Parasympathetic Versus Sympathetic Changes in Heart Rate Variability After a Multimodal Integrative Medicine Intervention for Frontline COVID-19 Personnel

Objective: Frontline healthcare providers (HCPs) working in COVID-19 hospital departments need to deal with considerable physical and emotional stress on a daily basis. We conducted a pilot study to examine changes in heart rate variability (HRV) in frontline COVID-19 personnel after an integrative medicine (IM) intervention. Methods: HCPs working in isolated COVID-19 inpatient departments underwent a single 30-minute individually tailored IM sessions combining various IM modalities (acupuncture, mind-body, and/or manual-movement modalities, including anthroposophic medicine). HRV parameters were compared during the first IM session at 3-minute intervals, at the beginning of treatments, and after 20 minutes. Root mean square of successive RR interval differences (RMSSD) was measured, as were domains of time (standard deviation of NN intervals, percentage of successive RR intervals that differ by more than 50 milliseconds) and frequency (low frequency/high frequency [LF/HF] ratio). Preintervention and postintervention concerns were assessed using the Measure Yourself Concerns and Well-being questionnaire, with posttreatment free-text narratives analyzed for clusters of emotional- and spiritual-related keywords (ESKs). Results: A total of 114 HCPs underwent an IM treatment session, and their HRV values were measured, of which 75 (65.8%) expressed ESKs. The RMSSD increased only in the ESK-expressing group (p < .001). LF/HF ratios decreased in both groups, with HF power increasing in the ESK-expressing (p = .043) and LF power decreasing in the non-ESK-expressing groups (p = .004). Conclusions: Increased parasympathetic activity was observed in all HCPs after the IM intervention, particularly among those expressing ESKs. LF/HF parameters suggest different relaxation-associated mechanisms, with increased HF (regulated predominantly by parasympathetic tone) in the ESK-expressing and decreased LF (regulated partially by sympathetic tone) in the nonexpressing group. Additional research needs to explore the relationship between subjective effects of the IM intervention and physiological mechanisms of relaxation in HCPs working in stressful environments.