The Prime Minister's recent cardiovascular difficulties came as a shock partly because as he is so young and vigorous it is difficult to imagine Tony Blair as being anything but at the peak of fitness. Speculation naturally turns to whether the stress of the job could be a factor and he has the most difficult year of his career ? a career that had until now moved ever relentlessly upwards.

We know that heart rhythm disturbances like those suffered by the Prime Minister are very closely linked to emotional turmoil. This is probably secondary to a surge of a cascade of cardiac stimulant hormones like adrenaline which force the heart to beat faster in preparation for the fight or flight in the face of an enemy which our evolutionary history has prepared us for.

It is no accident that sudden cardiac death has long been linked anecdotally with strong emotion and there are many documented case series in the medical literature of individuals experiencing cardiac arrest or sudden death in settings of acute grief, fear or anger. We know sudden death increases in populations experiencing emotionally devastating disasters such as earthquake or war.

Medical research which closely monitors those vulnerable to heart rhythm disturbances finds that Monday is the most "popular" day for an abnormal rhythm probably because of the stress of returning to work after a relaxing week-end. It is interesting to note that the Prime Minister was admitted to hospital on Sunday ? perhaps a sign that the anticipated stress of the forthcoming week comes a bit earlier if you are running the country.

The most precise investigation of the link between emotional state and heart rhythm disturbances conducted by Rachel and Lampert and colleagues at Yale University in New Haven USA in 2002 where mood diaries were closely matched with electocardiogram monitoring. Of all the emotions recorded ? including anxiety, worry, sadness ? it was in fact the emotion of anger that was most frequently associated with the kind of heart rhythm disturbances experienced by the Prime Minister.

This intriguing result fits in with the medical view dating as far back as the 1950s that one key risk factor for cardiovascular disease is labouring under a Type A Personality. This Personality Type was characterised by competitiveness, excessive drive and an enhanced sense of time urgency. Basically, the Type A pattern refers to any person involved in an aggressive and incessant struggle to achieve more and more in less and less time. A Type A can be spotted because their aggression, competitiveness and impatience leads to muscle tension as well as an alert, and rapid speech style plus an accelerated pace of activities.

Does this ring any bells yet?

As they are so "goal directed" or to use the less technical term ? pushy ? Type As naturally also suffer from irritation, hostility and an increased potential for anger. This is because they eventually find most others around them are not travelling as fast as they are, and so are getting in the way. As a result there is huge frustration at not getting their expected results ? this leads to anger and adrenaline overload. Then you find yourself trying to rearrange your diary with your personal assistant as they jog along besides as you are stretchered to the hospital.

It is intriguing to note that Tony Blair, in true Type A fashion, was holding meetings the very next day after leaving hospital despite being warned by his doctors to rest.

But the problem with the Type A theory is that it proved difficult to measure reliably the Type A personality and define it precisely enough: everyone after all is a bit competitive from time to time, so when does this fall over into the danger of being a Type A?

Yet new research by a Canadian psychologist now promises to solve this problem from an unexpected direction that has surprising and ominous pertinence to Tony Blair.

Stewart McCann of University College of Cape Breton in Nova Scotia has recently found that the younger you are when you achieve greatness the shorter your eventual life span. There seems to be an intriguing link between precocious achievement and poorer long term physical health, and Tony Blair was the youngest British prime minister for almost two centuries. At the age of 43 he became the youngest prime minister since Lord Liverpool in 1812.

First, McCann looked at 22 different samples of high achievers like prime ministers, popes, supreme court justices, Nobel prize recipients, Oscar winners and signers of the US Declaration of Independence. In practically all of these groups he found that the younger you are when you achieve greatness, the shorter your eventual life. This puzzling finding, he suggests, is explained by the fact that young high achievers almost certainly are the most pushy and score highest on the Type A personality and this explains the link between fast success and a quick exit.

Most ominously for the Prime Minister, Dr McCann has now recently repeated his study focusing most specifically on politicians, in particular almost 2000 US governors. He also used special statistical techniques to eliminate the possibility that his first series of findings could be put down to some statistical artefact. McCann indeed found again that governors elected of office at younger ages tended to have shorter lives.

On average, former governors reached their posts at age 49, but age at election ranged from 23 to 81 years. The average age of death was age 70, but ranged from 32 to 103. Comparing age of election to age of death, McCann discovered that men elected governor at a relatively young age also tended to die at an earlier age.

But it's not just the ongoing stress of simply serving as governor which is shortening their lives, as the study took that into account with various measures of how much stress was experienced by each governor from their work.

Instead, it seems the crucial variable is how quickly you get success, which must be linked surely to having a pushy personality. Probably the true story is about the ominous interaction between a high stress job and a Type A personality.

But women, who often complain about the pushy men they have to contend with at work, should also beware as they are fast catching up with men in the heart disease stakes. The Type A personality it seems is not just a male preserve and McCann himself notes that a previous study of a small sample of women who have won an Academy Award for Best Supporting Actress suggested that early female achievers may also have a shorter lifespan.

Given most of us are unlikely to be bothered with the problems of winning an Academy Award or waving to an election night crowd on the steps of Downing Street, does this research have any relevance to us? Could the less than steroidal pushiness that we experience in our daily lives effect our hearts and life span? In fact the most "ordinary" group that McCann examined in his research were eminent psychologists, and yet the age at which they received their PhD also correlated with their length of life.

If it does seem to be the case that even relatively ordinary pushiness can lead to heart disease the key question becomes can you get Type A's to calm down and become more Zen-like and so get them to live longer. This is something many enemy nations worried about where the Prime Minister's boundless energy could take his attentions to next, like North Korea, are probably keen to know the answer to.

There is much evidence that getting Type A's to adopt the necessary life-style changes that require them to slow down and give up their goal directed behaviour is very difficult. However there is some evidence that getting them to take up moderate exercise does have a significant impact on reducing their cardiac vulnerability.

The problem is many Type A's take up exercise with the gusto that they bring to the rest of their lives (have you seen the way Tony Blair plays tennis?) and sudden death has also been linked in epidemiological studies to vigorous exercise, partly because exercise is also a potent releaser of cardiac stimulant chemicals like adrenaline.

The real problem though is that being a Type A is usually so highly rewarded in modern society that this makes it very difficult for doctors worried about their patients' health to discourage the behaviour.

For example, during the last three years a lady with the Type A personality has become a modern icon and role model to young people, particularly adolescent boys who are usually difficult to motivate. She is competitive, impatient, always alert and gets aggressive when frustrated. She tries to accomplish more and more in less and less time. Her name is Lara Croft.