Madanmohan*, A. B. Bhavanani, E. S. Prakash,M. G. Kamath and J. Amudhan
Department of Physiology, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER) Pondicherry – 605 006
In an earlier work from our laboratory, we have actually demonstrated the effectiveness of shavasan, a yogic relaxation technique, in producing psychosomatic relaxation (1). The blood tension (BP) lowering effect of shavasan has actually been demonstrated previously in subjects along with hypertension (2). The cardiovascular effects of shavasan may at least in part be due to its effects on autonomic regulation of heart rate and blood pressure. Heart rate variability (HRV) analysis has actually come to be increasingly used in physiologic research studies as a noninvasive tool to examine the autonomic regulation of cardiovascular function. It describes the variability in instantaneous heart rates and assesses modulation of cardiac cycle time by intrinsic biological rhythms (3, 4, 5). Oscillations in instantaneous heart rates occur at high frequencies (0.15-0.40 Hz), reasonable frequencies (0.04-0.15 Hz) and at very reasonable frequencies (0.003-0.04 Hz) due to different physiologic mechanisms and these have actually been inferred from pharmacologic studies (3, 4, 5, 6). For a detailed discussion of the physiologic foundations of HRV, consult Akselrod (3, 4), Eckberg (5) and Pagani et al (6). Time domain analysis is a simple method to quantify overall HRV whereas power spectral analysis provides a means of studying different mechanisms responsible for variability in instantaneous heart rates. Raghuraj et al have actually studied the effect of two yogic breathing techniques on heart rate variability (7). The effect of shavasan training on HRV has actually not been studied so far. Hence, we planned to determine whether shavasan training of short duration has actually any effect on the reasonable frequency and high frequency components of heart rate variability.