopathy can seriously affect the heart by affecting the structure of your heart and reducing its ability to pump blood around the body and affecting the way the electrical system causes your heart to beat. This can lead to serious complications such as:


How can I prevent cardiomyopathy?

In most cases, there is no way to prevent cardiomyopathy. However, you can reduce your risk of cardiomyopathy and other heart conditions by following a healthy lifestyle. This includes:

  • Avoiding or limiting your intake of alcohol
  • Eating a healthy diet
  • Controlling high blood pressure as well as high cholesterol and diabetes
  • Exercising regularly
  • Getting plenty of sleep
  • Managing your stress

How common is cardiomyopathy?

Cardiomyopathy affects around 1 in 250 people in the UK.

What can I expect if I have cardiomyopathy?

All cases of cardiomyopathy are different. Some people do not notice many symptoms or they have mild symptoms whereas others have severe symptoms. When treated, most people with cardiomyopathy live long and healthy lives.

When should I see a doctor?

You should book an appointment with your GP if you are experiencing one or more symptoms of cardiomyopathy. If your symptoms are severe (e.g. difficulty breathing, chest pain or fainting) you should call 999 and seek emergency care.


In summary, cardiomyopathy is a disease of the heart muscle which affects the heart’s ability to pump blood around the body. The three main types of cardiomyopathy are hypertrophic cardiomyopathy, dilated cardiomyopathy and arrhythmogenic right ventricular cardiomyopathy. Most types are caused by an inherited gene that is passed on through families but other possible causes include high blood pressure, damage from a heart attack and abnormal heart rhythms. The possible treatment options for cardiomyopathy include lifestyle changes, medication and hospital procedures such as heart surgery or insertion of a pacemaker. All cases of cardiomyopathy are different but some people may have severe symptoms that cause further complications such as heart failure, heart valve problems, blood clots and cardiac arrest.


  1. Ciarambino T, Menna G, Sansone G, Giordano M. Cardiomyopathies: an overview. Int J Mol Sci [Internet]. 2021 Jul 19 [cited 2023 Apr 21];22(14):7722. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8303989/ 
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Suad Mussa

Bachelor of Science – BSc, Biology. Queen Mary University of London

Suad Mussa is a biology graduate with a strong passion for medical writing and educating the public about health and wellbeing.

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