How Does Heart Rate Variability Biofeedback Work? Resonance, the Baroreflex, and Other Mechanisms

Heart rate variability biofeedback is known to have multiple effects on the cardiovascular system, the respiratory system, and emotional reactivity. This paper reviews the origins of work on heart rate variability biofeedback, and mechanisms for its various effects, including direct effects on the baroreflex system and gas exchange efficiency, as well as indirect effects on emotional reactivity and possibly inflammatory activity. Resonance in the cardiovascular system is explained, as well as ways that heart rate variability biofeedback stimulates these resonance effects, through interactions between respiratory sinus arrhythmia and the baroreflex system. Relationships of these mechanisms to various clinical applications of heart rate variability biofeedback are explored, as are future extensions of biofeedback to the vascular tone baroreflex.