Effects of Nature-Based Virtual Reality and Binaural Beats on Heart Rate Variability and Relaxation

The VRELAX study is a non-clinical sub-study within the "Decreasing Preoperative Stress to Prevent Postoperative Delirium and Postoperative Cognitive Decline in Cardiac Surgical Patients"- research program (DESTRESS; NCT05036538), which investigates non-pharmacological relaxation interventions using virtual reality and binaural auditory stimulation. In a randomized counterbalanced within-subject design, non-clinical adult participants complete two sessions separated by a 1 day intervention-free interval. A 30-minute immersive nature-based virtual reality exposure combined with gradually decreasing binaural beats (10-1 Hertz (Hz)), and a control condition without relaxation. Heart rate variability (HRV) is recorded continuously, and subjective stress is assessed before and after each condition. The primary outcome is parasympathetic activation operationalized as high-frequency (HF) power of heart rate variability. Secondary outcomes include additional HRV parameters and self-reported stress ratings. The study aims to characterize short-term relaxation effects and evaluate the feasibility of independent use in everyday settings, supporting interpretation of clinical findings of the DESTRESS trial.