Dilated cardiomyopathy (DCM)

Dilated cardiomyopathy (DCM) explained

DCM is a disease of your heart muscle which enlarges your heart’s main pumping chamber (left ventricle), causing your heart’s muscle wall to stretch and become thin (dilate). This makes it harder for your heart to pump blood out of your heart and around your body.

Your left ventricle is almost always affected. Over time, it can affect your right ventricle (another chamber) too.

With DCM, the enlarged muscle walls give the heart a rounder shape instead of its usual cone shape.

Around 1 in 250 of the UK population has the condition.

DCM causes

For many people, the cause of DCM is unknown. For others, DCM runs in families and is caused by a change (mutation) to one or more of their genes. This can make them more vulnerable to getting the condition.

DCM can sometimes be caused by other things, like:

• a heart valve problem
• a viral infection if it causes inflammation of the heart muscle
• a heart attack
• congenital heart disease
• drinking too much alcohol
• using recreational drugs
• use of some cancer medications
• pregnancy if it causes peripartum cardiomyopathy.

DCM symptoms

Many people living with DCM might not notice any symptoms at first. The most common symptoms include:

• tiredness
• chest pain
• shortness of breath
• swelling of your feet, ankles, stomach and lower back
• palpitations (feeling your heartbeat pounding or beating more quickly than usual).

The symptoms of DCM often develop slowly and can usually be controlled with medication and other treatments after diagnosis.

DCM diagnosis

Your doctor might suspect that you have DCM if:

• you’re having symptoms
• you have a heart murmur (an unexpected or unusual sound from your heart)
• someone in your family has been diagnosed with DCM and you’re being sent for genetic test.

If your doctor suspects that you could have DCM, they’ll usually refer you to a cardiologist for a few tests and specialist advice. The most common tests for DCM are:

• An ECG. A simple and useful test which records the rhythm, rate and electrical activity of your heart.
• An exercise ECG. Also called a heart or exercise stress test, this common test looks at how your heart works when you’re exercising.
• An echocardiogram. A scan of the heart similar to ultrasound scanning used in pregnancy because it uses sound waves to build up a picture of your heart.
• An angiogram. A heart test that looks at the blood supply of your heart. It helps the doctor spot any narrowing inside the coronary arteries.
• An MRI scan. A type of scan that creates detailed images of your heart.

Genetic testing for DCM

DCM is sometimes caused by a change (mutation) to one or more of your genes. This means that it can be passed on through families. If your healthcare professional thinks that you have DCM, you may be offered a genetic test to find out.

If you're found to have a faulty gene, your healthcare professional may ask to talk to your close relatives, such as parents, siblings or children. This is because they may have also inherited the same gene.

If you're a parent, sibling or child of someone who has DCM, it's recommended that you're seen at a specialist inherited heart conditions clinic for an assessment and to talk about the option of genetic testing.

Get information and support about inherited heart conditions through the BHF Genetic Information Service. 

DCM treatment

There’s no cure for DCM. Most of the symptoms can be controlled by medication and other treatments to help you live your normal life. The type of medication or treatment you might have will depend on:

• your symptoms
• if the cause of your DCM is known
• if you have developed other complications or conditions because of DCM.

DCM can cause arrhythmias (abnormal heart rhythms), which make your heartbeat too fast, too slow or irregularly. The main arrhythmias DCM can cause are:

• atrial fibrillation (AF)
• ventricular tachycardias
• heart block.

People with DCM who develop an arrhythmia might need a small, implantable device fitted under the skin on their chest to help support their heart. There are different types of devices. Your doctor will suggest the type of device needed to treat your arrhythmia. The implantable devices are:

• Implantable cardioverter defibrillator (ICD). This monitors your heart rhythm and delivers an electrical shock to restore your heart’s normal rhythm if your rhythm becomes dangerous.
• Pacemaker. This monitors and paces your heart rhythm by delivering electrical impulses if your heart misses a beat or is beating too slowly.

An ICD is usually fitted first. Sometimes you may need both an ICD and pacemaker, which you can have as one device.

In some rare cases where a pacing device and medication haven’t worked, a heart transplant may be considered. Some people that need a heart transplant might also need a left ventricular assist device (LVAD) while they wait for the heart transplant. An LVAD will help your heart muscle pump blood out of your heart and around your body.

DCM complications

DCM can cause some people to develop other conditions, like:

• blood clots
• heart valve issues
• sudden arrhythmic death syndrome caused by a dangerous heart rhythm
• arrhythmias (abnormal heart rhythms).

Like DCM, if other conditions develop, they can usually be controlled with medication and other treatments to help you live your normal life.

Living with DCM

Many people with DCM feel fine and have little or no symptoms. Those who have symptoms find that they are managed well with treatment and they're able to have a good quality of life. However, some people have symptoms that get worse over time. It’s important that you let your healthcare professional know if this happens so that they can help you manage them.

You might have to make some small changes to your lifestyle. We’ve included some things to think about below.

Work

You should be able to continue to work, but you may not be able to do manual jobs which involve strenuous activity. Speak to your healthcare professional about the work you do. Find out more about work and a heart condition.

Staying active

You should be able to enjoy most activities, but not some competitive sports and high intensity exercise. It’s best to talk to your healthcare professional about the activity you’d like to do.

Driving

You should be able to continue to drive, but you might not be able to drive a lorry, bus, HGV or commercial passenger vehicle. Talk to your healthcare professional about this or visit the DVLA website.

Sex

You may be worried about having sex while living with DCM, but it’s just as safe to do as other kinds of physical activity. It’s important to know your limitations and do it at a level that’s comfortable for you, so you can enjoy a full and active sex life. Find out more about sex and heart conditions.

Healthy living

Having a healthy lifestyle can help reduce the effects of DCM symptoms and lower your risk of getting other health issues. Learn more cardiomyopathy and healthy living.

Emotional support

Living with a heart condition like DCM can be uncertain and emotionally challenging for you and your loved ones. Learn more about things like stress, loneliness and talking about a condition.

Heart Helpline and more support

If you have any questions or concerns, speak to your healthcare team. You can talk to them about anything, even if it feels uncomfortable or embarrassing. Most people feel much better once they do.

Here are some other ways you can get support:

• Learn more about DCM and get support through Cardiomyopathy UK.
• Speak to our cardiac nurses on Heart Helpline by phone, callback, email or online chat (Monday to Friday, 9am to 5pm).
• Contact us to talk to our customer care advisors, find your local BHF shop and for any comments, compliments and complaints you may have.
• Talk to others with heart conditions by joining a support group or online community.

Beat heartbreak from hypertrophic cardiomyopathy

Want to know how the British Heart Foundation is giving hope to those living with cardiomyopathies? CureHeart is harnessing the latest technologies to make a transformative advancement.

This research was only possible through generous donations from the public. Your donations help us fund hundreds of top scientists all over the UK, working on more than a thousand different research projects, but more still needs to be done.