Only a heartbeat away from a long, healthy life
By Chris Zdeb, edmontonjournal.com
EDMONTON — Shawn and Shane Mamer don’t worry anymore that they’ll die if their hearts start skipping a beat. Because when it happens — and it will, says their cardiologist — a shock five to 12 seconds later will get their hearts beating properly again.
The 31-year-old identical twins, dental students from Saskatoon who inherited a deadly heart condition, had defibrillators implanted in their chests last week at the Royal Alexandra Hospital.
It’s one of the ways doctors are reducing the number of seemingly healthy and fit young men who suddenly drop dead, usually while playing an explosive competitive sport such as hockey or football.
A lot of people black out before they get the jolt of electricity from an implanted defibrillator, the shock of which is very painful, says Dr. Evan Lockwood, "but feeling a shock is a good thing because it’s a sign you’re still alive.”
The incidence of all sudden cardiac deaths is estimated to range from one in 50,000 to one in 200,000 people.
One of the most common reasons for these tragic deaths is an undiagnosed genetic heart condition.
Arrhythmogenic right ventricular cardiomyopathy is one such hereditary heart problem. It’s caused by a genetic mutation that progressively replaces healthy heart muscle with fat. This weakens the heart, which can lead to arrhythmia or an irregular heart beat, and heart failure causing blackouts and possibly death.
The Mamers were diagnosed with the condition after they started experiencing palpitations, often the first symptom.
An uncle, who was so robust they called him ‘Superman,’ died of the condition at 48 last August. It claimed one of their grandfathers at age 33.
Besides the brothers, a genetic screening of other family members found their parents, a sister, and several cousins also have the condition, which affects one in 2,000 to one in 5,000 people in the general population.
The children of a parent with the condition have a 50 per cent chance of inheriting it.
Men are seven times more likely to die from it than women. The average age of death is 41.
"It is likely in their lifetime (the Mamers) will have shocks that will save their lives when they otherwise would have passed away,” Lockwood says.
They will no longer be able to play any competitive sports because high activity or exertion increases the risk of arrhythmias and death.
The genetic mutation they have is prevalent in Newfoundland, where 15 unrelated families have been diagnosed with it, but has become more common in Alberta since young male Newfoundlanders began moving here to work in the oilsands, Lockwood says.
Doctors at the Royal Alex and the Mazankowski Heart Institute see a couple of oilpatch workers with the condition every month. Before the last economic boom, they saw a couple a year.
The Mamers are both dads whose young children will be screened by age 10, and have defibrillators surgically implanted by age 20, if required, Shawn says. The surgery takes about 90 minutes and patients usually go home the same day.
Thousands and thousands of people are still walking around today because of a greater awareness of sudden cardiac death syndrome and better genetic testing, treatment and prevention, Lockwood says.
The defibrillators are an insurance policy for them, but they do not prevent arrhythmia or heart failure which are treated with medication, he adds. Eventually, some require heart transplants.
The exact genetic combinations for many genetic cardiac conditions are still unknown, but the number of genes being identified increases every few years, Lockwood notes.
"Twenty years from now we might be able to manipulate genes and maybe do something as novel as a gene transplant, or switch off or switch on a gene, or do gene repair on kids at birth or in utero,” he says.