Many things can speed up a person’s heartbeat, including a sudden fright or drinking too much caffeine.
But having a fast heart rate all the time could be a predictor of premature death in people with underlying cardiovascular disease, researchers suggest.
In an analysis of data collected from more than 31,000 participants of two international studies, researchers found that people with the most rapid heart rate — more than 78 beats per minute — had an elevated risk of dying from a heart attack, stroke or heart failure.
“The study contributes to an already very large body of evidence that increased heart rate is associated with increased risk for cardiovascular events,” lead author Dr. Eva Lonn, a professor of medicine at McMaster University in Hamilton, said Tuesday.
Compared to study participants with the lowest heart rate — 58 beats per minute or less — those whose hearts pumped beyond 78 beats had a 39 per cent increased risk of having a heart attack or other major cardiovascular event, a 77 per cent higher risk of dying from such an event and a 65 per cent increased risk of death from any cause.
Lonn said subjects whose resting rate topped 78 beats per minute were also more than twice as likely to be hospitalized for heart failure compared to subjects with the slowest heartbeat.
To conduct the study, Lonn’s team analyzed masses of data from the ONTARGET and TRANSCEND trials, which were undertaken to see whether medications could reduce heart attacks, strokes and heart failure in patients with stable cardiovascular disease or diabetes with organ damage.
Those trials, led by McMaster’s Dr. Salim Yusuf, followed 31,531 patients aged 55 and older for almost five years.
As part of the study, participants had their resting heart rate measured on a regular basis, along with other tests, said Lonn, whose study results were presented at the Canadian Cardiovascular Congress in Montreal.
Dr. Marco Di Buono, director of research for the Heart and Stroke Foundation of Ontario, said the study findings are important because they point to “a pretty strong indicator that’s very easy to measure.”
“So it’s as simple as going to your doctor’s office and them taking your resting heart rate,” he said Tuesday from Montreal. “It’s not something that’s going to be labour-intensive or resource-intensive.”
“And it can be pretty indicative of basically life-expectancy or future cardiovascular risk.”
While it’s not known definitively why a persistently speeded-up heartbeat can lead to heart attacks and other life-threatening events, there are a number of theories, said Di Buono. A high heart rate may end up fatiguing the heart muscle over time, leading to the organ’s inability to pump properly, a condition known as heart failure.
A rapid heartbeat may also increase pressure in the blood vessels, allowing blood clots to form and causing a heart attack, he hypothesized.
What is known is that lack of exercise, tobacco use and poor diet — one high in fat and sodium, low in fibre and fruit and vegetables — can result in an accelerated heart rate, he said, noting that highly fit athletes typically have extremely low resting heart rates.
Lonn said for some people, medications along with lifestyle interventions may be needed to slow the heart.
“If a patient already had a heart attack or something else and is at risk for future events, then it may be useful to discuss it with the doctor and to see in addition to everything else — blood pressure, cholesterol, smoking — whether anything needs to be done besides,” she said.
“If it’s somebody who is otherwise healthy, I wouldn’t tell them they have to take a medication. I would tell them to review what’s not optimum in their lifestyle, to take a daily walk or another form of exercise, (to see) if they’re really bothered by something that causes them to be stressed out.”
Di Buono said the important message for the average Canadian is to focus on making lifestyle choices that will keep the heart pumping at a relatively slow, steady pace to improve long-term cardiovascular health.
“So healthy eating, stopping smoking and leading an active lifestyle — that’s really the best thing that anyone can do.”