Exploring the Feasibility of Heart Rate Variability Biofeedback for Individuals With Tetraplegia: A Pilot Clinical Trial

Purpose/Objective: This study aimed to determine the feasibility of using commercially available heart rate variability (HRV) biofeedback training to improve physiological and self-reported stress and anxiety among adults with tetraplegia. HRV biofeedback teaches individuals to effectively modify their HRV levels in synchronization with their respiration rate and amplitude. Research Method/Design: Thirty participants with tetraplegia were enrolled and allocated into one of two study arms: biofeedback or control. The study was conducted remotely from June 2022 through February 2023. Participants in the biofeedback arm received eight HRV training sessions with physiological monitoring, while participants in the control arm received physiological monitoring only. Outcome measures included feasibility, percentage of time spent in the low-frequency range, the Depression Anxiety Stress Scale-21, the Subjective Units of Distress Scale, and the State-Trait Anxiety Inventory-Y Form. Results: Feasibility was demonstrated with 100% completion of the protocol and no participant withdrawals due to adverse events. The biofeedback arm showed a greater percentage of time spent in the low-frequency range and reported greater improvement in anxiety from baseline to Session 8 on the Subjective Units of Distress Scale compared to the control arm. However, no differences were found between study arms on the Depression Anxiety Stress Scale-21 and State-Trait Anxiety Inventory-Y Form. Conclusions/Implications: This study demonstrated that a remotely delivered, self-administered HRV biofeedback intervention could feasibly be delivered to individuals with tetraplegia who report moderate-to-high levels of anxiety. Trends in the reduction of physiological and self-reported anxiety were observed.