Abstract

Traumatic brain injury (TBI) affects over 1.7 million people annually in the U.S., often leading to autonomic nervous system (ANS) dysregulation and reduced heart rate variability (HRV), which may impact cognitive performance. This study investigated whether HRV biofeedback (HRV-B) improves HRV at rest and recovery after stress in individuals with TBI. Secondary aims examined links between HRV improvements and reductions in physical symptoms, enhanced emotional functioning, and better cognitive performance, as well as the role of practice adherence in moderating HRV-B effects. This randomized controlled trial compared HRV-B treatment to a sham control using a pre- and post-assessment design. Of 58 participants with TBI, 49 completed the study (HRV-B: 25, mean age 27.1 Â± 9.7 years; sham: 24, mean age 26.6 Â± 9.9 years). Participants underwent five weekly sessions, and assessments included cognitive, emotional, and physical measures. Heart rate variability data, encompassing both frequency-domain metrics (e.g., HF, LF, LF/HF ratio) and time-domain metrics (e.g., SDNN, RMSSD), were obtained through electrocardiogram recordings. At rest, a significant group main effect was found for the LF/HF ratio (F(1, 43) = 9.38, p = 0.004), with the HRV-B treatment group demonstrating an increase in the LF/HF ratio compared to the sham group after treatment. During stressor recovery, the LF/HF ratio differed significantly between groups (F(1, 172) = 4.27, p = 0.040), with the HRV-B group values higher than the sham group. A significant group-by-session interaction for the LF/HF ratio (F(1, 172) = 4.18, p = 0.04) further indicated an increase in the LF/HF ratio over time following a stressor in the HRV-B group compared to the sham control. For cognitive outcomes, session effects were significant for both the Fluid Cognition Composite Score and the Total Composite Score, suggesting improvement over time in both groups, although no differences were observed between the HRV-B and sham groups. Session significantly influenced anxiety and depression, with the HRV-B group showing notable improvement in depression, while no significant group effects were observed for stress and life satisfaction. Individuals with TBI who received HRV-B showed higher LF/HF ratio values at rest and during stressor recovery compared to the sham group, driven by enhanced LF components indicative of improved autonomic regulation and stress resilience. While cognitive and emotional improvements were observed across groups, the absence of condition-specific effects underscores the need for larger studies with extended interventions to clarify the unique benefits of HRV-B for TBI recovery.

Degree

PhD

College and Department

Family, Home, and Social Sciences; Psychology

Rights

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