Heart-muscle disease can be a silent killer unless it’s diagnosed in time, says Dr Mel Wynne-Jones

Human heart

A condition called cardiomyopathy can cause sudden death at any age © iStock

Many people are unaware they have a condition called cardiomyopathy, that affects more than one in 500 of us.

It can cause sudden death at any age, and is a leading cause of death in people under the age of 35, but treatment can lead to a normal life expectancy.

Cardiomyopathy means damage to the heart’s muscular walls, which may become stretched, thickened, flabby or stiff, so the heart becomes less effective at pumping blood out to the body or lungs. The larger chambers (ventricles) are usually most severely affected.

What goes wrong?

In hypertrophic cardiomyopathy (HCM), heart muscles become thickened, jumbled and scarred.

It’s a genetic condition, with a 50% chance of passing it on to your children – broadcaster David Frost’s son, Miles, died of undiagnosed HCM at the age of 31.

Restrictive cardiomyopathy (RCM) limits heart muscle movement. It can be caused by chemotherapy, or a build-up of iron or proteins in rarer conditions (haemochromatosis, amyloidosis and sarcoidosis).

In dilated cardiomyopathy (DCM), heart muscles become stretched and thin. This can also be genetic with a 50% chance of passing it on, but may also be triggered by viruses, narrowed/leaky heart valves, untreated high blood pressure, too much alcohol, or pregnancy.

In the rarer condition – called arrhythmogenic right ventricular cardiomyopathy (ARVC) – fatty deposits build up between faulty muscle fibres. Takotsubo cardiomyopathy can develop suddenly; the left ventricle temporarily changes shape, often during acute physical or mental stress (‘broken heart syndrome’).

Warning signs

There may be no symptoms, but you may develop breathlessness, chest pains, palpitations (fast and/or irregular heartbeat), dizziness, faintness or blackouts, especially on exertion (which is often when sudden death occurs).

You may notice swelling of your ankles and/or tummy, and severe fatigue, too.

These may be due to less serious conditions, but you should see a doctor quickly, or even call 999 if they’re severe or sudden, as you’ll need tests (see the box on the right for details) and, perhaps, even immediate treatment.

Your treatment

There’s no current cure for cardiomyopathy, but it can be treated to prevent further damage and reduce your risk of sudden death. You may need drugs to control symptoms and to stabilise any abnormal heart rhythms, or a pacemaker or ICD (implantable cardioverter defibrillator) to monitor your heart and ‘shock’ it back to a normal rhythm if necessary.

Takotsubo cardiomyopathy has no specific treatment – you may be treated for a suspected heart attack – but it usually goes back to normal by itself.

Inherited risk

Cardiomyopathy isn’t the only genetic heart condition that can cause sudden unexpected death – some electrical abnormalities run in families, too. It can also develop from spontaneous gene mutations (new changes in DNA/genetic material), which can then be passed on.

If someone in your near family has one of these conditions, or has died young suddenly, speak to a GP or contact Cardiomyopathy UK (0800 018 1024; cardiomyopathy. org) or the British Heart Foundation (0300 456 8383; bhf.org.uk) for advice.

5 tests you may need

1 Checks on your pulse rate and rhythm, blood pressure and heart sounds.
2 An ECG – heart electrical tracing – which looks for abnormal electrical signals and heart muscle patterns.
3 An echocardiogram – ultrasound scan that shows your heart valves, muscles and blood flow, and what happens during each heartbeat.
4 Blood tests and other scans to look for other causes of your symptoms.
5 Genetic counselling and blood tests if you may be at risk.