Arrhythmogenic cardiomyopathy (ACM)

ACM explained

ACM is a condition where the cells in your heart muscle don’t stick together properly. The walls of your heart can become weak. And your heart might not be able to pump blood as well as it should. 

Your heart has four chambers. The top two are called the atria and the bottom two are called the ventricles. ACM can affect one or both of your ventricle chambers. 

Arrhythmogenic cardiomyopathy is a very rare condition. Most people with ACM can live their normal lives. 

ACM used to be called ARVC

Sometimes you might see ACM (arrhythmogenic cardiomyopathy) being called ARVC (arrhythmogenic right ventricular cardiomyopathy). The condition used to be called ARVC because it was thought to only affect your heart’s right ventricle chamber. 

But research has shown that the condition can affect either the left or right ventricles, or both. 

Rarely, ACM can also be called ARVD (arrhythmogenic right ventricular dysplasia).

Causes of ACM

ACM is caused by a problem with a type of protein in your heart muscle. These proteins are tiny particles in cells that act like strong glue. When the heart’s cells can’t glue together, the walls of the heart can become weak. Like a brick wall without cement. 

This means if one of your parents have ACM, you have a 50/50 chance of inheriting the faulty gene that could cause ACM. But even if you inherited the gene, you might not develop the condition. This is known as being a ‘carrier’. You can speak to your specialist about how that might impact you and your family. 

Contact our Genetic Information Service

When you or a member of your family are suspected to have an inherited heart or circulatory condition like ACM, it can feel worrying. If you have questions or concerns, the cardiac nurses in our Genetic Information Service can support you and help you understand your condition.

They can also explain why you might need to be assessed at a specialist genetics clinic and what you can expect to happen there. Our GIS team might be able to support your referral to a clinic too.

• Contact our Genetic Information Service for free

Symptoms of ACM

Some people living with ACM don’t experience symptoms. But you could have one or more of the following:

• palpitations (a pounding or fluttering feeling in your chest or neck)
• feeling lightheaded
• fainting
• feeling breathless or shortness of breath
• abnormal heart rhythms (when your heart beats too fast, too slow or irregularly)
• swollen ankles, legs or tummy area
• feeling pain or discomfort in your chest.

Some people living with ACM can feel more symptoms as they get older. 

Diagnosing ACM

ACM is usually diagnosed in tests that check how well your heart is working. You might be sent for these tests if your doctor thinks you could have ACM because of your symptoms, or because someone in your family has the condition. The tests can include:

• Chest x-ray – to see if your heart muscle looks bigger than it should be.
• Cardiac MRI scan – to check your heart’s walls and tissue for signs of damage.
• ECG (electrocardiogram) - to check the rhythm, rate and electrical activity of your heart.
• Exercise test – to check your heart’s rhythm and how your heart works when you’re physically active.
• Echocardiogram – an ultrasound of your chest to see if there’s a problem with the structure of your heart or your heart valves.

These tests are very common but speak to your doctor if you’re worried. 

Sometimes it can be tricky to diagnose ACM because the changes it causes to the heart muscle can be very small and hard to see. And the heart’s changes or symptoms can be similar to other conditions. This means doctors often have to rule out other possible conditions first.

Treating ACM

Although there’s no cure for ACM, treatments are used to help people with ACM live their normal lives. They help to reduce and control symptoms, and the risk of complications. This is done by helping your heart pump better and controlling abnormal heart rhythms. 

• Pacemaker – a small device fitted under your skin, usually near your collarbone, to only help your heart’s rhythm when it doesn’t beat like it should.
• ICD (implantable cardioverter defibrillator) - a small device fitted under your chest’s skin near your collarbone to continuously monitor your heart’s rhythm and treat dangerous, abnormal rhythms.
• Cardioversion – a short, common procedure to set your heart rhythm back to a normal pattern by sending a strong, electrical impulse to your heart muscle.
• Catheter ablation – a common, usually short, procedure to set your heart rhythm back to a normal pattern by blocking your heart’s electrical paths that aren’t working properly.

These treatments are very common for many heart and circulatory conditions. But having treatment can be worrying. If you’re concerned or have questions, your doctor  or nurse can support you. 

Your healthcare team will regularly look at how well your heart is working and talk to you about your treatment plan.

Risks and complications

Your treatment will help to reduce your risk of developing complications from ACM. The main complications can be:

• Heart block - when the electrical messages that tell your heart when to beat are delayed or blocked. This can cause your heart to beat too slow.
• Heart failure – when your heart doesn’t pump blood as well as it should.
• Sudden cardiac death (SCD) - when someone passes away suddenly because the heart has gone into a dangerous rhythm that caused a cardiac arrest. This is rare.

The risk of developing complications can be worrying. It’s important to understand that many people with ACM live their normal lives. Your healthcare team will create a treatment plan with you to manage and monitor your risk. But if you’re concerned, they can also support your emotional wellbeing.

Living with ACM

With the help of treatment, many people living with ACM enjoy their normal lifestyle. Your doctor might advise you to make some small changes to your lifestyle to help you manage your condition:

• Reduce your caffeine intake – caffeine can raise your heart rate and increase your blood pressure.
• Cut down on alcohol – alcohol can also raise your heart rate and increase your blood pressure. You might not need to stop drinking alcohol, but you should keep within the recommended guidelines.
• Take steps to stop smoking – if you smoke, quitting is the best thing you can do for your overall health. Start taking steps to quit today and keep your heart healthy.
• Eat a healthy, balanced diet – this can help you manage your weight and reduce the impact on your heart. It can also make you feel more energised and help you sleep better. See our tips for eating healthily around your routine, culture and weekly budget.

Working with ACM

Most people living with ACM can work. But your doctor might advise you to avoid any work that requires heavy lifting or strenuous physical activity. This is because it can make your heart work hard and it can cause symptoms like abnormal heart rhythms.

Find out more about working with a heart or circulatory condition.

Driving with ACM

If you don’t have symptoms, you should be able to drive a car. But you might not be able to drive lorries or buses. 

If you experience symptoms, you must not drive. This might only be temporary, but you should tell the DVLA. Your doctor and the DVLA can advise you. 

If your work requires you to drive, you might need to talk to your employer about your condition.

Find out more about driving with a heart or circulatory condition.

Exercise with ACM

You should be able to enjoy being physically active. But you should speak to your doctor first about what kind of exercise is safe for you to do. Your doctor might advise you to avoid high intensity exercises like running, swimming and football. This is to reduce the stress on your heart and the risk of triggering symptoms. 

But exercise can help to keep your body and mind healthy, and it can be fun too. There are many low intensity exercises you might be able to try, like:

• yoga
• tai chi
• taking the stairs instead of the lift
• hoovering or pushing a lawn mower
• a brisk walk with your dog or your friends.

Help us fight ACM

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Read more about how your donations will help us save lives from heart and circulatory diseases like ACM. 

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