Cardiomyopathy: symptoms, types, causes and treatment

Symptoms depend on the type and how much the heart is affected, and some people have none. The British Heart Foundation (BHF) says most people with hypertrophic cardiomyopathy (HCM) have no symptoms or feel stable throughout life, while others do have symptoms. Some people find that symptoms worsen in later life because the heart muscle has slowly become stiffer.

The NHS says dilated cardiomyopathy increases the risk of heart failure, which typically causes shortness of breath, extreme tiredness and ankle swelling. In hypertrophic cardiomyopathy it says heart changes can cause dizziness, chest pain, shortness of breath and temporary loss of consciousness.

• Chest pain.

• Light-headedness and fainting.

• Palpitations (feeling your heartbeat pounding or beating more quickly than usual).

• Shortness of breath.

• Fatigue (getting tired easily).

• Swelling of the legs, feet, ankles and abdomen.

Cardiomyopathy is a general term for diseases of the heart muscle. The NHS says the walls of the heart chambers become stretched, thickened or stiff, which affects the heart's ability to pump blood around the body. It can affect people of all ages.

There are several types, which behave differently. The table summarises those described by the NHS.

The NHS says most types of cardiomyopathy are inherited. It can also be caused by other conditions or risk factors, and for some people the cause is unknown. For dilated cardiomyopathy, the NHS lists inheriting a changed gene, an underlying medical condition, uncontrolled high blood pressure, an unhealthy lifestyle (including a lack of vitamins and minerals in the diet, drinking too much alcohol and using recreational drugs), a viral infection that inflames the heart muscle, a heart valve problem, diseases such as sarcoidosis, amyloidosis, lupus and vasculitis, and pregnancy.

The BHF says HCM is a genetic condition caused by a change in one or more genes, mostly passed on through families. A child of someone with HCM has a 50 percent chance of inheriting the condition.

The NHS says some cases can be diagnosed after various heart scans and tests. These include an electrocardiogram (ECG), an echocardiogram, an MRI scan, a heart rhythm monitor (24 or 48-hour ECG monitor), exercise tests and, sometimes, a detailed family tree drawn by specialists.

The BHF says the most common tests for HCM are a physical assessment, ECG, echocardiogram, exercise test and MRI scan. The doctor may mention obstructive HCM, where blood flow from the heart is reduced by the thickened wall, or non-obstructive HCM.

If you are diagnosed with an inherited type, the NHS says you may be advised to have a genetic test to identify the faulty gene. Relatives can then be tested for the same change and, if they have it, monitored and managed early. The BHF says if you are a parent, sibling or child of someone with HCM it is recommended that you are seen at a specialist inherited heart conditions clinic.

The NHS says there is usually no cure for cardiomyopathy, but treatments can be effective at controlling symptoms and preventing complications. Some types have specific treatments, and early diagnosis is very important. Not everyone needs treatment, and some people only have a mild form that they can control with a few lifestyle changes.

Lifestyle changes the NHS recommends include eating a healthy diet and doing gentle exercise, quitting smoking, losing weight if overweight, avoiding or reducing alcohol, getting plenty of sleep (and diagnosing and treating any sleep apnoea), managing stress and keeping any underlying condition such as diabetes well controlled.

Medicines may be needed to control blood pressure, correct an abnormal heart rhythm, remove excess fluid or prevent blood clots. The BHF lists diuretics, beta blockers and cardiac myosin inhibitors for HCM. Hospital procedures include alcohol septal ablation (an injection of alcohol to reduce part of the thickened septum) or a septal myectomy (surgery to remove part of it), ablation for heart rhythm problems, a pacemaker, or an implantable cardioverter defibrillator (ICD) to prevent a life-threatening abnormal heart rhythm. The NHS says as a last resort a heart transplant may be necessary.

The NHS says peripartum cardiomyopathy is rare and sometimes develops during pregnancy, or within 3 months of the baby's birth. It lists pregnancy among the things that can play a role in dilated cardiomyopathy. If you have a known heart muscle condition and are planning a pregnancy, discuss this with your heart specialist before conceiving.

Breathlessness, severe tiredness or ankle swelling that is new or getting worse in late pregnancy or after birth should be raised promptly with a midwife or GP.

The NHS says to always call 999 if you or someone else experiences chest pain and breathlessness like a heart attack, which is also how broken heart syndrome presents. The NHS says hypertrophic cardiomyopathy can cause temporary loss of consciousness and is the most common cause of sudden unexpected death in childhood and in young athletes, so fainting, especially during exercise, needs urgent medical assessment.

If you have been diagnosed, see your doctor regularly for monitoring, and tell them about any new symptoms. The NHS says people with severe HCM will need to see their doctor regularly, and that a doctor will advise about the amount of exercise you can do.

The BHF says many people with HCM feel fine and have little or no symptoms, and those who have symptoms find they are managed well with treatment and can have a good quality of life. You should be able to continue to work, although you may not be able to do manual jobs that involve strenuous activity.

The NHS says there is increasing evidence that prolonged, strenuous exercise can make symptoms of arrhythmogenic cardiomyopathy worse, so people with or at risk of it should discuss exercise in detail with their cardiologist.

On the NHS the GP is the first step, with referral to a cardiologist and, for inherited types, to a specialist inherited heart conditions clinic that offers genetic testing and family screening.

Some people choose to see a private cardiologist for scans such as an echocardiogram or MRI. In general terms the same tests apply. It is important that results are shared with your GP, that family members are told about screening and that long-term follow-up is arranged with a service that can offer genetic counselling.