Why stress triggers heart attacks

UNITED STATES: The reason why stress causes heart attacks and strokes may finally have been discovered by scientists, leading to hopes it could be prevented.

For years experts have been puzzled as to how anxiety leads to heart problems.

But now they have found that people who have heightened activity in a part of the brain linked to stress – the amygdala – are more likely to develop cardiovascular problems.

The amygdala tells the bone marrow to produce more white blood cells to fight infection and repair damage when faced with a harmful experience, such as being punched, and would have been vital in our evolutionary past.

However, in the modern world, chronic stress can lead to the overproduction of white blood cells, which can form plaques in the arteries and lead to heart disease, scientists believe.

‘‘Our results provide a unique insight into how stress may lead to cardiovascular disease,’’ said lead author Dr Ahmed Tawakol, of Harvard Medical School and Massachusetts General Hospital.

‘‘Eventually, chronic stress could be treated as an important risk factor for cardiovascular disease, which is routinely screened for and effectively managed like other major cardiovascular disease risk factors.’’

Smoking, high blood pressure and diabetes are known risk factors for cardiovascular disease but researchers say chronic social stress should also now be seen as a major danger.

In this study, 293 patients were given scans to record the activity of their brain, bone marrow, spleen and inflammation of their arteries.

They were then tracked for an average of 3.7 years and in this time 22 patients had cardiovascular events, such as a heart attack.

Those with higher amygdala activity had a greater risk of subsequent cardiovascular disease and developed problems sooner.

The researchers also found heightened activity in the amygdala was linked to increased bone marrow activity and inflammation in the arteries, a cause of raised cardiovascular risk.

Dr Ilze Bot, of Leiden University in the Netherlands, said: ‘‘These clinical data establish a connection between stress and cardiovascular disease, thus identifying chronic stress as a true risk factor for acute cardiovascular syndromes.’’ – Telegraph Group

PHOTO: REUTERS Scans of a brain, bone and artery were used in a study carried out by Massachusetts General Hospital and Harvard Medical School which associates the brain region called the amygdala, an area linked to stress, to greater risk of heart disease and stroke.