Last updated: Apr 11, 2008
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Stress, anger, even overeating can trigger a heart attack.
(ROYALTY-FREE/CORBIS/VEER)
Roughly half of all people who have a heart attack blame an event—such as a fight with their boss or heavy exercise. Reality is more complicated.

"Heart attack patients had an underlying condition that caused the attack," says Sharonne Hayes, MD, director of the Mayo Clinic's Women's Heart Clinic. "The snow shoveling or the anger just unmasked the condition."

Surprising, silent causes of heart attacks
Heart attacks occur when a piece of plaque lining an artery wall ruptures and blocks the flow of blood to the heart. A trigger might contribute to that rupture, but the heart attack was probably inevitable—unless the person was receiving preventive treatment.

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That lesson became clear to Kevin Ambrose, 52, of Washington Grove, Md., who had his second heart attack 90 minutes after having sex with his wife. Tests showed that Ambrose had a massive blockage in his neck arteries, which also increased his risk for stroke. Within a week he was on the operating table getting a stent implanted.

Triggers to watch out for
For people at risk for a heart attack, stress and anger are common triggers, especially within two hours after the outburst. Stress hormones cause blood vessels to constrict and slow blood flow to the heart. Taking aspirin can mitigate this effect.

Gluttony may be another risk factor. In a study of 2,000 heart attack survivors, researchers found that more than 150 reported eating a heavy meal up to 26 hours before the attack. Of those patients, a significant number ate that meal in the two hours leading up to the attack. One explanation is that eating raises levels of the hormone norepinephrine, which can spike blood pressure and heart rate.

"Overeating should be considered a heart attack trigger, much in the same way that extreme physical activities and severe anger episodes may cause an MI (myocardial infarction)," the lead researcher, Francisco Lopez-Jimenez, MD, now a cardiologist at the Mayo Clinic, has said.

Exercise and heart attack
Compared with women, studies show that men are up to 19 times more likely to have a heart attack following a heavy workout than during other times of day.

That increase sounds scary, but the odds that a man will have a heart attack after any particular round of exercise are still low. And the more often he works out, the less likely it is that exercise will ever set off an attack.

Men and women who try to make up for months of inactivity with a session of intense exercise are at greater risk for sudden heart attack than those who exercise on a regular basis.