(Photography by Kevin Van Paassen)
The first time John Murray’s heart-rate monitor spiked during a particularly arduous climb while riding his bike two years ago, he shrugged it off.
A self-described workout fanatic, the now 68-year-old thought his heart could handle anything. But when his monitor began flashing a heart rate above 275 beats per minute for a second time less than two weeks later, John began to worry.
A visit to his family doctor led John to Sunnybrook’s Dr. Eugene Crystal, a cardiac electrophysiologist, who explained that John had an arrhythmia. While extremely common, arrhythmias mean some part of the heart’s electrical grid is malfunctioning, and as John was told by Dr. Crystal: “We don’t fool around with the heart.”
John says a part of him felt “betrayed” by the diagnosis. “I spent 50-plus years working out, thinking that it was buying me more time,” says the retired film and television producer, noting that his heart condition came without warning signs. Despite being otherwise healthy, John had what Dr. Crystal colloquially referred to as an “athlete’s heart,” likely related to decades of pushing his heart rate to maximum intensity for long periods of time without adequate rest.
“I thought I was strengthening my heart, and it turns out the way I was approaching [exercise] was actually making my heart weaker,” John says.
When given treatment options, John decided to stay away from medications and go straight for the fix. That meant Dr. Crystal, who established the Schulich Heart Program’s arrhythmia services at Sunnybrook, would track down the malfunctioning parts of John’s heart and burn them, in order to create individual sections of scar tissue that would block the stray electrical signals that were setting off his arrhythmia.
While the procedure, called a cardiac ablation, is traditionally performed using catheters, electrodes and X-rays to identify and isolate those sections, the advent of leading-edge technologies like three-dimensional mapping and robotics are changing how doctors at Sunnybrook perform cardiac ablations.
Sunnybrook is the first hospital in Canada and the only hospital in Ontario to use a powerful combination of robotics and 3D mapping during the procedures, which results in reduced exposure to potentially harmful radiation, greater precision during the procedure and fewer complications.
It’s a system Dr. Crystal compares to GPS and signal triangulation, methods used to pinpoint the location of a cellphone user.
“You move a wire around the heart and it records electrical points,” explains Dr. Benedict Glover, Dr. Crystal’s colleague and the incoming director of arrhythmia services at the Schulich Heart Program. “We can recreate the inside structure of one of the chambers of the heart within about 15 minutes and record about 20,000 electrical points.”
This method creates an extremely detailed, high-definition map that is “much more accurate than you would see in an X-ray,” Dr. Glover continues. “We can pinpoint short circuits within the heart and see where the problem is.”
The thin, flexible catheters used during the mapping process also include sensors that record how much force the doctors are applying to the tip of the wire. This means there’s less risk of perforation of heart tissue – a concern if you’re only relying on your fingers to gauge how close you are to the wall of the heart.
These tools make the ablations “absolutely safer,” Dr. Glover says.
As the heart’s electrical information is mapped by the diagnostic catheter, the heart’s pulses are displayed on a screen in a 3D model, allowing doctors to see any abnormalities. Then, another catheter with a specialized tip that emits heat is used to target the abnormal tissue and create tiny scars to block the electrical signals that cause the arrhythmia.
This surgery can be done manually or with the help of robotics. With robotics, electrophysiologists can manipulate the magnetic system to drive the wires around inside the heart while sitting in a separate room – away from possible radiation exposure and with millimetre precision.
“It’s very similar to video games. You’re operating in virtual reality; it’s a reconstruction built from imaging and from tracing equipment and from pieces of images from ultrasounds,” Dr. Crystal explains.
“It’s a reflection of reality, and the tools you use are joysticks, a mouse and the button.”
Going forward, Dr. Crystal, who is also the president of the Society for Cardiac Robotic Navigation (Americas), says there is the potential for cardiac ablations to be done remotely. In this scenario, a doctor in one location could guide robotic tools that are hundreds of kilometres away.
“These tools will [eventually] become much more widespread [and] be used for the procedures which we today do manually,” Dr. Crystal says. “They [can] become the tools for telemedicine for complex and difficult cases.”
In the end, John underwent two full cardiac ablations with Dr. Crystal, following an initial attempt to recalibrate his heart through a smaller procedure called an electrical cardioversion. His heart rhythm had stabilized following that first treatment, but reverted to abnormally high levels within days of John leaving the hospital. The same thing happened after John’s first ablation, leading Dr. Crystal to classify John’s heart as “stubborn” and prone to reversals. A second (and final) ablation did the trick.
While the ablations were John’s first major operations, he said he felt surprisingly calm as he was prepped for the procedure, in large part because of the attitude of the medical staff.
“Everybody around me was helping me deal with the stress,” John says. “I never felt alone.”
And as someone who worked in the entertainment industry his whole life, John says the fact that the operating room looked like a “very high-tech television studio” also helped put him at ease.
According to Dr. Glover, John isn’t the only patient who was comforted by the level of technology involved and the amount of information gathered before the procedure. Some even say the operating room “looks like something space age,” Dr. Glover says, noting he’s grateful Sunnybrook has supported an investment in technology that leads to better patient outcomes and a safer work environment.
Two years after his second ablation, John’s heart is humming along at regular levels. He’s back on his bike and working out at the gym – with a few modifications.
The information Dr. Crystal was able to gather about John’s heart had an unexpected side benefit for John: It has given him a whole new approach to fitness. He still makes time for three gym workouts each week and does up to 500 kilometres on his bike, but he engages in short bursts of high-intensity exercise that give his heart rest time to recover.
John is also part of a global study that Dr. Crystal is conducting that aims to further understand the relationship between arrhythmias and strokes, as well as how to prevent reversals from happening after ablations.
“I feel fitter today than I did when I was 20,” John says of his life since cardiac ablations. “I’m smarter about fitness and [have more] self-awareness. There’s a whole rhythm to things now.”