An illustration of a heartbeat is shown.
Research suggests that stress and anger may trigger built-up artery plaque to break off, causing a heart attack. (For Spectrum Health Beat)

Intense anger or heavy physical exertion may be triggers for a first heart attack in some people, new research suggests.

In the study of more than 12,000 people, both intense activity and intense emotions each seemed to double the odds of suffering a heart attack in the next hour. That risk rose about threefold when people were upset and exerted themselves at the same time.

The study is far from the first to suggest—and it does not prove—that bouts of anger or physical exertion can trigger a heart attack.

But, it’s larger than past studies, and more diverse—covering first-time heart attack patients in 52 countries, said Barry Jacobs, a spokesman for the American Heart Association who was not involved in the research.

“This confirms that blowing your top is not good—for other people, or for you,” Jacobs said.

Do the findings mean that everyone who gets angry will see a similar spike in their heart attack risk?

“Common sense says no,” said Jacobs, director of behavioral sciences at the Crozer-Keystone Family Medicine Residency Program in Springfield, Pennsylvania.

He pointed to the underlying biology of it all: Intense emotions or activity can drive up blood pressure and heart rate, and cause blood vessels to constrict. That, in turn, may cause any artery-clogging “plaques” to rupture and cut off blood flow to the heart—prompting a heart attack.

But a person would have to harbor those plaques in the first place, Jacobs said.

In the study, researchers asked the heart attack patients whether they had been angry or emotionally upset in the hour before their heart attack, or during the same hour the day before. They also asked about heavy physical exertion.

The study did not dig for details—such as the type of physical activity, or whether a person had an angry outburst or silently simmered.

“What we felt was important was to ask the same person about two different time periods,” said lead researcher Dr. Andrew Smyth, of the Population Health Research Center at McMaster University, in Canada.

On average, his team found, people were over two times more likely to suffer a heart attack in the hour after a bout of intense emotions or activity, versus the same hour a day before.

In all, almost 14 percent of study participants said they’d exerted themselves in the hour before their heart attack symptoms arose. A similar number said they’d been angry or upset.

Smyth said his team did look at other factors that affect heart attack risk—but none of them changed the risks linked to exertion and intense emotions. Physical exertion, for example, raised people’s heart attack risk whether they were normally sedentary or regularly exercised.

Still, the researchers said, people face “external triggers” like anger and exertion every day, without succumbing to a heart attack. So, it’s likely that those triggers come into play only when a person has artery-clogging plaques that are particularly vulnerable to rupturing.

The findings on heavy exertion do not negate the importance of regular exercise, Smyth said. It’s well known, he noted, that exercise has many long-term health benefits—including a reduced risk of heart disease.

But Smyth did advise avoiding “extremes”—physical and emotional.

“I do appreciate the difficulty in doing this,” he said. “There are times when exposure to extremes of either is unavoidable.”

However, people with risk factors for heart attack can limit heavy exertion when possible, and “employ strategies” to avoid extreme emotions, according to Smyth.

Jacobs agreed. He said he does not advocate “burying your emotions.” But, he added, “people can learn more appropriate ways of dealing with their emotions.”

Jacobs pointed to meditation, breathing and relaxation exercises, and anger and stress management programs as sources of help. He suggested people talk to their doctor about resources in their community, or go online to learn simple techniques, such as breathing practices.

The findings were published Oct. 11 in the journal Circulation.