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By Jerome Burne, Times Online | timesonline.co.uk | April 26, 2004

Encouraging positive emotions has significant health benefits, a new study shows

It has long been recognised that positive emotions are linked with living longer and negative ones with a poorer outcome.

What has not been so clear is why: only last week, for instance, the journal Heart carried a study reporting that the risk of heart-attack survivors having a further attack is halved if they are loved and have friends. However, the researchers were puzzled as to the explanation and suggested that it might be because friends and family help them to stick to their treatment.

A much more plausible solution has been recently provided by a group of heart patients who were subjected to what some might consider a cruel and unusual regimen. Each was given a portable electrocardiogram machine that constantly monitored their hearts as they went about their daily business. Then, every 20 minutes during the day, it sounded a buzzer, which meant that they had to drop everything and make a note of what they were doing and how they were feeling.

The results showed that there was a direct and immediate link between the emotions that patients were feeling at any one moment and the state of their hearts.

We found that during times of mental stress and negative emotions their hearts showed a reduced capacity to respond, says Dr Simon Bacon, a psychiatrist at the Department of Psychiatry at Duke University Medical Centre in North Carolina.

The responsiveness of the patients hearts was checked by measuring their heart-rate variability (HRV), a sophisticated way of assessing the heartbeat. We can all take someone s pulse by putting a finger on the wrist and counting the number of beats per minute. HRV, which can be measured only electronically, focuses on the time between each beat. If it is unvarying, HRV is said to be low. HRV is a measure of how effectively the brain is switching between the sympathetic (arousing) and parasympathetic (relaxing) parts of your nervous system, says Bacon. A low HRV means that you are stuck in one or the other. HRV is used regularly in intensive care to predict a heart attack victim s chances of survival (a low reading is bad). Bacon s patients showed a lower HRV when they reported negative emotions such as anger, stress or sadness. We found a direct link between emotions and effective autonomic control of the heart, he says.

Further evidence for the damaging effect of negative emotions on the heart via HRV has emerged in the same week in a report from Emory University Hospital in Atlanta on a study of depression in twins. Those pairs who were more depressed also had lower HRV.

This is a plausible mechanism to explain why depression is such a strong risk factor for heart disease, says Dr Viola Vaccarino, a cardiologist at Emory.

But it has been left to a private organisation, the HeartMath Institute in Boulder Creek, California, to explore the possibilities of improving heart health and general well being by consciously raising a person s HRV with positive emotions. The patient s HRV is recorded

using sensors attached to the fingertips; the data is then analysed by a computer program negative emotions produce a pattern that is jagged and irregular, whereas positive emotions appear ordered and coherent (and look rather like a picket fence).

Patients are encouraged to concentrate on positive emotions, and they can then see on the screen how the heart responds, with better feelings producing a more coherent pattern.

It is a technique that has been used to help employees of large American corporations to handle stress. Last year, for instance, one published study found that a small group of stressed workers who were taught to control their HRV not only significantly lowered their blood pressure, but also improved their emotional health. Other reports in journals such as The American Journal of Cardiology have found that there is a 25 per cent improvement in the ability to focus, a 45 per cent reduction in exhaustion and a 41 per cent reduction in intention to leave the job .

© The Times Online 2004