Abstract
BACKGROUND: Nadi shodhan pranayama, which is also known as Anulom-vilom pranayama or alternate nostril breathing, has been demonstrated to elicit a decrease in systolic blood pressure (SBP), diastolic blood pressure (DBP) and heart rate, owing to its stress-reducing effects. One of the most promising quantitative markers of autonomic activity is heart rate variability (HRV). PURPOSE: This study was done to study the immediate and long-term effects of 10 minutes of nadi shodhan pranayama, preceded by two minutes of yogic deep abdominal breathing, on blood pressure and other autonomic parameters. METHODS: Baseline parameters of BP, HRV, Pittsburgh Sleep Quality Index (PSQI) and Hamilton Anxiety Rating Scale (HAM-A) were measured at first visit. Patients were randomised into test and control groups, and the test group was given intervention. BP and HRV were measured once again immediately after intervention for test subjects. After six weeks, BP, HRV, PSQI and HAM-A were repeated. RESULTS: Immediately after the intervention, the test group showed a significant reduction in SBP, DBP and mean heart rate (MHR) with an increase in R-R interval, standard deviation of the NN interval (SDNN), the square root of the mean squared differences of successive NN intervals and high frequency. At follow-up, the test group had a lower SBP and low frequency/high frequency ratio and a higher SDNN and total power, compared to the control group. CONCLUSION: The practice of nadi shodhan pranayama, preceded by two minutes of yogic deep abdominal breathing, reduced the systolic and diastolic BP and improved HRV-related autonomic parameters, in patients of hypertension on pharmacological therapy, immediately after 10 minutes of practice and after 10 minutes of daily practice for six weeks.