Abstract

This study explored three issues in rlation to Diastolic Blood Pressure(DBP). These were (1) Is it possible for subjects to control DBP by DBP biofeedback training? (2) What extent can instructions demanding the change of BP without feedback influence on DBP control? (3) What relationship does exist between DBP and HR? Normotensive 42 subjects were counterbalanced and allocated into six groups. So each group had 7 subjects. The six groups were (1) Feedback-Increase group, (2) Feedback-Decrease Group, (3) Instructions-Increase Group, (4) Instructions-Decrease Group. (5) Random. (noncontingent) Group and (6) No-feedback (vigilance) Group. All subjects participated in whole procedure consisted of 3 sessions. One session consisted of 20 main trials. We defined one trial as 50 heartbeats. During each session all subjects had adaptation period(10 min.), baseline trials and 20 main trials. And they received visual feedback of BP change per every heartbeat on computer monitor, according to the BP measurement procedure of Shapiro et al. The results showed that (1) In Feedback-Increase Group, both DBP and HR increased simultaneously and in Feedback-Decrease Group, subjects decreased their BP ony 2mmHg. (2) The subjects of the groups with feedback could control DEP better than those received only instructions. (3) There was the tendency of integration of subjects' DBP with HR. These results suggest that it is not easy for the normotensive to decrease their DBP .and that the DBP biofeedback training would be helpful to the treatment of postural (orthostatic) hypotension, effectively.