The Effect of a Single Episode of Short Duration Heart Rate Variability Biofeedback on Measures of Anxiety and Relaxation States

This study examines the acute effect of heart rate variability (HRV) biofeedback on anxiety and relaxation states. Eighteen healthy males exposed to work-related stress were randomized into an HRV biofeedback group (BIO) or comparative group (COM). The device used by the COM group appeared identical to the HRV biofeedback device, however, it did not provide biofeedback, rather it displayed a wave which the subjects were instructed to observe. Subjects completed a modified Stroop task before and after a 10-min intervention. The Spielberger Trait Anxiety Inventory (STAIT) was completed at recruitment, and the Spielberger State Anxiety Inventory (STAIS) and Smith Relaxation States Inventory 3 (SRSI3) were completed before and after testing. Subjects rated perceived efficacy and feelings of sleepiness using a visual analogue scale (VAS). Analysis of the VAS scores revealed that the COM group felt sleepier than the BIO group after using the intervention. After testing, HRV biofeedback resulted in large improvements in scores for mindfulness, energized positive feelings and basic relaxation, and the comparative intervention resulted in a moderate improvement in basic relaxation, small improvement in mindfulness, and no improvement in energized positive feelings. Both groups had moderate improvements in transcendence. There was a large decrease in state anxiety in the BIO group and moderate decrease in the COM group. These findings suggest that although there was benefit to both interventions, a single episode of short duration HRV biofeedback led to greater benefit and may be a valuable tool to include in the management of acute stress and anxiety.