Yoga Relaxation (savasana) decreases cardiac sympathovagal balance in hypertensive patients

Abstract

OBJECTIVE: Although relaxation is recommended as complementary therapy for hypertension, its post-intervention cardiovascular autonomic effects are unclear. The objective of this research was to investigate the effects of savasana relaxation on cardiovascular autonomic modulation in hypertensive patients. METHODS: This randomized controlled trial was performed at the Hemodynamic Laboratory of the Physical Education School of the University of Sao Paulo/Brazil. Sixteen hypertensive (6-women) and 14 normotensive patients (6-women) non-obese subjects participated in 2 random sessions: savasana relaxation and control. Patients remained supine for 55 min after interventions. Electrocardiogram, beat-to-beat blood pressure and respiration were acquired during and after interventions for posterior autoregressive spectral analysis of the R-R interval and blood pressure variability. RESULTS: Hypertensive and normotensive patients presented similar cardiac autonomic modulation responses during and after experimental sessions. During relaxation, low frequency and sympathovagal balance were significantly lower in the Relaxation sessions than during supine rest in the Control sessions. Fifteen minutes after interventions, low frequency and sympathovagal balance were still lower in Relaxation than in Control, and remained lower for 35 min; at 55 min, the variables were similar between sessions. Systolic blood pressure variability did not differ among sessions. CONCLUSIONS: Savasana Relaxation decreases cardiac sympathetic autonomic modulation after its performance in hypertensive patients; this reduction lasts at least 35 minutes and is not blunted in hypertensive patients when compared to normotensive controls. Thus, savasana relaxation has positive effects on cardiac autonomic modulation of hypertensive patients, and may be included as a strategy for the non-drug treatment of hypertension.