It can affect the size, shape and thickness of your heart muscle, making it difficult for your heart to pump blood around your body. Over time, this can cause your heart to weaken and can lead to heart failure symptoms.
The 4 main types include:
Dilated cardiomyopathy
Dilated cardiomyopathy (DCM) affects the chambers of the heart, causing the walls of the heart to get bigger, stretched and thin. This makes it difficult for your heart to pump blood around your body. DCM can run in families and can also be caused by pregnancy and other conditions like uncontrolled high blood pressure. It can also occur as a side effect from certain medications, infections, drinking too much alcohol or illegal drug use. If left untreated, DCM can lead to heart failure symptoms. DCM is the most common type of cardiomyopathy and usually occurs in adults under the age of 50. Many people with DCM have no symptoms.
Hypertrophic cardiomyopathy
Hypertrophic cardiomyopathy (HCM) causes the walls of your heart muscle to thicken, get bigger and become stiff, making it difficult for your heart to pump blood around your body. It is diagnosed after excluding high blood pressure and valvular disease, which can also cause the heart muscle to thicken. The symptoms of HCM depend on how thick the heart muscle has become and where the heart muscle has gotten thicker. Some people may have no symptoms, but in general, people living with HCM notice their symptoms may worsen as they get older.
HCM is a genetic condition and people diagnosed with HCM are usually advised to have their first-degree relatives (parents, siblings and children) screened for the disease.
Arrhythmogenic cardiomyopathy
Arrhythmogenic cardiomyopathy (ACM) is a rare condition that causes the structure of the heart to dilate. This causes the heart to stop working properly. With ACM, fatty tissue replaces normal heart muscle causing the walls of your heart muscle to thin. This makes it difficult for your heart to pump blood around your body. ACM may also affect the electrical signals in your heart which can cause irregular heart rhythms (arrhythmias). ACM is usually a genetic condition, meaning it is passed down through families.
ACM used to be called arrhythmogenic right ventricular cardiomyopathy (ARVC) as it was thought to only affect the right ventricle chamber of your heart. It is now recognised that this disease can affect the left ventricle chamber by itself or both chambers of the heart.
Restrictive cardiomyopathy
Restrictive cardiomyopathy is a rare condition. Usually diagnosed in children, it can develop at any age. With this type of cardiomyopathy, abnormal tissue (like scar tissue) replaces the normal tissue in the heart muscle. This causes the heart muscle to become stiff and rigid. This means that the chambers of the heart cannot relax and fill with blood like they normally would. Restrictive cardiomyopathy causes a reduced flow of blood from the heart and, over time, can lead to heart failure symptoms and issues with heart rhythm. Sometimes it can be inherited, but often the cause of restrictive cardiomyopathy is unknown. The common known causes of restrictive cardiomyopathy are amyloidosis, sarcoidosis and haemochromatosis.
Because cardiomyopathy can be caused by genetics, it’s important to let your first-degree relatives (parents, siblings and your own children) know if you have been diagnosed as they will need to be screened for the condition as well. For more information on genetic testing and screening for cardiomyopathy, see our book Step by step through cardiomyopathy. Download it here.
Cardiomyopathy can also be caused by other conditions, including:
For some people, the cause of their cardiomyopathy is unknown. When this happens, it is called idiopathic cardiomyopathy.
As the condition advances, symptoms can start to appear. These usually vary from person to person and the type of cardiomyopathy that someone has.
Symptoms may include:
Symptoms of cardiomyopathy usually get worse if they are not treated. Speak to your doctor if you have any symptoms of cardiomyopathy. If you have trouble breathing, chest pain that lasts for a few minutes or gets worse, or if you collapse or faint, call 999/112.
Your doctor will also want to know if anyone in your family has been diagnosed with cardiomyopathy.
Diagnostic tests may include:
Blood test: Blood tests can check your kidney function to rule out issues like anaemia. They also measure the level of a peptide made in the heart called B-type natriuretic peptide (BNP). Your level of BNP might rise during heart failure, a common complication of cardiomyopathy. Blood tests can help diagnose your condition and monitor your progress.
Electrocardiogram (ECG): This test checks your heart for unusual rhythms and other abnormalities.
Echocardiogram (ECHO): An ultrasound of the heart that allows your doctor to check the size of your heart muscle and see how well it’s working. It also assesses how well your heart valves are working.
Cardiac MRI: A scan that takes detailed pictures of your heart. This scan can show how well your heart is working and help your doctor to see if there are any signs of inflammation, scar tissue or other abnormalities.
Exercise test: You may be asked to walk on a treadmill or cycle on an exercise bike while your heart rate is monitored with an ECG. This test gives your doctor information about your exercise tolerance, your symptoms and any problems with your heart rhythm during exercise.
Holter monitor: This is a wearable ECG monitor that continuously records your heartbeat over a longer period of time. You may need to wear one for 1-5 days depending on your symptoms.
Treatment will depend on the type of cardiomyopathy that you have been diagnosed with. Your treatment options may include:
You can read more about treatment and lifestyle changes in our book Step by step through cardiomyopathy. Download it here.
There is no cure for cardiomyopathy, but with treatment you can manage your symptoms and live a full life.
The Irish Heart Foundation provide a range of supports for people living with cardiomyopathy:
Contact our Nurse Support Line on (01) 668 5001 for more information or visit irishheart.ie.
Step by step through cardiomyopathy: Read our helpful guide for people living with cardiomyopathy, their families and loved ones.
Information and advice: Consultant Cardiologist, Dr Habita Sulaiman shares information about cardiomyopathy in this video.
Real Life Stories: View stories, lessons and advice from people who have survived stroke and heart conditions. Fiona Meagher shares her experience of living with dilated cardiomyopathy in this short video.
The Department of Clinical Genetics, Children’s Health Ireland at Our Lady’s Children’s Hospital, Crumlin provides genetic testing, genetic counselling and can also help with management of complex genetic conditions.
Cardiac Risk in the Young (CRY Ireland) provide peer support, counselling and family events for people living with cardiomyopathy.
Cardiomyopathy UK: A UK-based charity that supports people affected by cardiomyopathy.
Dillon Quirke Foundation: The Dillon Quirke Foundation aims to fund widespread cardiac screening for young people (aged 12-18) who are involved in sport.
The Mater Family Heart Screening Clinic: The Mater Hospital’s Family Heart Screening Clinic has been set up to cater for families affected by unexplained Sudden Cardiac Death in a young person. They also assess other family members and patients who have (or have a family history of) an inherited cardiac condition. Access to the clinic is by GP or self-referral.
