Before Alexandra Thoms goes to sleep, she puts together a flat-pack dining table with her father, Gordon. She needs the table for her otherwise sparse two-bedroom Melbourne apartment which she has moved into just weeks earlier.
At 23, Alexandra has met the milestones of an ambitious life at lightning speed. She is well travelled, has earned a double university degree and a graduate job at Deloitte. She is healthy; an avid skier and gymgoer. Now, she is also a homeowner. She didn’t have a formal housewarming, though, as most of her friends still live at home.
Alexandra is excited about her independence but, even after moving out, she regularly goes to her parents’ home nearby armed with ingredients and a meticulously researched new recipe to make them dinner.
She likes to watch Australian rules football with her dad.
On the evening of the flat-pack table, she sends her parents a picture of the food she prepared for dinner. She goes to bed, places her phone next to her pillow and falls asleep for the last time.
It is Sunday 27 August 2023.
When a heart’s electrical signals are firing correctly, the body’s most important muscle beats in rhythm.
Lub-dub, lub-dub, lub-dub.
During malfunction, it quivers, and oxygen-rich blood is no longer pumped to vital organs, including the brain.
Lub-dub, lub-uh-dub … l-l-l-l, lub-d-d-d.
And when it doesn’t self-correct?
Lu- ... du-b-b-b … b … b …
Sudden cardiac arrest kills millions of people around the world each year.
Among those, every week in the UK, at least 12 seemingly healthy people aged 35 and under die from undiagnosed heart conditions. In the US, about 2,000 people aged under 25 die each year of sudden cardiac arrest. Studies suggest that, on average, one person under 35 experiences a sudden cardiac arrest every day in Australia. Most die.
There was 17-year-old Edward Millear, who died last year after rowing training on the banks of the Yarra River in Melbourne. Joshua Oguns, a 14-year-old schoolboy from Canberra, succumbed during a game of basketball. Fifteen-year-old Perth schoolboy Kent Yamazaki died playing tennis.
The fatality rate for sudden cardiac arrest is extreme, with studies putting it at 90%. It is then classified as a sudden cardiac death. Over the past 50 years, public health campaigns and advances in screening and treatment have led to rates of cardiovascular disease death dropping by 80%. Over the same period, experts say, the rate of sudden cardiac death – an unexpected cardiac death that occurs within an hour of first symptoms – among young Australians has remained virtually unchanged.
Statistically speaking, it’s a rare cause of death. But when it comes to children and young adults, it ranks among the leading causes of fatalities, surpassing deaths from car accidents and various forms of cancer.
“It’s just such a shock to the families,” says André La Gerche, an academic cardiologist and the head of the Heart Laboratory, supported by St Vincent’s Institute of Medical Research and the Victor Chang Cardiac Research Institute. “The child goes off to school and doesn’t come home, or goes to bed and doesn’t wake up. They go from being perfectly well to not being there at all.
“It’s near the top of the reasons why a young person dies, and even when there’s a high‑profile case, it’s often soon forgotten.”
La Gerche, who chairs the Australian Sudden Cardiac Arrest Alliance, says research is underfunded and public awareness is low, even in the broader medical community.
“Even professionals sort of fall back on the idea that young people don’t die very often.”
Alexandra Thoms speaks to her parents, Gordon and Bronwyn, every day. She is usually the one to phone first.
On Monday 28 August 2023 she doesn’t call.
Gordon and Bronwyn try calling her. No one picks up.
They think Alexandra must be unwell. At night-time, there’s still no answer. They start to worry.
The exact cause of sudden cardiac arrest often differs but there is one element that characterises them all: an immediate loss of consciousness.
“A sudden cardiac arrest is dramatic,” says Elizabeth Paratz, a cardiologist at St Vincent’s Institute of Medical Research and the Victor Chang Cardiac Research Institute.
“That’s when the heart stops suddenly and you need resuscitation. It’s an endpoint. The heart has stopped, and it can stop for a whole heap of reasons.”
Cardiac death in children is typically caused by inherited conditions – arrhythmias – that interfere with the tiny impulses that tell the heart muscle to squeeze. In older teenagers and young adults, inherited structural abnormalities – cardiomyopathies – are more prevalent. They can also cause an electrical short-circuit or pump failure.
But forensic pathologists conducting autopsies on young people often find a heart without an obvious flaw. The cause is considered to be “unascertained”; a classification given to about 40% of fatal cases.
“The younger you go, the more likely it is that the heart will look entirely normal and you won’t find a reason,” Paratz says.
For families mired in grief after the loss of a child to sudden cardiac death, there’s an extra layer of pain and confusion when a genetic cause is identified – what does it mean for younger brothers, sisters or other family members?
The prevalence of cardiac arrest rises as lifestyle factors, rather than genetics, become the dominant risk. Towards middle age and beyond, the likely cause of heart failure shifts to coronary artery disease, whereby cholesterol deposits are often the culprit.
This can lead to cardiac arrest but, more typically, a blockage in a coronary artery manifests in chest pressure, pain and breathlessness. This is a heart attack; a person may clutch at their chest but usually remains conscious and can seek help.
Most young people facing sudden cardiac arrest are not afforded that time. Sometimes, though, help comes before it’s too late.
On 12 June 2021, the Danish footballer Christian Eriksen was playing against Finland in the opening game of the European Championship. The midfielder was moving into an attacking position to receive the ball from a throw-in when he stumbled and fell face-first into the turf.
He didn’t try to break his fall. To thousands watching in the stands and on live TV, it looked as though life had abandoned him before he hit the ground.
Eriksen received almost immediate CPR and an electric shock from a defibrillator, and survived.
He collapsed again this month – on 7 June 2026 – during an international match. This time Eriksen quickly regained consciousness after the implantable cardioverter defibrillator inserted in his chest in 2021 returned his heart back into rhythm. He even walked off the field.
“The paradox of exercise,” says Belinda Gray, director of the genetic heart disease clinic at Royal Prince Alfred hospital, “is that it is protective for your overall cardiovascular risk, but there is also an increased risk of sudden death for elite athletes.” About 10% to 15% of sudden cardiac deaths occur during or immediately after exercise.
In Australia charities including the Heartbeat of Football – founded by the sports broadcaster Andy Paschalidis after seeing a teammate die on the pitch – have been pushing for the installation of defibrillators in community sporting grounds. Widespread automated external defibrillator (AED) availability could push cardiac arrest survival rates from 10% to about 20%, according to cardiologists interviewed by Guardian Australia.
On a cool winter evening in August 2024, then 12-year-old Xavier Arruzza was at soccer training at the Eschol Park football club in Sydney’s south-west.
Just after 9pm, following an intense cardio session, Arruzza collapsed. Bystanders initially thought it was an asthma attack but quickly discovered he had no pulse.
A club member started CPR before Nick Beashel, a trained volunteer alerted via the GoodSAM app, took over the resuscitation effort. Another person rushed the club’s AED to the fallen child.
Three shocks. Thud, thud, thud.
And then: lub-dub, lub-dub, lub-dub.
While state governments across Australia have supported AED rollout through grants, South Australia is the only one to make them mandatory in a range of public buildings and facilities. A Heartbeat of Football board member, Angelo Tilocca, says every state and territory should follow South Australia’s lead and that every school child and young adult should be trained to perform CPR and use a defibrillator.
About half of all European Union countries require citizens to complete CPR training, which includes defibrillator use, as a prerequisite for obtaining a driving licence. Many countries, including Japan and Sweden, provide comprehensive training at school.
I ask Xavier’s mother, Rose, how her son is going. He is, she says, a typical 14-year-old boy.
“I count my blessings every day while also banging my head against the wall,” she says, smiling.
“Without the defibrillator, I don’t think he’d …
“I am one of the lucky ones, and he is one of the lucky ones.”
But defibrillators can’t save everyone.
On Tuesday 29 August 2023, Gordon and Bronwyn drive to Alexandra’s apartment. The door is locked and some deliveries are outside, untouched. They call the police and fire brigade. The door is knocked down and the police go in.
A young police officer comes out of Alexandra’s apartment and looks at Gordon. “I’m so sorry,” he says.
“They didn’t want us to go in there but we went in and saw our baby girl,” Gordon recalls.
She is lying on her bed in her pyjamas. She looks peaceful.
“It was clear she had instantly passed away,” he says. “No struggle. We wanted to go in and see her. That’s a memory we will unfortunately have to live with for the rest of our lives.”
Alexandra Jane Thoms died in her sleep from an undetected arrhythmogenic cardiomyopathy, an inherited condition in which the heart’s electrical signals can misfire. About one-third of sudden cardiac deaths take place while people are sleeping, due to the simple fact that we spend about one-third of our lives asleep.
Gordon says while nothing can bring his daughter back, sudden cardiac arrest needs to be taken more seriously.
“This is not about blame,” says Gordon, who set up Alexandra’s Mission, a charity designed to help prevent cardiac deaths in young people. “It’s about leadership, and recognising sudden cardiac arrest for what it is – a major, preventable public health emergency.”
In late 2021, nine-month-old Sonny Green showed mild symptoms of gastro.
Danielle, his mother, thought she was being overly cautious as a first-time parent. It was rare for Sonny to be out of sorts; he was almost always content, and loved sharing his snacks with the family’s jack russell. This was Sonny’s first real illness in his short life so she took him to the local emergency department.
Shortly after arriving, Sonny went into cardiac arrest and died.
The cause of death was marked unascertained.
A year later, Danielle Green gave birth to a daughter, Airlie, whom she described as the family’s “heart healer”.
At five months old, Airlie showed mild symptoms of gastro and went into cardiac arrest. She survived and had a defibrillator implanted. She grew older, became a toddler who loved Sesame Street’s letter and number of the day and the “wiggle wiggle” dance.
At 18 months Airlie contracted gastro again and suffered cardiac death.
How do you begin to process that?
“Some days I wake up and I just think that this isn’t my life, and it isn’t my story, and you kind of continue on,” Green says.
“You have to compartmentalise your life. Sharing our story and talking about Sonny really opens people’s eyes to what can just happen to your family because my children were healthy, and developing as expected, and meeting all their milestones.”
It was only after Airlie suffered her first cardiac arrest that medical teams considered genetics were at play. Airlie had a rare genetic disorder called PPA2 which is known to cause lethal cardiac failure, often triggered by viral illnesses such as gastro. In adolescents or young adults, even the smallest intake of alcohol can be the fatal trigger.
Sonny’s postmortem samples were tested. He had it too.
“It makes me think, how many deaths are classified incorrectly?” Green says.
The absence of genetic testing after the unexplained death of a young person can lead to significant consequences for others on their family tree. This is particularly true for conditions like PPA2, where people who unknowingly carry the gene mutation survive common childhood illnesses, only to succumb after they take their first drink of alcohol.
Green has been lobbying policymakers to mandate genetic testing in the postmortems of young people when the cause of death is unexplained.
“Everyone in the medical field – geneticists, cardiologists, paediatricians – they’re all pushing for genetic testing to assist with diagnosis,” Green says. No Australian state government has mandatory genetic testing in such cases.
Richard Bagnall, the head of the Centenary Institute’s centre for cardiovascular research, says targeted postmortem genetic testing offers a critical way to identify at-risk people.
“If you find a variant that caused the death, you can answer the two questions that almost every family will ask: why did this happen and how can we prevent it from happening again to other people in the family?”
Once identified as at risk, preventive measures then open up; including periodic cardiac screening, changes in lifestyle, medication or having a cardioverter defibrillator implanted.
Some countries offer mass screening, including Japan – where it is extended to the general school population – and the UK – where the charity Cardiac Risk in the Young subsidises screening of the heart’s structure and electrical systems for those aged between 14 and 35. In Italy, cardiac screening is mandatory for competitive athletes.
Australian cardiologists tend to support more targeted measures, citing the costs of mass screening and prevalence of “false positives” which could lead to anxiety, unnecessary follow-up testing and lifestyle restrictions.
After Alexandra’s death, it took the Thoms family nearly two years to navigate the complex process of identifying the genetic cause, getting family members tested and, finally, taking preventive measures for those at risk.
The testing revealed that Alexandra’s younger brother, Charlie, now 24, has the same advanced cardiomyopathy as his sister. He now has an implanted defibrillator and takes daily medication.
Gordon describes the process as “long, cumbersome and stressful”.
In Australia, referral systems for genetic testing through coroners, general practitioners and cardiologists are hit and miss, and victims’ families say symptoms can go unrecognised. Those who are referred to specialist clinics for genetic testing can face increasingly long wait times, and there is unequal access between metropolitan and regional areas and higher and lower socioeconomic groups, according to Jodie Ingles, the lab head and cardiac genetic counsellor at the Garvan Institute of Medical Research.
“The reality out there in the community is that it’s just a total mess,” Ingles says.
Alexandra always spoke with her hands. She felt her best with her long, brown hair straightened. It was “her uniform”, her friends say. She was funny. Excitable. She loved music, especially anything she could dance to.
“Out of everyone, it just wasn’t meant to be her – she was too full of life,” says her close friend Olivia Murdoch.
“When she died, she was thriving. That’s the thing with sudden cardiac death, there’s no visible illness; we were with her one weekend and then she was gone.”
When Gordon thinks about his daughter, he recalls skiing at her favourite spots at Mount Hotham in Victoria’s alpine region.
“She loved adventure and was totally fearless – she would push me to ski in places that I wouldn’t have gone on my own, always with a big smile on her face,” he says.
“My wife and I often talk about how she lived her life almost as if she knew tomorrow may never come.”
Jonathan Barrett is Guardian Australia’s business editor. His father died from a sudden cardiac arrest in 1998, aged 57. It was caused by an undetected genetic heart condition.