A44-31 The Effects of a Brief Pranayama Intervention on Heart Rate Variability in Patients Living With COPD: A Pilot Study

Abstract Rationale Stress is a negative emotional experience that affects people living with COPD, impacting the balance of the autonomic nervous system. Autonomic dysfunction correlates with acute exacerbations of COPD (AECOPD). Heart rate variability (HRV) is frequently used as a surrogate to measure autonomic function. There is little evidence on whether pranayama-based breathing exercises, a common stress reduction technique, can improve heart rate variability in COPD. We aimed to explore whether a brief controlled breath intervention impacts HRV in a randomized pilot study. Methods Twenty individuals with COPD who experienced stress were randomized into 2 groups assigned to either education on smoking cessation, vaccination, and inhaler use or the same education plus Pranayama (15 minutes: 3-part dirgha breath, alternate nostril breathing, and 2:1 breathing) over an 8-day period. HRV was measured via 30-second ECG on day 0 and on day 8 before and after performing controlled breathing exercises or usual breathing. Two time domain metrics were calculated: standard deviation of NN intervals (SDNN) and root mean square of successive differences (RMSSD). Difference of differences (DoD) was calculated between treatment and control groups pre and post intervention or usual breathing. Standard errors were calculated using a linear mixed effect model. Measurements were taken to capture the effect of a single session (Day 8 pre to post) of pranayama exercises as well as one week (Day 0 to Day 8 post) of pranayama practice. Results Nineteen patients had EKG data and were included in the study (11 in intervention; 8 in control). In the total sample, 47% were female and the mean age was 72. From Day 8 pre- to post-intervention, SDNN and RMSSD had a greater improvement in the intervention group compared to the control (SDNN DoD(SE): 8.94 milliseconds (ms)(5.20); RMSSD DoD(SE): 7.99 ms (4.40)). From day 0 (baseline) to day 8 post, there was a similar greater increase in SDNN and RMSSD for the intervention group compared to the control group (SDNN DoD(SE): 13.05 ms (5.26); RMSSD DoD(SE): 11.99 ms (4.41)) (Figure 1). Discussion A brief pranayama intervention led to improvements in HRV after a single session and over the course of 1 week. While this study was not powered to detect a statistical difference in HRV among groups, this preliminary data suggests that pranayama should be examined in a larger clinical trial as a tool to improve HRV in patients with COPD who experience stress. This abstract is funded by: NIH