A link between emotional stress and heart attacks.

The biological events linking emotional stress and heart attack are poorly understood. Researchers now find that in some people with heart disease, a stressful event precipitates changes in blood components and flow that may trigger a heart attack.

Scientists identified 34 men who had recovered from heart attacks that occurred an average of 15 months earlier. Fourteen had experienced emotional stress, such as arguments with neighbors or sadness about a sick or deceased relative, less than 2 hours before their heart attacks, says Andrew Steptoe, a psychologist at University College London. The other 20 men reported no such stress just before their heart attacks.

Each participant voluntarily completed a series of mentally challenging tests designed to rev up stress. After the tests, the men who had had a stressful event before their heart attacks took longer to stabilize their systolic blood pressures--the high number of the two readings--and heart rate than did the other men, Steptoe and his colleagues report in an upcoming Proceedings of the National Academy of Sciences.

Blood samples drawn immediately after the tests showed that accumulations of platelets bound to immune cells had roughly doubled in the men who had had a stressful event before their heart attacks. The blood reading was unchanged in the other men. High accumulations of platelets can trigger a heart attack in people who have coronary artery disease.

While clinicians can't counsel at-risk patients to avoid emotional upset, Steptoe says, "we can help them cope with problems like uncontrollable anger." --N.S.