Utilising Continuous HRV Biofeedback Data for Autonomic Nervous System Regulation in ME/CFS Relapse Management

Abstract Background: Myalgic Encephalomyelitis (ME/CFS), is a long-term, multi system disease characterised by profound, unrefreshing fatigue, pain, cognitive dysfunction, and post exertional malaise (PEM). Heart rate variability (HRV) measures the variation in time intervals between heartbeats to provide an objective indicator of autonomic nervous system (ANS) regulation and resilience. HRV tracking is used to assess autonomic dysfunction in ME/CFS and hypothesised to serve as an early warning system for predicting PEM and prioritising rest. To date there is little research on the use of continuous HRV (C-HRV) tracking, versus baseline HRV and HR monitoring as a pacing and ANS management tool. This case reports a 63 year old female with a 7 year history of stable ME/CFS who experienced a severe symptomatic relapse following a period of physical and psychosocial stress. The patient’s primary concerns were reduced functional capacity, frequent PEM and immune system flares. Method: The subject used real time C-HRV tracking using an electrocardiogram (ECG) grade Firstbeat Life device and engaged in regular health coaching with an HRV trained coach for lifestyle support and HRV data interpretation. The aim of this study was to assess the effectiveness of C-HRV tracking with expert HRV analysis for understanding and improving ANS regulation to help manage energy, and improve functional capacity. Results : Over the 11-week intervention, C-HRV biofeedback showed enhanced ANS regulation, increased baseline HRV, and improvements in perceived cognitive stability and energy. The patient improved her autonomic awareness, PEM predictability, identification of recovery barriers, and effectiveness of specific ANS strategies. A key finding was a lagging HRV response during immune system flares, despite immediate flu-like symptoms, which aligns with established neuroimmune models. This suggests HRV’s role as an early warning system is state and system dependent, and the ANS and immune system may generate different HRV responses.