Having a hot temper may increase your risk of having a heart attack or stroke, according to researchers.

Rage often precedes an attack and may be the trigger, say the US researchers who trawled medical literature.

They identified a dangerous period of about two hours following an outburst when people were at heightened risk.

But they say more work is needed to understand the link and find out if stress-busting strategies could avoid such complications.

People who have existing risk factors, such as a history of heart disease, are particularly susceptible, they told the European Heart Journal.

In the two hours immediately after an angry outburst, risk of a heart attack increased nearly five-fold and risk of stroke increased more than three-fold, the data from nine studies and involving thousands of people suggests.

The Harvard School of Public Health researchers say, at a population level, the risk with a single outburst of anger is relatively low - one extra heart attack per 10,000 people per year could be expected among people with low cardiovascular risk who were angry only once a month, increasing to an extra four per 10,000 people with a high cardiovascular risk.

But the risk is cumulative, meaning temper-prone individuals will be at higher risk still.

Five episodes of anger a day would result in around 158 extra heart attacks per 10,000 people with a low cardiovascular risk per year, increasing to about 657 extra heart attacks per 10,000 among those with a high cardiovascular risk, Dr Elizabeth Mostofsky and colleagues calculate.

Dr Mostofsky said: "Although the risk of experiencing an acute cardiovascular event with any single outburst of anger is relatively low, the risk can accumulate for people with frequent episodes of anger."

It's unclear why anger might be dangerous - the researchers point out that their results do not necessarily indicate that anger causes heart and circulatory problems.

Experts know that chronic stress can contribute to heart disease, partly because it can raise blood pressure but also because people may deal with stress in unhealthy ways - by smoking or drinking too much alcohol, for example.

The researchers say it is worth testing what protection stress-busting strategies, such as yoga, might offer.

Doireann Maddock, senior cardiac nurse at the British Heart Foundation, said: "It's not clear what causes this effect. It may be linked to the physiological changes that anger causes to our bodies, but more research is needed to explore the biology behind this.

"The way you cope with anger and stress is also important. Learning how to relax can help you move on from high-pressure situations. Many people find that physical activity can help to let off steam after a stressful day.

"If you think you are experiencing harmful levels of stress or frequent anger outbursts talk to your GP."