A RECENT study offers fresh insights into how heart rate variability (HRV) measures, both linear and nonlinear, can help detect autonomic nervous system dysfunction in fibromyalgia (FM), a chronic condition marked by widespread pain, fatigue, and mood disturbances. The research demonstrates that combining various HRV proxies, including correlation dimension (D2), provides a valuable tool for assessing disease-related impairments in FM patients.
The study analyzed HRV data from 85 patients with fibromyalgia and compared it to 35 healthy controls during a standardized 5-minute paced breathing task. HRV, a key indicator of autonomic balance, was assessed through both traditional linear indices, standard deviation of normal-to-normal intervals (SDNN), root mean square of successive differences (RMSSD), and total power, and the nonlinear parameter D2. The researchers introduced an HRV grade, a composite score derived from these linear metrics, to better capture global autonomic function.
Findings revealed significant differences in D2 values between patients with FM and healthy controls (p < 0.001), highlighting altered autonomic regulation in fibromyalgia. Among patients with FM, D2 showed strong associations with standard HRV indices (all p < 0.001) and with the Fibromyalgia Impact Questionnaire (FIQ) scores, a clinical measure of disease severity (correlation = -0.4567; p < 0.001). Additionally, the HRV grade correlated positively with FIQ scores (correlation = 0.5058; p < 0.001), reinforcing its potential role in tracking disease burden. These results suggest that integrating multiple HRV measures, particularly nonlinear dynamics like D2, could enhance clinical protocols for monitoring autonomic dysfunction in fibromyalgia. By leveraging HRV grading, healthcare professionals may gain deeper insight into the severity of FM and its related dysautonomia, offering a promising avenue for personalized patient care. Reference: Lombardi F et al. Combined Proxies for Heart Rate Variability as a Global Tool to Assess and Monitor Autonomic Dysregulation in Fibromyalgia and Disease-Related Impairments. Biomedicines. 2024;12:294.
