CARDIOVASCULAR, ELECTRODERMAL AND CATECHOLAMINE RESPONSES TO STRESS IN BORDERLINE HYPERTENSIVES

This study was carried out as a further test of the hypothesis that essential hypertensives show increased and prolonged psychophysiological responses to stress. Subjects were 12 male borderline essential hypertensives and 12 male normotensives of the same age group. The study involved a 10-min adaptation period, 10-min baseline, 10-min stress (mental arithmetic) and 16-min follow-up. Systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), skin conductance level (SCL) and number of spontaneous fluctuations in electrodermal activity (SF) were recorded every 2 minutes. Blood samples for determination of plasma adrenaline (A) and noradrenaline (NA) were drawn once in each phase. Hypertensives had significantly higher values of SBP and SF; magnitudes of stress responses did not differ between groups. Hypertensives showed delayed recovery in SF after the cessation of stress; normotensives showed a tendency to recover more slowly as far as NA was concerned. The results of this study do not lend much support to the reactivity hypothesis of hypertension.