Autonomic nervous system responses to personal stressful events in patients with acute myocardial infarction. Preliminary results.

Background: Life events specific for each individual may influence the onset of acute myocardial infarction (AMI), and we wondered whether recall of such events elicits autonomic nervous system responses in patients.

Methods: Thirty-one subjects with AMI, which occurred about 1 month previously (study group), and 22 healthy subjects were interviewed. Whenever the presence of a stressful event was found within the last 2 months before AMI onset, a key phrase of the event was isolated. Each subject was faced with 20 written key sentences (including his/her own sentence if detected) at random order, for 40 s each. At the same time the heart rate (HR) and the galvanic skin response (GSR) were continuously recorded. Pearson r correlations, chi 2 and t tests were employed for comparisons between study and control group as well as within each group.

Results: A recent exacerbating event was detected in 30/31 AMI patients and in 0/22 healthy subjects. For the 30 AMI patients the values of HR following the sentence of the suspected event, specific for each patient, were statistically significantly higher than the mean values of HR following the remaining 19 'neutral' statements. The same significant difference appeared with regard to GSR values. The mean values of the AMI patients for the 19 neutral statements did not differ significantly from those of the healthy subjects for the 20 neutral statements, either for HR or GSR.

Conclusions: Findings suggest that recall of personal stressful events elicited autonomic nervous system responses in AMI patients and, therefore, events with personal significance are related to coronary disease onset.