Evaluation of Biofeedback in the Treatment of Borderline Essential Hypertension1

Abstract

Direct biofeedback of blood pressure was compared with frontal EMG biofeedback and with self-instructed relaxation for the treatment of essential hypertension in a controlled group outcome study. Patients were followed up for four months after the end of treatment. Generalization of treatment effects was assessed through pre- and posttreatment measurements of blood pressure under clinical conditions in a physician's office. There were no significant reductions in diastolic blood pressure. The systolic blood pressure (SBP) of the patients receiving blood pressure biofeedback decreased 8.1 mm mercury (p = 0.07) and the SBP of the patients in the relaxation condition decreased 9.5 mm mercury (p = 0.05). In the generalization measures, there were significant reductions in SBP for the relaxation group. The results are discussed in terms of the general lack of replicability within the area of biofeedback treatment of hypertension.

Relaxation therapies for the management of primary hypertension in adults: a Cochrane review

“…Entry criteria varied between trials, and the average baseline SBP of participants ranged between trials from 130 to 164 mm Hg (median: 144, inter-quartile range: 139-150 mm Hg) and the corresponding DBP from 86 to 109 mm Hg (median: 92, inter-quartile range: 89-97 mm Hg). Thirteen trials enrolled a mixture of participants who were and were not being treated with antihypertensive medication; [30][31][32][33][34][35][36][37][38][39][40][41][42] nine trials enrolled only participants who were not receiving antihypertensive medication, [43][44][45][46][47][48][49][50][51] although two of these trials enrolled participants who had previously been on medication; 45,47 one trial enrolled only participants who were receiving antihypertensive medication 52 and two trials did not specify the medication status of participants. 53,54 One trial enrolled only participants with a 'Type A' personality: a tendency to anger and hostility.…”

“…32,34,44 Several trials combined components from several types of relaxation therapies in one active treatment arm. Relaxation interventions included: progressive muscle relaxation (16 trials) 30,31,[34][35][36][37]39,40,42,43,46,47,48,[51][52][53] ; biofeedback (12 trials) 32,34,35,[37][38][39][40][41]45,46,48,52 ; autogenic training (6 trials) 33,35,38,39,49,51 and cognitive or behavioural therapy or meditation (11 trials). 32,36,37,40,42,44,46,[49][50][51]54 Within these categories, interventions were heterogeneous.…”

“…32,36,37,40,42,44,46,[49][50][51]54 Within these categories, interventions were heterogeneous. Biofeedback included biofeedback of heart rate, 32 BP, 34 DBP and electrocardiogram, 35 forehead 41 It was generally used in combination with progressive muscle relaxation, sometimes also with cognitive and behavioural therapy, but in one trial it was used with autogenic training alone 38 and in one trial it was not combined with any other therapy. 41 Cognitive and behavioural therapies included anger control, 32 40 Most trials which taught progressive muscle relaxation encouraged participants to practise at home, often with the help of taped instructions; 31,35,39,40,43,46,47,51,53 some trials also encouraged participants to practise these relaxation techniques in stressful situations.…”

“…36,40,47 Relaxation therapies were delivered to participants either in a group setting 32,35,39,40,[42][43][44][45][46][51][52][53] or individually; 30,31,36,37,41,[47][48][49] in five trials the delivery setting was unclear. 33,34,38,50,54 The median duration of treatment was 8 weeks (range: 5-26 weeks).…”

“…Sham therapy variously included mild physical exercise; 30,37,49 biofeedback of galvanic skin resistance; 37,42 sham biofeedback of BP; 35 encouragement of relaxation; 34,46,51,53 counselling on stress;…”