Quantitative evaluation of heartbeat interval time series using Poincaré analysis reveals distinct patterns of heart rate dynamics during cycles of vagus nerve stimulation in patients with heart failure

Abstract

Quantitative Poincaré analysis reveals a tight coupling in beat-to-beat dynamics during VNS ON cycles that is directly related to stimulation intensity, providing a useful measurement for confirming autonomic engagement.

Neuromodulation for Drug-Refractory Epilepsy and Chronic Heart Failure: Targets, Delivery, Composition and Titration

“…The effect of VNS on instantaneous heart rate has consisted of a shift in the centroid of the beat-to-beat cloud distribution of R-R intervals (Figure 6), with a tight coupling in beat-to-beat dynamics during VNS stimulation that has been directly related to stimulation intensity. This has provided a useful measurement for confirming an appropriate level of autonomic engagement [50]. This coupling has been achieved and maintained without any long-term side effects [50,68], and has been associated with significant and clinically meaningful improvements in HF symptoms, exercise capacity, and cardiac function [32,34,52].…”

“…Abbreviations: ms: Milliseconds; RR N : The time between two successive R-waves (ventricular electrograms); RR N+1 : The time between the next two successive R-waves; SD1: Instantaneous beat-to-beat variability in successive RR intervals; SD2: Standard deviation of continuous beat-to-beat R-R interval variability; SD1/SD2: A measure of autonomic balance with higher values correlating with vagal tone preponderance. From Libbus I. J Electrocardiol 2017 (with permission) [50].…”

“…The pulse frequencies for VNS in this study and its long term follow-up were selected to be similar to the spontaneous frequency observed in the efferent fibers of the vagal trunk ( Figure 3A, Panel C) [48]. In this study, VNS successfully engaged the ANS in all patients while they were receiving standard of care treatment with Guideline Directed Medical Therapy (GDMT), as indicated by real-time changes in HR [49,50]. There was also a significant long term decrease in 24-hour heart rate and a significant increase in 24-hour heart rate variability, which are compatible with a sustained improvement in autonomic tone.…”

Vague nerve stimulation in chronic heart failure: is it worth it?

“…Obtaining a tight coupling in beat-to-beat dynamics during VNS directly related to stimulation intensity could provide a useful measurement for confirming autonomic engagement. This new technique for detecting acute heart rate responses to VNS suggests that the recruitment of nerve fibers responsible for heart rate changes were substantially lower in NECTAR-HF than in pre-clinical models [18].…”

“…New techniques (e.q. quantitative Poincaré analysis) were developed in patients with heart failure who received chronic autonomic regulation therapy with an implantable VNS system on either the right or left side [18]. Obtaining a tight coupling in beat-to-beat dynamics during VNS directly related to stimulation intensity could provide a useful measurement for confirming autonomic engagement.…”