'My healthy sister just never woke up'. The reality of Sudden Adult Death – and how to protect yourself

Patrick Mead had just finished his breakfast one Sunday morning in October 2019 when he noticed his sister, Lauren, hadn’t yet left her bedroom. The siblings worked together at a restaurant near their family home in Frome, Somerset; they had a shift that morning and Lauren was going to be late. Their mother walked upstairs to check on Lauren – and that was the point at which their “world just stopped”, Patrick remembers.

Lauren, the seemingly healthy 19-year-old with whom Patrick used to gossip every afternoon after school, had died in her sleep. Her parents laid her on her bedroom floor and gave her CPR. In a recording of a 999 call made that morning, Patrick’s mother can be heard sobbing down the phone, telling the operator: “She’s blue … she’s gone.”

The family did not yet not know it, but Lauren had fallen victim to Sudden Arrhythmic Death Syndrome, sometimes known as Sudden Adult Death Syndrome, or SADS. It is a poorly-understood condition in which a person dies from unexplained cardiac arrest where no cause can be found at post-mortem. It kills upwards of 500 people in the UK each year, most of whom appear outwardly healthy. It is far more likely to affect those aged below 35, for whom it is the third highest cause of death behind suicide and road accidents. Athletes are at particular risk. It is different to a heart attack, which occurs when an artery is blocked and usually affects middle-aged or elderly people.

Until recent decades, scientists knew very little about SADS. Deaths were described simply as “unexplained”; families were left without answers. But innovations in heart-screening technology have provided clues.

Although it is not always clear in individual cases, experts now think SADS is usually caused by an inherited heart condition like Long QT syndrome or Brugada syndrome. If you have one of these conditions, your heart will probably beat normally for most of your life. But there’s a small chance that at some point, without warning, the electrical signals that move around your heart will falter, causing the bottom of your heart to start beating very fast. Soon, the heart starts to quiver and becomes unable to pump blood.

If you have one of these conditions and it goes untreated, your likelihood of having a cardiac arrest in any given year could be as high as 10 percent, according to Katie Frampton, a specialist cardiac conditions nurse at London’s St George’s Hospital, one of the UK’s leading centres for identifying and preventing SADS. “It can be [triggered] by certain medications or certain circumstances. Often it happens just randomly, with no prior warning,” she says.

For the families left behind, the lack of answers can prove maddening. Patrick remembers the hours after Lauren’s death as a whirlwind of confusion. “Everybody was panicking. I didn’t really know what was going on.” His parents rang his school where he and Lauren had both been in Year 12. Soon, he had a string of shocked messages from friends. “I didn’t want to have to open them, because that’s when you acknowledge that something’s happened.”

With no answers as to Lauren’s cause of death, the confusion only continued in the following months – as chronicled in a new BBC Three documentary, Sudden Death: My Sister's Secret Killer. “You’d be sitting at home and you’d almost expect the door to open and [Lauren] to come through. There were a few times I’d think, ‘Oh I can’t wait to tell Lauren that’. And then, ‘Oh I can’t’. That was quite difficult.”

For those with an inherited condition, sudden cardiac arrest can strike anywhere, at any time. For Lauren, it came in her sleep. For 23-year-old Premier League footballer Fabrice Muamba, it happened 43 minutes into an FA Cup match at Tottenham’s White Hart Lane, in 2012, in full view of 36,000 spectators. Muamba’s heart stopped for 78 minutes; it's likely that he only survived because he received CPR within minutes from Tottenham’s five pitchside assistants. Of those who have a cardiac arrest outside hospital, only about one in 10 survive.

After a seemingly healthy adult dies from SADS, their immediate relatives are usually tested for genetic heart conditions. In about half of cases, doctors find a condition in another family member they think is responsible. Part of Frampton’s job at St George’s is to explain these statistics to distraught families – and guide them through the often frightening screening process.

“I'm generally the first person they speak to,” she says. “They have a huge amount of questions because obviously it's just so unfathomable that somebody who's young, fit, and healthy, and never had any health problems, suddenly just drops down dead. There's not really a clear process when someone dies like this. They've often been trying desperately to get in contact with people and, when they finally come through to us, I think they're just relieved that they've got somebody to speak to.”

Walking into St George’s last year with his parents for their tests, Patrick remembers being “probably the calmest out of the three of us. I just thought, ‘We're going to have to do the tests, so we can worry about the results after we've had them instead of thinking about what could or couldn't happen’. I just tried to look at things as logically as possible.”

When a patient is diagnosed with one of these conditions, it can usually be treated with medication, or a type of pacemaker known as an implantable cardioverter defibrillator which goes inside the body and uses electricity to restart the heart in the event of cardiac arrest. Patients might also be given an automatic external defibrillator – a potentially lifesaving electronic device now kept in many UK schools.

In the UK, patients are usually only screened for these conditions if their relative experiences an unexpected cardiac arrest, but some campaigners think heart screenings should be offered routinely – especially to young athletes. In Italy, screening of competitive athletes has been mandatory since 1982; since then, cases of young sudden cardiac death have dropped by 89 percent. In the UK, the charity Cardiac Risk in the Young (CRY) offers subsidised screening for anybody between 14 and 35, for £50 each. It is funded mostly by families affected by SADS. Screening is particularly recommended for any young people experiencing exercise-related chest pain, breathlessness or heart palpitations.

The UK’s National Screening Committee does not recommend routine screening for young people because they say there is not enough evidence that existing heart-screening technology correctly identifies problems (most studies of heart screening have been conducted on professional athletes, whose hearts are different to the general population, they say). Still, some UK private schools routinely offer heart screening to their pupils – a service not available in most state schools.

Ultimately, in Patrick’s case, doctors could not find any evidence of a genetic condition in the hearts of either of his parents. It proved something of a double-edged sword: a relief on the one hand, he says, but “with nothing showing up on our tests, you still don't know 100 per cent what happened to Lauren. Was it genetics, or was it something else? I guess we just don't know at the moment.” Scientists are currently examining a fragment of Lauren’s heart that was kept after her death; the family hope it will provide clues. If not, Patrick is hopeful that evolutions in science and medicine might one day provide the answer.

“It would be nice to find a definite cause. You don't completely move on from something like this. You’ve got to find a way to adjust and start living with it.”

You can watch Sudden Death: My Sister's Secret Killer on BBC iPlayer. CRY offers subsidised cardiac screening to those aged between 14 and 35