By Lim Wey Wen

THE list of risk factors for heart disease e-mailed to me by senior consultant psychiatrist Prof Ainsah Omar looked run-of-the-mill, but for two factors: "Type A personality, and stress".

Until recently, the effects of these two as risk factors for heart disease have been mostly observational and retrospective.

In the Los Angeles earthquake in 1994, half of all immediate deaths were found to be due to cardiac arrests - five times greater than a usual day.

Soon after, many other incidents indicated that physical and emotional triggers, such as environmental disasters and vigorous physical exercise (particularly in those who are already at risk), can precipitate heart attacks.

Two years ago, a landmark global study - the INTERHEART study - managed to provide us with some numbers.

Using questionnaires, researchers compared 15,152 cases of heart attacks to 14,820 controls in 52 countries to find out if risk factors for heart attacks impact people of different races or from countries differently.

One notable finding was that psychosocial risk factors were more common amongst those who had heart attacks.

From the study findings, it was estimated that if psychosocial risk factors alone (including stress and depression) were eliminated, 32.5% of heart attacks could be prevented.

The same study estimated that eliminating lifetime smoking alone would reduce heart attacks by 35.7%. Eliminating hypertension would reduce heart attacks by 17.9% and eliminating obesity would reduce the incidence by 20.0%.

Who knew preventing a heart attack could also be just one positive thought, or therapist, away?