Background: Cancer may adversely affect patients' heart-rate variability (HRV). We hypothesised that Tai Chi (TC) Qigong practice may improve HRV in survivors of nasopharyngeal cancer (NPC). Purpose: The aim of this study was to explore the changes in HRV in survivors of NPC before, during and after a 5-minute TC Qigong exercise. Methods: Eleven survivors of NPC participated voluntarily in this study. The heart rate (R to R peak intervals) of each participant was measured continuously for 1 minute before the TC Qigong intervention, during the 5-minute TC Qigong intervention and for 1 minute after the TC Qigong intervention, using Polar heart-rate monitors. Spectral HRV was expressed in terms of three components: (1) normalised low frequency (LF) power, (2) normalised high frequency (HF) power and (3) low frequency/high frequency (LF/HF) power ratio. Results: Repeated measures analysis of variance revealed that both the normalised LF-power (p< 0.001) and the normalised HF-power (p< 0.001) had significant time effects. However, the time effect of the LF-/HF-power ratio was not significant (p=0.086). Post-hoc contrast analysis revealed a significant decrease in normalised LF power and a concomitant increase in normalised HF power during the 4th minute (p< 0.001) and 5th minute (p< 0.001) of the TC Qigong exercise. No significant differences were found between the pre- and post-intervention normalised LF power values or the pre- and post-intervention normalised HF power values (p>0.05). Conclusions: As little as 5 minutes of TC Qigong exercise was found to improve HRV by increasing normalised HF power and decreasing normalised LF power, but these effects were transient. Implications: TC Qigong may be an appropriate exercise for improving autonomic nervous system function and psychological and cardiac health in survivors of NPC. However, regular practice may be necessary to maintain these beneficial effects.
|Publication status||Published - May 2015|
Autonomic Nervous System
Analysis of Variance
CitationFong, S. S. M., Chung, J. W. Y., Luk, W. S., & MacFarlane, D. J. (2015, May). Heart-rate variability changes in survivors of nasopharyngeal cancer during Tai Chi Qigong practice. Paper presented at The 17th World Confederation for Physical Therapy Congress, Victoria Charity Centre, Singapore.
- Head and neck neoplasms
- Mind-body therapies
- Heart rate