On Mother’s Day 2013, Joe Bladek went on an after-dinner walk around his neighbourhood in Orillia, Ontario. Strolling with his wife Melissa Bladek, their eight-month-old son and Melissa’s mother, he took a step forward, into the middle of the street, and landed face-first on the pavement. For a second Melissa thought he’d tripped—but then she heard the loud thud of him hitting the pavement. “It was awful,” she says. “He hit the ground really hard.”

What came next lasted only a few minutes, but felt like a lifetime. Joe was thirty-two and otherwise healthy. Melissa wracked her brain to imagine what was wrong. Joe had spent the day barbequing with his family, sitting out on the back veranda with a drink, seemingly fine. When Melissa’s mom proposed the walk, he’d first tried to beg off, saying he was tired. “That was the only thing, in retrospect,” Melissa says, “that maybe should’ve tipped me off.”

Joe was convulsing and foaming at the mouth. Thinking it was a seizure, Melissa and her mother turned him on his side. They searched for his pulse, and Melissa struggled to dial 911 on her new iPhone, unable to see the number pad through her panic. An older couple, gardening in their yard nearby, used their cordless phone to make the call.

When firefighters arrived, they jumped out of the truck to perform CPR and use the defibrillation paddles. Joe’s chest flew up violently with each shock. Melissa remembers standing on the curb, screaming, “Oh Jesus, don’t let him die.”

Then the firefighters called out: they’d found his pulse. A few hours later, at Toronto General Hospital, doctors confirmed what Melissa had suspected when she saw the paddles put to her husband’s chest: Joe had suffered a cardiac arrest as a result of a complex heart condition he’d been born with.

Joe coming perilously close to death at thirty-two was hard for the Bladeks to accept, but in a strange, complicated way. Joe always knew he’d lived into his thirties because incredible medical advances had saved his life as a child. Now, nearly three decades later, it turned out he’d needed a heart doctor more than ever—but he’d lost touch with the medical system, and there was no one around to warn him that something was deeply wrong.

If you met Joe Bladek, you’d never know he had a heart condition. Now thirty-seven, he is tall and physically fit, full of energy, a mortgage broker who rarely gets sick. But he was born with something called Tetralogy of Fallot, a complex heart condition that combines four separate heart defects. For Joe, the condition required two surgeries, the first when he was eleven months old and the second when he was five years old.

Patients with Tetralogy of Fallot sometimes need a heart valve replacement in adulthood, too. But at the time he went into cardiac arrest, Joe wasn’t even being monitored—he hadn’t been seen by a cardiac specialist for two years. While he regularly saw a paediatric cardiologist as a child, that stopped when he turned eighteen. Moving around for school and work, he struggled to schedule appointments with his childhood specialist, though he should have been seen annually. Though he was technically still a patient, he was at the bottom of the cardiologist’s list. At Joe’s last appointment, two years before his cardiac arrest, his doctor had told him his valve didn’t yet need to be replaced.

Joe hadn’t spotted the signs that his heart was worsening. He brushed off episodes of fainting, dizzy spells and a racing heart—he’d experienced those as a child and teenager, and thought they were just a normal part of his condition. But then he’d collapsed.

Joe was lucky: the length of time he was unconscious while he arrested, he later learned, brought him precipitously close to having lasting brain damage. Doctors warned Melissa that when he came out of sedation, he might not remember her, or himself. When he did, “I wept for like fifteen minutes,” Melissa recalls. Though Joe’s long-term memory was unaffected, he did suffer some serious short-term memory issues for a while.

A certain bittersweetness is built into life for many people like Joe. In the late 1960s, children with congenital heart defects (CHDs) couldn’t expect to reach adulthood—their survival rates past childhood were around 20 percent. But in the following decades, medical innovations changed everything. One 2010 study covering 1987 to 2005 found that mortality rates in Canadian children with congenital heart defects decreased by 59 percent over that period, and by 67 percent for children with the most severe heart defects. Overall, new surgery techniques and medical advances saved hundreds of thousands of Canadian children.

One of those thousands was Bladek. And one of them was me—though, fortunately for me, my condition is less complex. The growing number of people like us living to adulthood is an incredible triumph of medicine. But it has also created a new problem. As of 2014, out of more than a quarter of a million people in Canada with congenital heart defects, two-thirds were adults. That number will keep growing, especially as paediatric cardiac surgery advances and as doctors save children with increasingly complex defects. The medical system, however, isn’t ready for these adult patients. Adult cardiology specialists have traditionally dealt only with acquired heart diseases, and those who train them didn’t anticipate the size of the new patient base heading their way. Experts agree that about half of adults with CHDs—those with more serious conditions—should be monitored throughout their life. But as of 2007, more than three-quarters of Canadian adults born with CHDs were not being followed by someone who had the expertise to monitor their hearts.

The consequences are often disastrous. “Every month a patient is showing up in the emergency room who has been lost to follow-up for years or sometimes decades,” says Dr. Erwin Oechslin, the medical director of the Toronto Congenital Cardiac Centre for Adults (TCCCA). “And some of these patients are in a life-threatening condition.” In fact, about twenty years ago, a study from five Canadian experts in adult congenital cardiology, including Oechslin, found that adults with congenital heart defects were more likely to die from them than from non-cardiac causes. More recent statistics aren’t available.

But a lack of doctors isn’t the only reason for these tragedies. Even if everyone had an excellent specialist, experts admit that there’s still a lot about these patients that they don’t know, and will only discover as they age. Many of the patients in the older cohorts—those in their mid-fifties and older—were saved in childhood by relatively new procedures. In adulthood, they’re helping to set the standards again. So are people Joe’s age, and younger.

Doctors told Joe as much, saying he was in one of the first generations living well into adulthood and physicians didn’t always know what to expect. “I’m really grateful that he’s here and he’s okay,” says Melissa. Now seen every year and a half by a cardiologist, Joe says his status as a test case is a mixed blessing. “I’m thankful that we have doctors that are willing to try new things,” he says, “but it also makes me feel frustrated that it’s not as cut and dry as ‘You have this, and now we do this.’”

In November 1944, a fifteen-month-old infant named Eileen Saxon was wheeled into surgery at Johns Hopkins Hospital in Baltimore. She’d been born with Tetralogy of Fallot, then known as “blue baby syndrome”—the heart defect caused blood to shunt past her lungs, creating oxygen deprivation and a faint blue pallor. Cardiac surgeon Alfred Blalock performed a procedure that connected two of the baby’s arteries together, increasing the blood flow to her lungs. Standing on a step stool by Blalock’s shoulder, coaching him through the process, was his medical technician Vivien Thomas, who’d spent the two previous years perfecting the procedure on two hundred dogs during experimental surgical work. When the two were approached by paediatric cardiologist Helen Taussig, they realized they could use it to save children’s lives.

The surgery wasn’t perfect; it only prolonged Saxon’s life by a period of months. But Blalock and Thomas’s second and third attempts, on an eleven-year-old girl and six-year-old boy, were complete successes. In 1945, the Journal of the American Medical Association published an article on the procedure, which became known as the Blalock-Taussig shunt. Due to the racism of the time—Thomas was Black—and his lack of formal medical training, the technician was given no credit. Within a year, more than two hundred patients underwent the shunt procedure at Hopkins. It was adopted worldwide for use on Tetralogy of Fallot patients and is still used to this day. It’s just one of the more famous advances in paediatric cardiac surgery that have allowed children with a wide range of congenital defects to survive to adulthood.

I was born in 1992, well after many of those transformative advances took place, with a complete atrioventricular septal defect. Two holes, one between the top two chambers and one between the bottom two, effectively combined into one large hole in the middle of my heart. As a result, both my heart and lungs needed to work harder to pump oxygenated blood through my body. I also have abnormalities that cause one of my heart valves to leak. I was diagnosed when I was five and had surgery within months to repair the holes.

As an adult, my condition doesn’t feel like a big part of my life. Every two years I see my paediatric cardiologist, Dr. Norman Musewe, to monitor my heart valve—it still leaks a little, but it’s unlikely I’ll need surgery to replace it. I still go to Musewe’s Markham, Ontario, office because when, at twenty, I asked why I hadn’t been transferred, he told me he couldn’t find any community adult cardiologists who knew enough about CHDs to take his older patients. Instead of leaving us in the lurch, Musewe resolved to keep seeing us.

The older I’ve gotten, the more I feel comically out of place in his waiting room. There are a set of toys in the corner that I played with when I was a child, and each time I come to my appointment, getting further into adulthood, I sit and watch toddlers and young children play with them instead.

I’ve also realized, though, just how lucky I am. Very few paediatric specialists in Canada do what Musewe does. And once someone leaves the system, it isn’t necessarily an easy road back. Getting an appropriate referral is a gamble. Expertise is concentrated in big cities, which makes it more difficult for patients in small towns or northern communities to access care; adult congenital heart disease (ACHD) services are wholly unavailable in Prince Edward Island and New Brunswick, along with all three territories. Most of the fifteen Canadian clinics serving ACHD patients have months-long waitlists, though they do make exceptions for people who come to them in emergency circumstances.

The Toronto Congenital Cardiac Centre for Adults, located downtown in the Toronto General Hospital, sees the lion’s share of patients. It actively follows about 9,500 patients and takes in somewhere between six hundred and seven hundred patients per year. Founded in 1959, it is the first and largest ACHD program in the world. Most of the other fourteen Canadian centres were opened in the 1980s and 1990s.

In the last ten years, the TCCCA has doubled its number of patients, Oechslin says. He expects in the next decade that number will double again. With a four-month waitlist for referrals, Oechslin told me in late October that he needed new cardiologists and surgeons. When we spoke again a few months later, the centre had managed to hire two new cardiologists—both from London, England. That they had to look so far afield, Oechslin says, speaks to the lack of physicians who are trained in the specialty in Canada.

The statistics on physician training confirm that things are dismal. According to a 2012 Canada-wide study, less than 2 percent of all Canadian adult cardiologists had formal training in ACHD. Of the eighty adult and paediatric cardiologists in Canada who were affiliated with an adult clinic at the time of the study, just over a quarter of them had received formal training. Perhaps more surprisingly, twelve of the twenty surgeons who operated on adult patients in Canada were paediatric cardiac surgeons, and many of the cardiologists were trained as paediatric surgeons.

While healthy child and adult hearts don’t differ much anatomically—an adult’s is naturally larger, and its average resting and active heart rates are slightly different than a child’s—physicians and surgeons working with ACHD patients need to have an understanding of adult diseases, like coronary artery disease, hypertension and diabetes, on top of their knowledge of congenital defects. “As people’s hearts get older they start developing other types of heart disease not seen in paediatrics,” says Dr. Marla Kiess, the director of the Pacific Adult Congenital Heart Clinic in Vancouver. “You need to have training in adult disease in order to look after adults. It’s just not appropriate as a paediatric person without specific training to be looking after adult patients.”

It’s not just the specialized clinics competing for trained physicians. My doctor, Musewe, is looking for a paediatric cardiologist with interest or training in ACHD to join his practice, and it’s nearly impossible, he says. (When I asked him how long he’d been looking, he jokingly asked me: “Why? Do you know somebody?”)

How did this happen? When it comes to training adult cardiologists, it’s about supply and demand in the population. For a long time, the demand for trained ACHD specialists just wasn’t there. Among adult patients, people with acquired heart conditions have always outnumbered those with congenital conditions by a wide margin. “Even though the number of patients with adult congenital heart disease is in fact increasing, it’s still tiny compared to the people with acquired heart disease,” says Dr. Henry Kafka, an adult cardiologist based in Belleville, Ontario. But, he adds, “that is changing.”

The problem with waiting for demand to spark new training programs is that medical school takes many years, especially when you add on specializations. The Royal College of Physicians and Surgeons of Canada is now updating its curriculum for adult cardiology residents, moving away from an outdated model of time-based “blocks” of specialization that only require one month of paediatric cardiology training and one month of training in congenital defects. Those blocks may be delivered differently depending on which university a resident attends. “Some centres have done pure paediatric cardiology, others have done two adult congenital months and try to insert some paediatrics in it,” says Alison Montgomery, the chair for the Royal College’s Specialty Committee in Cardiology, which is responsible for advising the college on what cardiology residents should be learning and for accrediting university cardiology programs.

The new program, Montgomery says, will focus more on the end result by setting specific milestones the residents must meet, and competencies they’ll be evaluated on, including some involving adult congenital heart disease. Montgomery expects the new program to go into effect in 2020 or 2021. That means there will be a bigger new cohort of specialists by about 2028.

The historical lack of training for adult specialists has also left its mark elsewhere: cardiologists operating private practices don’t always know how to treat adult patients with congenital defects. Even more dangerously, they may not know how much they don’t know.

Shelagh Ross is living proof of that. Ross, who has Tetralogy of Fallot, had always been conscientious about her heart condition. On paper, she did everything right. When she moved from Toronto to Halifax for university, she got a referral to the ACHD clinic there. But when she moved back, she wasn’t properly referred to the Toronto clinic, and was left to her own devices. She asked her general practitioner for a referral, and got sent to the chief cardiologist at Women’s College Hospital.

She checked in with him for years and was told her heart was fine. But one morning when Ross was thirty-three, she woke up with ventricular tachycardia, a fast heart rate caused by problematic electrical activity in the heart’s ventricles. “It was really awful. I got rushed to the hospital,” says Ross. Doctors performed a cardioversion on her, sending electric shocks to her heart to slow it down. “I was there for three weeks and that summer I had valve surgery. Apparently my valve was really leaky and my heart was really enlarged,” she says. From there, Ross was connected to the TCCCA.

“The cardiologist who was seeing me over the years didn’t really know what to look for,” Ross says. “Luckily, I survived.” It really did feel like a stroke of luck—Ross had been planning to go on a remote camping trip that weekend. Now fifty-six, Ross says the experience left her disappointed that her cardiologist hadn’t passed her on to the right people. “But maybe he didn’t know,” she says.

Falling out of medical care is partly a personal problem. It’s easy for young adult patients to stop attending appointments when they move away for school and feel healthy. I could see it happening to me—but my mother would’ve dragged me by the ear if I’d tried to miss one. For others, skipping out is part of a larger desire to feel like everyone else. “They’ve been patients from the moment they were born. They’ve been to clinics, they’ve been to the hospital,” says Kafka. “People get sick of being sick.”

Historically, too, the healthcare system has made it easy for people to disappear; the transition process wasn’t formalized, and patients depended entirely on doctors’ knowledge of where to send them. For decades, the only proper place to refer them was Toronto.

And some patients in the community may be in the same place Ross was, lulled into a false sense of security. If their cardiologist didn’t know to send them on to one of the centres for a consultation—which, with less than 4 percent of Canadian adult cardiologists affiliated with a centre, is a strong possibility—the patient would still be at risk of deteriorating. Such people have inadvertently left the system without even realizing it.

Ross went on to co-found the patient advocacy group Canadian Congenital Heart Alliance (CCHA) in 2004. Now in its fourteenth year, the group has 215 members, a collection of patients and family members. Its members do some advocacy work, and host events for patients, including an annual retreat. Ross, who has since stepped down as executive director and president, speculates that many of them come to the CCHA after coming too close to losing their lives. “I figured if I had done everything I could to look after myself and that still happened,” says Ross, “then I’m sure that was happening to a whole bunch of other people.”

Over the course of reporting this story, I discovered I was wrong when I thought my condition had always been a simple one. In reality, it took years to be sure it wouldn’t kill me. When I was three, my mom tells me,I keeled over in the bathtub; my heart had stopped beating. Mom grabbed me out of the tub and, sobbing, violently shook me until I came to. Two years later, when she told Sick Kids cardiologists about the incident, she says they told her that I’d likely experienced heart failure, and shaking me had brought me back to life.

But before we got to Sick Kids, a paediatrician referred me to Musewe. And when he checked my heart, my mom remembers seeing him start to cry—I’d been diagnosed so late that my condition had worsened dramatically. If I lay down, a bump in my chest was visible because my heart was so enlarged.

My mother remembers Musewe telling her that there was a chance I would need a heart and lung transplant. Even after I went through surgery to repair the leaky valves, I was expected to be on medication for the rest of my life, but that life wasn’t supposed to last long. “They said to us, ‘Even after the repair, Kelsey may live to about eleven, but we don’t know,’” Mom recalls. They told my parents that medicine and technology changes, so they couldn’t say for sure. In the hospital wing where I stayed after the operation, several children—including one I shared a room with—died. “They lost a lot of kids,” she says. “It was a totally different time.”

It’s human nature to apply the science of the current moment retrospectively—to see close calls, terrifying at the time, through the rosy lens of what we know now. But doing that also means forgetting the opposite thing: the fact that thousands of people across Canada are operating according to the prognoses of their childhoods. They never got an update.

“Twenty to thirty years ago, when these patients graduated from paediatric cardiology, the paediatric cardiologists told them ‘You’re doing great,’ and what the patients and the parents heard was, ‘I’m doing great, I’m fixed, I’m cured,’” says Oechslin. “Then these young people, they don’t follow up... until they run into problems.” Coupled with the fact that transition was then considered the responsibility of the patient, and not the hospital, many ACHD patients fell through the cracks.

Aubyn Baker, fıfty-four, is just one of many patients like this. Baker was born with a bicuspid valve, as well as a coarctation of the aorta which was repaired in childhood. When she turned eighteen in the early 1980s, she left the Children’s Hospital of Eastern Ontario thinking the coarctation had been permanently resolved. “There was no ‘You should be seen by an adult cardiologist,’ there was none of that,” Baker says. Only when she was thirty-nine and began to experience extreme lethargy—getting winded walking her garbage can to the curb—did she realize her condition was life-long and sought out an adult centre.

No one can track what happens to patients like Baker who slip away from medical care. One of the only clues came from the 2000 study authored by Oeschslin and four other experts that determined that sudden death, progressive heart failure and surgery-related death were the most common causes of death for adults with congenital heart defects, beating out non-cardiac causes. But, like many studies about ACHD patients, this study is now nearly twenty years old; it may no longer be accurate.

Everyone—including me—who appears in this piece is one of the lucky ones. There are adults all across Canada who don’t know their hearts are ticking time bombs. But since so many of them aren’t attached to clinics, doctors don’t know how many there are. Jennifer Lapum, a Ryerson University nursing professor who studies the issue, says when she spoke to physicians, “they [were] not exactly sure how many people are living with adult congenital heart disease.”

When I said I thought my condition was simple, I was mostly right—today, it isn’t considered complex. That for years I thought that was always the case is a good indication of how much better doctors now understand congenital heart defects. But it’s not a perfect understanding, and incredible progress can mask the struggle it has been, and still is, to keep patients like us alive. “We’re still guinea pigs,” Ross tells me. “You are, too.”

It’s encouraging that knowledge about ACHD patients is spreading across the country, inside and outside of medical schools. In addition to revamping its program for cardiology residents this year, the Royal College is working with experienced congenital cardiologists to develop a new diploma in treating ACHD. To help educate other cardiologists, the TCCCA started an annual ACHD education day in 2016. Oechslin said around seventy physicians per year come to the sessions.

Both the Pacific Adult Congenital Heart Clinic in Vancouver and the Toronto Congenital Cardiac Centre for Adults are developing services to reach outside their cities. Vancouver plans to regularly send a doctor, nurse and echocardiogram technician to northern communities, and they have affiliated cardiologists scattered elsewhere in British Columbia. Toronto is developing a similar model in Thunder Bay, where an ACHD cardiologist has already been hired;  northern Ontario patients will only need to make their way to Toronto if they need special tests or surgery.

Across the country, transition programs between children’s hospitals and adult clinics are being formalized and fine-tuned. British Columbia, which was the first province to develop a transition program for children with cardiac problems, recently rolled out a new plan with resources for community cardiologists as they decide where to refer patients. In Newfoundland, an adult cardiologist hosts twice-monthly ACHD clinics at Memorial University’s paediatric cardiology department—which means that for the majority of the clinic’s 150 adult patients, no transition is necessary. the TCCCA has created a clinical coordinator role to help higher-risk patients, like those with developmental disabilities, who may be vulnerable to disappearing from the system. For thousands of people of a certain generation, these changes have come just in the nick of time—or not.

Joe Bladek was unconscious for ten days after his cardiac arrest; he was sedated and covered in ice bags to allow his body, and his brain, to heal. He spent two months in the hospital to recuperate and have his valve replacement surgery before returning home. Since his surgery, he hasn’t experienced any of the fainting, dizziness and arrhythmia that he’d been used to. “As much as it was a challenging year,” he says, “it changed my life so much for the better.”

It’s hard to imagine the stress of being the first, of coming up into a system that isn’t prepared for you—a system that is still trying to determine what your quality of life will be like into middle and old age. Truthfully, I can’t imagine it. Despite being a twenty-six-year-old with a paediatric cardiologist—and despite learning that the world’s predictions for my life expectancy have drastically changed over the course of my living it—I’ve never felt like a test case. I knew, early on, that my condition would require lifelong attention, and I’ve been lucky enough to never leave the care of a cardiologist. I became an adult eleven years after Bladek, and nearly thirty years after Baker and Ross. Those years, it turned out, made all the difference.

An earlier version of this piece stated that Shelagh Ross was fifty-three. She is fifty-six. Maisonneuve regrets the error.