Prevention & Recovery
Could your child have a heart arrhythmia?
Prevention & Recovery
Could your child have a heart arrhythmia?
On a warm April night in 2008,16-year-old Taylor Allan was hanging out at a house party not far from her home in Kingston, Ont. The kids were in the backyard, hot-tubbing and jumping on the trampoline. Shortly before 11 p.m., Taylor, a Grade 11 student and star athlete, went to join her friends in the tub. She had less than an hour to live.
As she was about to climb in, Taylor complained of feeling dizzy to her friends. The next minute, she collapsed, never regaining consciousness. She was pronounced dead at a local hospital. "Her friends did everything they could for her with CPR, and paramedics worked on her, too," says Ken Allan, her grieving father. Taylor's heart had gone into a spasm and stopped beating – the result of an undetected genetic defect known as arrhythmogenic right ventricular cardiomyopathy (ARVC), which was later diagnosed on autopsy at the Hospital for Sick Children in Toronto.
ARVC is one of a cluster of inherited conditions that cause the heart to beat dangerously faster or slower than normal, or to fl utter helplessly in an uncontrolled manner known as fibrillation – sometimes leading to sudden death. Each year in Canada 35,000 to 40,000 people die of sudden cardiac death, and an undetermined percentage of them are due to inherited arrhythmias. This is especially true in younger individuals.
Ken believes his daughter may be alive today if there was wider recognition of the warning signs of such conditions, in both the general population and the medical community. Dr. Joel Kirsh, a pediatric cardiologist at the Hospital for Sick Children, agrees. "It's time for these treatable conditions to be at the front of physicians' minds, not at the back of a textbook," he says.
Taylor had been suffering episodes of faintness for some time. Rushed to the hospital after suddenly blacking out during a soccer match in April 2007, she had been discharged with a clean bill of health after routine tests, including an electrocardiogram (ECG) that showed no abnormalities. Ken says they were told that frequent fainting was a normal part of growing up for girls and not to worry since Taylor's tests had come back fine.
Until relatively recently, little was known about the prevalence and genetics of these difficult-to-diagnose arrhythmias. Conventional autopsies can miss them as an underlying cause of death, which might be registered simply as a sudden death, cardiac arrest or drowning. To boost awareness of these defects, Taylor's mother, Jackie Allan, has joined forces with concerned physicians and the Canadian SADS Foundation, a charity dedicated to supporting families affected by inherited cardiac rhythm abnormalities, as well as raising public awareness about these potentially life-threatening conditions.
Detected early enough, the silent killers can be managed with drugs such as beta-blockers, which prevent vulnerable hearts from going into a spasm as an overreaction to sudden stress, or with implanted cardioverter defibrillators. These devices can shock an irregular heartbeat back into a normal rhythm. For some patients, a transplant may eventually be necessary.
Page 1 of 4 -- Learn about another form of ARVC - Long Q-T syndrome - on page 2.
A young athlete dying unexpectedly tends to grab headlines, but a sudden cardiac death can happen to anyone, anywhere, any time – even at rest. In 1990, for example, Pam Husband's 16-year-old son, Greg, died in his bed. "His dad just found him lying there in the morning," says the mom from Mississauga, Ont.
At about age nine or 10, Greg started passing out at the sudden sound of his alarm clock going off, she says. Greg was originally diagnosed with a form of epilepsy. He had no cardiac testing until he was 14 and was about to go on medication for attention deficit disorder. "His family doctor did an ECG and the results were reported to be normal," says Pam. She adds that some time after Greg died, a reanalysis of the original ECG was done by an expert electrophysiologist-cardiologist, who said the ECG indicated that Greg had long Q-T syndrome, which occurs when an individual has a mutation in his ARVC gene. Long Q-T syndrome is a rare disorder of the heart's electrical system that can happen in otherwise healthy people. Its name comes from the way the heart's electrical activity is recorded during an electrocardiogram.
"At the time of Greg's death, the medical community couldn't give us any answers," says Pam, "because with long Q-T, the heart tissue looks normal on autopsy."
Greg's younger sister, who had also started to have fainting spells, has been diagnosed with the same inherited syndrome and is now doing well on medication. "The sad irony of this is that with diagnosis and treatment, people can go on to live pretty normal lives," says Pam, who, with a group of affected parents, founded the Canadian SADS Foundation in 1995.
The charity is currently working with concerned physicians on a longterm public education program to raise awareness in communities across Canada, and targeting youth sports organizations. The foundation is also trying to encourage doctors to conduct research that could determine if largescale questionnaires and ECGs can pick up enough cases in youths to justify screening costs.
Another goal is to make automated external defibrillators (portable devices that can detect an irregular heartbeat and deliver a shock to stun it back into a normal rhythm) widely available in schools, sports facilities and public buildings, and to train people to use them. "Since mandating automated external defibrillators in all schools in the early 2000s, the state of New York reports that 52 lives have been saved," says Blake Hurst, public access defibrillation program coordinator for Halton Region, west of Toronto.
"Fortunately, people are more proactive about these genetic conditions now," says Pam, pointing to new cardiac autopsy standards in Ontario that investigate unexplained sudden deaths in people ages two to 40. The chief coroner's guidelines, introduced in July 2008, require pathologists to assess the hearts of young sudden-death victims for elusive conditions, such as ARVC, and to store heart tissue for genetic testing, because other family members are often affected by the condition.
Other jurisdictions across Canada are expected to follow suit. "The B.C. coroner's office is in the process of developing similar guidelines," says Dr. Shubhayan Sanatani, an electrophysiologist at the Children's Heart Centre at the B.C. Children's Hospital in Vancouver.
Page 2 of 4 -- What it's like to live with an implanted defibrillator on page 3.
Testimony to the difficulty of detecting these arrhythmias is in a 2008 report by Sanatani on ARVC in two Vancouver boys, ages 14 and 15, in the journal Pediatric Cardiology. One had collapsed during a soccer game, and the other had recently lost his 40-year-old father to sudden death from ARVC. "Diagnosing these familial conditions is challenging, even with a heightened index of suspicion," says Sanatani, "since the results on tests can all appear normal. In both these boys, the diagnosis was suspected based on a single irregular heartbeat during exercise testing."
Like Greg's sister, Ginelle Johnston, 18, of Calgary, is one of the lucky ones. Ginelle, now in her first year of university, was diagnosed with long Q-T syndrome at age 12 after her 48-year-old father died suddenly while waterskiing. The athletic child was placed on a high-dose beta-blocker and later implanted with a cardioverter defibrillator. She has one of the identified genes for long Q-T and is suspected of having another one, which accounts for the severity of her condition (the arrhythmia occurs even when she's asleep).
"It felt like a stick of dynamite had exploded in my chest"
Ginelle's implanted defibrillator and medication allow her to maintain an athletic lifestyle, but they come with a price. "I was shocked by my defibrillator three times at a skating rink, and I collapsed after the third shock," she says. "It felt like a stick of dynamite had exploded in my chest." Others describe the phenomenon as like being kicked in the chest by a horse. And since the beta-blocker medication affects blood circulation, Ginelle says her hands and feet get cold quickly in winter, and when she jogs she sometimes feels dizzy.
Her mother and older brother have both undergone testing and, fortunately, both are free of the defect. But knowing that you've passed the gene on to your child, especially one who has died, can be a terrible burden for a parent.
Clinicians stress the importance of testing the family members of all affected patients. According to Kirsh, if doctors identify a disorder in one person who dies, the odds are that several relatives will also have it. A case in point is the family of Perry Cook of Wareham, Nfld., who have the ARVC gene. His younger brother passed away suddenly at age 27 of now-suspected ARVC, and both his children have tested positive for an ARVC gene. His son Dillon, now 16, was diagnosed and implanted with a defibrillator at age 13.
"We've made huge strides since the 1980s in our ability to detect and treat these elusive disorders," says Kirsh. He concedes that it costs money to test a patient, but says the $5,000 spent on testing to save 50 or 60 years of life for a young person is "not much, considering the amounts spent on kidney dialysis and coronary bypass surgery for older people."
In northern Italy, a screening program for older children and young adults about to enter organized sports leagues has markedly reduced sudden deaths. Screening programs in Nevada have picked up at-risk high school athletes. And, in Japan, all kids going into junior high and high school are screened. But, to date, no such programs have been launched in Canada.
Page 3 of 4 -- On page 4, find out how genetic links are helping scientists looking for a cure.
Dampening the enthusiasm for screening is the thorny issue of who would read the large volume of ECGs. "If you're a cardiologist who is expert in long Q-T syndrome, you'll pick this up more reliably on an ECG than a general cardiologist or a family doctor," says Dr. Robert Hamilton, a pediatric cardiologist at Sick Kids. There are also the social and financial costs of false positives – readings that suggest nonexistent abnormalities. "These cause people psychological distress and require more resources for further medical testing," says Kirsh. And what's the best time to screen? In infancy? Just before or just after puberty, when symptoms of these conditions often begin to manifest themselves? The answers to such questions must be considered by any screening strategy.
Scientists are homing in on the lethal genes. In St. John's, Nfld., researchers at Memorial University, led by molecular geneticist Dr. Terry-Lynn Young, are studying 16 large extended kinships encompassing some 1,200 people – all thought to be genetically linked to a common 18th-century ancestor. Their family bibles are full of the names of people who, over the generations, died inexplicably at a young age. The culprit is now thought to be ARVC. "The youngest victim we've studied was a man of 19, who died eight years ago, and the youngest person undergoing treatment is a 13-year-old boy," says geneticist Kathleen Hodgkinson, who specializes in genetic counselling.
Deborah Roberts belongs to one of these extended families. "We'd all meet at the funeral of some 19-year-old relative who just dropped dead and whisper about the family curse," says Deborah, who grew up in Mount Pearl, Nfld. The 46-year-old mother of a son with ARVC was herself diagnosed with the abnormality after a blood test and a heart biopsy in 1997. She was later implanted with a defibrillator.
Two of Deborah's sons have normal hearts, but her middle son, Adam, was diagnosed with ARVC at age 15 and implanted with a defibrillator. Now 21, he's thinking about his future as a parent. "We want to stamp out this defect in this generation," says Deborah. "My son is talking about having in vitro fertilization and genetic embryo testing with his future wife so the defect won't be passed on to their children."
Although conventional CPR training is now mandatory for all high school students in Alberta, Manitoba and Ontario, experts support the placement of automated external defibrillators in schools and the training of students in their use. "If we're going to give teenagers vaccines to protect against sexually transmitted diseases and teach them how to avoid pregnancy," says Kirsh, "then we can take the three to five hours needed to teach them how to save someone's life."
Warning signs and risk factors
You and your family should be tested for an inherited heart arrhythmia if you have any of the following:
• A family history of sudden death in young, healthy relatives (i.e., under age 40). For example, a drowning of a strong swimmer in a backyard pool or a death involving a single-car accident with no evidence of external cause, such as skidding or driver impairment
• Episodes of fainting or seizures during or directly after exercise, at times of acute excitement or emotional distress, or after hearing a loud noise, such as an alarm clock
• Consistent or unusual chest pain and/or shortness of breath during exercise
• A frequently racing heart rate or palpitations
For information about training in cardiac resuscitation, contact:
• ACT Foundation, www.actfoundation.ca
• Canadian Red Cross, www.redcross.ca
• Heart and Stroke Foundation of Canada, www.heartandstroke.ca
• St. John Ambulance, www.sja.ca
You can also phone your local office of any of the above.