Biofeedback Using Virtual Reality and Yoga Pranayama Modulates Blood Pressure and Heart Rate Variability in People with and without Cervical Spinal Cord Injuries.

Techniques for rapid blood pressure modification without the side-effects associated with pharmaceuticals are urgently needed, especially for individuals with spinal cord injuries above thoracic level six (T6). Such cervical injuries lead to sympathetic nervous system dysfunction, negatively affecting cardiovascular health and quality of life. Our biofeedback protocol aimed to teach participants to self-modulate their blood pressure using yoga breathwork (kapalabhati and brahmari pranayama), virtual reality imagery, autogenics, and interoceptive attention. In this cohort study, we trained 13 participants with spinal cord injuries and 7 noninjured controls for 1 hour per session across 8 sessions in a month. The goal was to decrease mean arterial pressure by at least 5 mmHg during relaxation cycles and increase it by at least 5 mmHg during stimulation cycles. We assessed hemodynamic responses to head-up tilt testing, the Valsalva maneuver, and paced deep breathing before and after the 8 trainings and evaluated quality of life and interoception with qualitative surveys. Heart rate variability changes were also assessed. The protocol was effective in modulating mean arterial pressure and heart rate variability in individuals with chronic cervical spinal cord injuries, as well as in noninjured control participants.