Heart rate variability as a non-invasive biomarker of autonomic dysfunction in amyotrophic lateral sclerosis: A systematic review and meta-analysis.

OBJECTIVE

This study assessed heart rate variability (HRV) alterations in amyotrophic lateral sclerosis (ALS) patients compared to healthy control groups using both frequency-domain and time-domain HRV parameters.

METHODS

A systematic review and meta-analysis were conducted using studies retrieved from PubMed, Embase, Web of Science, and Cochrane Library databases up to November 13, 2024. Fourteen studies were included in the qualitative synthesis and eight in the quantitative analysis.

RESULTS

ALS patients exhibited significantly reduced Low Frequency (LF) and High Frequency (HF) HRV parameters compared to healthy controls (p < 0.001 and p = 0.02, respectively). Time-domain parameters also showed significant reductions: RMSSD (p < 0.001), SDNN (p < 0.001), and pNN50% (p = 0.01). Despite an overall decrease in HRV, the LF/HF ratio did not show a statistically significant difference (p = 0.12).

CONCLUSION

Patients with ALS demonstrate autonomic dysfunction, evidenced by significant reductions in key time-domain (RMSSD, SDNN, pNN50%) and frequency-domain (LF, HF) parameters, suggesting impaired parasympathetic modulation. HRV may serve as a valuable, non-invasive biomarker for the early detection and management of cardiorespiratory complications in ALS.