Dilated cardiomyopathy

Overview

Dilated cardiomyopathy is a condition where the heart's main pumping chamber (the left ventricle) becomes stretched, thin, and weak. This means the heart cannot pump blood as well as it should, which can lead to heart failure and other problems.

Dilated cardiomyopathy is not rare, but it is not extremely common either. In the UK, it affects about 1 in every 2,500 people, though many cases may go undetected.

It can affect men, women, and children of all ages. It is more common in men and in people of African or African-Caribbean descent. Some cases run in families, while others are caused by other medical conditions or lifestyle factors.

Symptoms

Common symptoms

• Shortness of breath, especially during activity or when lying flat
• Feeling very tired or weak
• Swelling in the feet, ankles, or legs (oedema)
• Rapid or irregular heartbeat (palpitations)
• Dizziness or lightheadedness

Symptoms in children

• Breathlessness and difficulty feeding (in infants)
• Poor weight gain or growth
• Tiring easily during play or sport
• Swelling around the eyes or in the belly

Symptoms in older adults

• Worsening shortness of breath with usual activities
• Sudden weight gain from fluid buildup
• Increased need to urinate at night
• Confusion or feeling faint due to reduced blood flow to the brain

Causes

Main causes

• A viral or bacterial infection that damages the heart muscle
• Coronary artery disease (narrowing of the arteries that supply blood to the heart)
• High blood pressure that is not well controlled
• Certain genetic (inherited) changes that make the heart muscle weak
• Long-term heavy alcohol use or use of certain drugs (like cocaine)
• Some chemotherapy drugs or radiation therapy for cancer
• Complications during the last months of pregnancy or shortly after giving birth (peripartum cardiomyopathy)

Risk factors

• Having a family history of dilated cardiomyopathy or sudden cardiac death
• High blood pressure or diabetes
• Obesity
• Drinking too much alcohol over many years
• Using recreational drugs such as cocaine or amphetamines
• Having a history of viral infections that affect the heart

When to see a doctor

See a doctor urgently if:

• If you have chest pain, unexplained fainting, or severe shortness of breath — call your local emergency number immediately.
• If you have a very rapid or irregular heartbeat that does not settle in a few minutes, seek same-day medical care.

Book a routine appointment if:

• If you have ongoing symptoms such as fatigue, leg swelling, or breathlessness during normal activities, make an appointment with your healthcare provider.
• If you have a family history of dilated cardiomyopathy or heart failure, talk to your doctor about screening even if you feel well.

Diagnosis

Your doctor will ask about your symptoms, family history, and lifestyle. They will listen to your heart and lungs and may order several tests to see how well your heart is pumping.

Tests that may be done

• Echocardiogram (ultrasound of the heart) — the main test to see the size and function of the heart chambers
• Electrocardiogram (ECG) — records the heart's electrical activity
• Blood tests — to check for infections, kidney function, and other markers of heart strain
• Chest X-ray — to see if the heart is enlarged or if there is fluid in the lungs
• Cardiac MRI — detailed images of the heart muscle
• Stress test — to see how the heart responds to exercise
• Genetic testing — if a family cause is suspected

What to expect at your appointment

Most tests are painless and non-invasive. You may need to go to a hospital or cardiac clinic. The process usually takes a few hours or may be spread over a couple of appointments. Your doctor will explain each test beforehand.

Treatment

Treatment for dilated cardiomyopathy focuses on managing symptoms, improving heart function, and preventing complications. Your healthcare team will create a plan tailored to you, which may include lifestyle changes, medicines, devices, or surgery.

Self-care at home

• Take all prescribed medicines exactly as directed, even if you feel well
• Weigh yourself daily and report sudden weight gain to your doctor — it can signal fluid buildup
• Limit salt (sodium) in your diet to help reduce fluid retention
• Avoid alcohol and recreational drugs — they can make your heart weaker
• Avoid smoking and second-hand smoke
• Stay as active as your doctor advises — rest when you need to

Medical treatments

Medicines are often used to help the heart pump better, reduce fluid buildup, and control blood pressure. These include ACE inhibitors, beta-blockers, diuretics, and others. Your doctor will choose the best combination for you. In some cases, a small device called an implantable cardioverter-defibrillator (ICD) may be placed in the chest to prevent dangerous heart rhythms. A pacemaker may also be used to help the heart beat more regularly.

When is surgery considered?

In advanced cases where medicines and devices are not enough, a heart transplant may be considered. This is a major operation and only suitable for some. Less often, a special pump called a left ventricular assist device (LVAD) can be implanted to help the heart pump blood while waiting for a transplant or if transplant is not an option.

Living with this condition

Living with dilated cardiomyopathy means paying attention to your body and working closely with your healthcare team. Many people manage well with regular check-ups and a healthy lifestyle.

Lifestyle tips

• Follow a heart-healthy diet low in salt and saturated fats
• Stay active with your doctor's guidance — gentle activities like walking or swimming are often good
• Keep a healthy weight to reduce strain on your heart
• Get enough rest and avoid extreme physical exertion
• Limit alcohol and avoid smoking or recreational drugs

Diet and exercise

A balanced diet with plenty of fruits, vegetables, whole grains, and lean protein is recommended. Limit processed foods and salty snacks. Your doctor or a dietitian can give you specific advice. Regular, moderate exercise (like brisk walking for 20–30 minutes most days) can improve your heart health, but always check with your doctor before starting a new exercise programme.

Mental health and emotional wellbeing

Living with a chronic heart condition can be stressful and may cause anxiety or depression. It is normal to feel worried or down at times. Talk to your doctor — they can offer support, counselling, or refer you to a mental health professional. Support groups can also help you connect with others who understand.

Prevention

Not all cases of dilated cardiomyopathy can be prevented, especially if caused by genetics. But you can lower your risk by controlling high blood pressure, avoiding heavy alcohol use and recreational drugs, getting regular exercise, eating a heart-healthy diet, and keeping a healthy weight.

Vaccines

Staying up to date with vaccines, including the flu vaccine and pneumonia vaccine, can help prevent infections that might stress your heart. Ask your doctor if these are right for you.

Screening programmes

If you have a close family member with dilated cardiomyopathy, your doctor may recommend regular heart tests (such as an echocardiogram) even if you feel well. Early detection can help start treatment before symptoms appear.

Complications

If left untreated

• Heart failure — the heart cannot pump enough blood to meet the body's needs
• Arrhythmias (irregular heartbeats) that can be dangerous
• Blood clots that can lead to stroke or pulmonary embolism
• Sudden cardiac arrest — the heart stops beating suddenly

Long-term outlook

Dilated cardiomyopathy is a serious condition, but with modern treatment many people live for many years with a good quality of life. The outlook depends on the cause, how early it is diagnosed, and how well you follow your treatment plan. Research continues to improve treatments and outcomes. Your healthcare team can give you a better idea of what to expect based on your individual situation.

Find support

International organisations

• World Heart Federation
• Cardiomyopathy UK

Local organisations

• British Heart Foundation · United Kingdom

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