The warning signs of sudden adult death syndrome have been pulled into sharp focus after Manchester United legend Mark Hughes’s son died from the rare condition.
Alex Hughes, 38, collapsed on the floor of his bedroom where he was found by his two sons on June 19, an inquest found this week.
The condition – medically known today as sudden arrhythmic death syndrome or SADS – was said to be the cause of his death.
SADS is the term for when someone dies unexpectedly from a cardiac arrest, the term for when the heart suddenly stops pumping blood around the body.
The condition can kill fit-and-healthy people – most often affecting under 35s – and is the cause of death of around 500 to 800 people in the UK every year.
However, many of its victims have no signs that they had suffered any heart problem after their passing.
Coroner Victoria Davies this week said that Mr Hughes suffered a ‘sudden death with a normal heart’.
Over time, experts have outlined some of the key conditions responsible for SADS – and the warning signs that thousands of Britons may need to look out for.
Alex Hughes’s cause of death was said to be sudden adult death syndrome, also known as sudden arrhythmic death syndrome or SADS
According to charity Cardiac Risk in the Young (CRY), the conditions responsible for SADS cause a cardiac arrest because they disturb the heart’s rhythm. This is medically known as ventricular arrhythmia.
The experts say this can even occur in people who have never had structural heart disease – the umbrella term for various heart defects including holes and damage.
Often, the trigger for SADS is a group of rare diseases known as ion channelopathies – rare genetic conditions, usually inherited from parents.
These affect the electrical functioning of the heart, without changing the structure of the organ.
The heart’s electrical function affects its rhythm – how fast it beats – but this stops after death.
According to the British Heart Foundation (BHF), this is one of the main reasons the cause of a cardiac arrest is hard to identify, and why SADS may be attributed to someone’s death.
It is believed that these ion channelopathies are the cause of around 40 per cent of SADS deaths.
And CRY say there are four in particular to look out for.
The first is Long QT Syndrome (LQTS), which they say is the ‘most common and best understood type’.
LQTS occurs in around one in every 2,000 people, meaning around 30,000 Britons could have the condition.
According to the NHS, LQTS can cause heart palpitations, the term for when the heart beats irregularly or faster than usual.
People with LQTS may be at risk of seizures or fainting and are at risk of cardiac arrest if it does not stop.
Usually, people who die from the condition do so in their sleep.
The health service say that around half of LQTS patients do not even have any symptoms.
However, it can be discovered with an electrocardiogram (ECG) – a test of the heart rhythm.
People with the condition are urged to eat foods rich in potassium like bananas, to stay hydrated, avoid sudden noises such as alarms, and to manage stress levels and anxiety.
They are told not to engage in difficult exercises and avoid drinks containing high amounts of caffeine.
The second channelopathy to be aware of, according to CRY, is Brugada Syndrome.
NHS guidance says around one in 5,000 people in England have the condition, which, like LQTS, is inherited, often symptomless and can be discovered with an ECG.
However, some of the symptoms – if there are any – can be slightly different.
As well as being at risk of fainting, heart palpitations and cardiac arrest, Brugada Syndrome patients may also feel dizzy and suffer with shortness of breath.
Sufferers are also likely to die in their sleep from the condition.
Brugada Syndrome patients are urged to check with a medical professional before taking any medication but are told to take paracetamol or ibuprofen if they are feeling unwell to prevent a high temperature, as this can cause problems with the heart’s rhythm.
Staying hydrated is also important.
They are told not to drink excessive alcohol and to avoid difficult exercise.
The third high risk condition is catecholaminergic polymorphic ventricular tachycardia (CPVT), which affects around one in every 10,000 Britons.
CPVT, which is also caused by genetics passed down by parents, shares largely the same symptoms as LQTS and Brugada Syndrome. They often appear in childhood.
It is said to be difficult to discover, with patients sometimes misdiagnosed with epilepsy.
According to the BHF, the heartbeat of a CPVT patient is usually quickened by emotional or physical stress.
Those who experience symptoms will also receive an ECG, and some are given a 24-hour heart monitor.
The last channelopathy linked to SADS is progressive cardiac conduction defect (PCCD).
It is not known how many Britons may be living with the condition.
PCCD typically causes the heart to beat ‘very slowly’ according to the BHF, who say this means electrical signals ‘cannot travel through your heart as they should’.
This can lead to cardiac arrest because not enough blood is flowing through the body.
PCCD can also cause dangerously fast heart rhythms. Shortness of breath, dizziness, fainting and blacking out are also warning signs.
That said, the BHF explain many people with the condition – also known as Lev-Lenegre’s Syndrome – ‘live normal lives’.
These four conditions are thought to be responsible for the bulk of SADS deaths, while structural heart disease is found to cause just 10 to 20 per cent.
Examples of these structural changes include hypertrophic cardiomyopathy – when the heart muscle is abnormally thick – and dilated cardiomyopathy, the term for when the heart’s chambers become stretched.
Arrhythmogenic right ventricular cardiomyopathy – when the heart muscle cells do not stick together properly – is also said to be a cause.
CRY say: ‘In some cases, the pathologist cannot confirm a diagnosis of structural heart disease – either because there is no evidence of it, or because there is not enough evidence and the heart is felt to be relatively normal. So the death will be recorded as SADS.
‘This may happen even in cases where evidence of inherited structural heart disease is subsequently detected in other members of the victim’s family.
‘The presence of very subtle structural heart disease in the victim may, however, have been enough to cause sudden cardiac death.’
It is believed that cot deaths – the sudden death of a baby – may be partly due to the same causes responsible for SADS.
