Heart Rate Variability (HRV) Biofeedback
Heart rate variability (HRV) is an indirect measure of the dynamic interplay between the sympathetic (fight or flight, excitatory) 
nervous system (SNS) and parasympathetic (rest and digest, inhibitory) nervous system (PSNS). These two branches of the autonomic nervous system (ANS) work in concert to maintain physiological homeostasis and, when necessary, ramp up or ramp down physiological processes to meet momentary demands. HRV biofeedback involves the use of one or more sensors that supply real-time feedback about ANS activity. Some of the different noninvasive sensors that might be used during HRV biofeedback include electrocardiogram (ECG/EKG) sensor, blood volume pulse (BVP) sensor, respiration monitoring, skin temperature sensor, galvanic skin response (GSR) sensor, and surface electromyography (sEMG) sensor. HRV biofeedback is an effective adjunctive therapy for a variety of common problems.
Chronic Pain & Headaches
Activation of the PSNS that occurs during HRV biofeedback causes the release of neurotransmitters like acetylcholine (ACh) that are involved in modulating the inflammatory process. Specifically, acetylcholine (ACh) helps reduce inflammation through a mechanism called the cholinergic anti-inflammatory pathway by interacting with immune cells like macrophages to inhibit the release of pro-inflammatory cytokines.
Trauma & Anxiety
Trauma and anxiety trigger the SNS resulting in the release of stress hormones and an increase in heart rate and blood pressure. Activation of the PSNS that occurs during HRV biofeedback counterbalances the fight or flight response by inhibiting the release of stress hormones, slowing heart rate, and reducing blood pressure.
What you Should Know About HRV Biofeedback
Patients should arrive dressed in comfortable clothes that will permit active participation. Please let your therapist
know if you are experiencing any respiratory problems or acute illness. Biofeedback may not be appropriate for individuals struggling with chronic respiratory or cardiac illness. You should tell your therapist if you experience shortness of breath, lightheadedness, or dizziness. Please avoid caffeine during the hours before your biofeedback session.