Haemodynamic and electrodermal correlates of psychogenic stimuli in hypertensive and normotensive subjects.

This study compared tonic and phasic cardiovascular and electrodermal activity in subjects having essential arterial hypertension (HT) with that of sex- and age-matched normotensive (NT) controls. Fourteen subjects of each group were subjected to 'sensory intake' (letter identification) and 'rejection' (mental arithmetic) tasks while recordings were made of: systolic and diastolic arterial blood pressure, hand and forearm blood flows, heart rate, skin conductance level and fluctuations. The rejection task affected more physiological variables in both groups than the intake task did. The reaction pattern was similar in both groups. Except for systolic and diastolic blood pressures tonic cardiovascular and electrodermal activity of the HT group was not different from that of the NT group. The same pattern, although less clear cut, was observed when reactivity was studied. According to analyses based on pressure levels both tasks raised the systolic blood pressure of the HT group, whereas only the rejection task raised systolic blood pressure in the NT group. In contrast, an analyses based on blood pressure changes from base to task indicated that both groups increased systolic blood pressure to both tasks. Since virtually no other differences in reactivity were found, this study offers weak support for the notion that subjects having essential arterial hypertension are pressor hyper-reactors.