The findings fit in with a body of research suggesting that hostile and domineering men and women are at risk of developing heart disease, the No. 1 killer in the USA.

"This kind of anger can be bad for the heart," says Redford Williams of Duke University, an expert on anger management. Williams and others have shown a link between anger and heart disease.

Researcher Tim Smith of the University of Utah and his colleagues brought 150 married couples into the lab and asked them to pick a subject that often triggered fights.

The list of risky subjects included in-laws, finances and household chores. Couples were told to discuss the topic for six minutes while the researchers videotaped the talk.

Some couples had calm discussions, but others had spats filled with hostile or domineering remarks. The most hostile couples probably have fights at home that are even more volatile, Smith says.

Researchers then watched the tapes and rated each comment for the degree of hostility or control.

All men and women also were given a CT scan that looked for deposits in the coronary arteries, the vessels that supply the heart with blood.

When those vessels are clogged, a clot can form and trigger a heart attack.

The team discovered that:

• Wives who made a lot of hostile remarks had double the level of clogged arteries as those who discussed matters in a less hostile way. And the clogs were even worse for women with husbands who returned the fire.

• Husbands who made lots of domineering statements or those with a wife who displayed such behavior had arteries that were 1½ times more clogged than husbands who were not in controlling relationships.

Smith, who presented the team's findings on Friday at the American Psychosomatic Society meeting in Denver, said men and women who were rated as hostile said things such as "You are so stupid." Those who were termed domineering made remarks such as "You need to try this my way."

Such remarks are thought to trigger a stress response, one that keeps blood pressure high long after the fight has stopped, Smith says. That stress response may damage the blood vessels in a process that leads to clogged arteries, he says.

Couples can learn to interact in a kinder way when discussing hot topics, Williams says.

Couples who stop and listen instead of immediately firing back a nasty barb might end up with a better relationship and a healthier heart, he says.