Heart rate variability and meditation with breath suspension.

Increased high frequency and decreased low frequency powers in heart rate variability (HRV) have been found during various forms of meditation. However, advanced stage of meditation drew less attention to date. We aimed at exploring HRV characteristics during advanced meditation. Heart rate (HR), blood pressures (BP), and parameters of HRV in time and frequency domains of a single meditator were collected during rest, breath meditation, and in advanced meditative stage with breath suspension in 10 meditative sessions. Friedman test was used to compare the variables during different meditative phases. HR and BP revealed significant differences during different meditative phases. Pair-wise comparison revealed that HR decreased continuously and significantly while meditation advanced. On the other hand, none of HRV parameters reached statistical significance. Our findings reveal no significant differences between different meditative phases in terms of HRV parameters, but HR and BP continuously decrease while meditation advances. The discrepancy could be partially attributed to different meditative techniques