Pilot Study of Real-World Monitoring of the Heart Rate Variability in Amyotrophic Lateral Sclerosis

Abstract

AimsCardiovascular dysautonomia may impact the quality of life and survival in amyotrophic lateral sclerosis (ALS). Such dysfunction is not systematically assessed in these patients. Wearable devices could help. The feasibility of a wearable biosensor to detect heart rate variability (HRV), a physiological marker of sympathovagal balance, was studied for the first time in real-world settings in ALS.MethodsFive ALS patients (two early/three late; one bulbar-onset; mildly-to-moderately disabled) and five age/sex/BMI/comorbidities-matched controls underwent assessment of 3-day HRV via VitalConnect biosensor (worn on the left thorax). De-identified data captured by the biosensor were transferred to a secure cloud server via a relay Bluetooth device. Baseline ALS severity/anxiety and physical activity during testing were documented/quantified. Time-domain HRV measures (i.e., pNN50) were analyzed.ResultsAn overall 3-day abnormal HRV (pNN50 < 3%), was found in three out of five patients (mean ± SD for the group, 2.49 ± 1.51). Similar changes were reported in controls (12.32 ± 21.14%). There were no statistically significant relationships between pNN50 values and baseline anxiety or physical activity during the tested days (p > 0.05 for both groups). A negative correlation was found between pNN50 values and age in patients (p = 0.01) and controls (p = 0.09), which is similar with what is found in the general population. In line with prior studies, pNN50 values were independent of disease stage (p = 0.6) and disability (p = 0.4).ConclusionsThese preliminary results suggest that remote HRV measures using the VitalConnect is feasible and may constitute an improved strategy to provide insights into sympathovagal balance in ALS. Further work with larger sample sizes is warranted.

Analysis of Heart Rate Variability in Individuals Affected by Amyotrophic Lateral Sclerosis

“…In terms of SDNN, values within the normal range in our healthy group were observed, but these were significantly lower in the ALS group (30.07 ms). This aligns with the findings of Brown et al [33], who, after measuring for 3 days, reported similar results. Values below 35 are considered a high health risk due to ANS weakness [16], and an SDNN interval below 19 ms is associated with imminent death within a year [24].…”

Dysautonomia in Amyotrophic Lateral Sclerosis

“…In a recent small pilot study, the researchers carried out HRV measurements over three days using a non-invasive biosensor. They emphasized the necessity of following the patients from the perspective of obtaining valuable data about non-motor symptoms, but also to better monitor them using non-invasive methods in such fragile individuals [47].…”

Sympathetic neuropathology is revealed in muscles affected by amyotrophic lateral sclerosis

“…Such an already wide spectrum of cells participating in the disease may further extend upon appreciation that subclinical alterations in autonomic control of organ functions are frequently present in ALS patients and that the early manifestations of ALS occur in peripheral tissues and involve muscle atrophy and weakness, NMJ alterations, and metabolic changes (Shimizu et al, 1994;Baltadzhieva et al, 2005;Pavlovic et al, 2010;Merico and Cavinato, 2011;Shimizu et al, 2011;Shimizu, 2013;Dalla Vecchia et al, 2015;De Maria et al, 2015;Piccione et al, 2015;Nolano et al, 2017;Rosenbohm et al, 2017;Pimentel et al, 2019;Silveira et al, 2022). Analysis of heart rate variability (HRV) (Pimentel et al, 2019;Brown et al, 2022) and systolic arterial pressure variability (SAPV) revealed altered sympatho-vagal balance (Moreau et al, 2012;Xia et al, 2022), and microneurography demonstrated a reduced spontaneous activity of sympathetic efferences in sciatic nerves, suggestive of neurodegeneration (Donadio and Liguori, 2015). The same trial has demonstrated that SOD1 G93A mice show a 24% decrease in TH expression in adrenal glands (Kandinov et al, 2013).…”