Dissecting Cardiovascular Responses to a Fixed-Interval Volitional Sighing Protocol Using a Mixed Modeling Approach.
Psychophysiology January 1, 2026 Neel Muzumdar, Kelly Sun, Samuel Zhang et al.
Volitional sighing at fixed intervals produces a sympathetic cardiovascular response similar to exercise, with heart rate, low-frequency heart rate variability, pulse transit time variability, mean arterial pressure, and low-frequency blood pressure variability all increasing significantly from baseline. Greater changes occurred during shorter intervals between sighs (one every 15 seconds versus one every 30 seconds). High-frequency heart rate variability decreased only during the more frequent sighing task. Males showed larger increases than females in heart rate and several sympathetic indices, but smaller decreases in high-frequency heart rate variability. The fixed-interval volitional sighing protocol may serve as a stress test to detect early cardiovascular or autonomic dysfunction.