This research addresses the question in different ways. For example, laboratory studies by the research team have found that when people perform tasks while being harassed or are asked to talk about events that make them angry, they show strong increases in heart rate and blood pressure with these responses often related to how angry they get. Other studies involve people outfitted with small wearable devices for measuring various cardiac functions while they go about their daily activities. In these studies it has been found that individuals scoring high on measures of dispositional anger or hostility show significantly greater increases in blood pressure during angry episodes or when they are feeling socially stressed than do those with lower scores.
Of particular interest is the fact that patterns of cardiovascular responses to anger appear to differ among ethnic groups in Singapore in ways consistent with known differences in heart disease rates. In particular, the pattern of physiological response to emotional stressors among Indians corresponds with the fact that they are two to three times more likely to die of heart disease than Chinese are. No one knows at this point what causes these differences in physiological responses though the possibility of genetic connection is being actively investigated.
In order to explore the effects of stress on the heart, the research team has collaborated with researchers from Singapore National Heart Centre (NHC) in a study of the effects of a workshop to help people deal more constructively with stressful situations and build better relationships. This workshop, comprising one two-hour session per week over six weeks, taught skills for evaluating upsetting situations and dealing with negative emotions. It also focused on developing listening and other interpersonal skills. Patients who had recently undergone bypass surgery at the NHC were randomly assigned either to the full workshop or to a comparison group in which they received a one-hour lecture on basic skills but did not get practice in the skills as the workshop's people did.
The results were dramatic. Compared with measurements taken before the series began, workshop participants showed a significant reduction in feelings of depression and perceived stress at the end of the workshop. More importantly, workshop participants showed significant reduction in resting heart rate and blood pressure after completing the workshop and their cardiovascular responses to anger went down substantially, a reduction that was even greater three months after the workshops ended. The comparison group demonstrated none of these changes. These results are currently being followed up with further studies of the use of such interventions with medical patients, looking at both their short and long term effects.