In a study of 300 people, those with higher activity in the amygdala were more likely to develop cardiovascular disease - and sooner than others.
Stress could be as important a risk factor as smoking and high blood pressure, the US researchers said.
Heart experts said at-risk patients should be helped to manage stress.
Emotional stress has long been linked with an increased risk of cardiovascular disease (CVD), which affects the heart and blood vessels - but the way this happens has not been properly understood.
This study, led by a team from Harvard Medical School, points to heightened activity in the amygdala - an area of the brain that processes emotions such as fear and anger - as helping to explain the link. Continue reading.
Originally posted on BBC News Health.