Treffer: Cardiac-gated closed-loop auricular vagus nerve stimulation ; Estimulación del nervio vago auricular de circuito cerrado a partir de la sincronización cardíaca ; Estimulació del nervi vague auricular de circuit tancat a partir de la sincronització cardíaca

Percutaneous auricular vagus nerve stimulation (aVNS) is a promising therapy to treat a wide range of diseases by stimulating the auricular branch of the vagus nerve along a well-defined neuroanatomical pathway. It induces systemic changes of the sympathovagal balance of the autonomous nervous system with a minimal invasive procedure. Closed-loop systems in synchronization with patients’ physiological signals are currently undergoing extensive clinical research to achieve a personalized and efficient aVNS treatment. Seven subjects received two 50-minute sessions of percutaneous aVNS, timed to the systolic or diastolic phases, in order to investigate the effects of cardiac cycle synchronization on the parasympathetic nervous system, the vagus nerve is a part of. A tingling sensation was used to determine the applied stimulation threshold voltage. The electrodes were positioned in the auricular cymba conchae, and the stimulus was administered for 10 minutes, with baseline and follow-up phases, in two sessions. Heart rate variability and blood pressure parameters were analysed in the time and frequency domain, using ECG and BP recordings to evaluate the vagal activity. The study revealed low reproducibility between both sessions and the subjects exhibited different parameter tendencies when the two types of stimulation synchronization were applied. The placement of the needle electrodes led to minimal local bleeding. The threshold stimulation voltage applied to the subjects in the first session was generally higher than in the second session. Overall, the findings showed a significant increase of the parasympathetic tone during diastolic-synchronized stimulation than at baseline. Here higher values of RR, rMSSD, HF and TP together with lower LF/HF were obtained, without affecting the blood pressure variables. On the other hand, systolic-synchronization raised blood pressure while having less impact on the vagal tone. The diastolic-synchronized aVNS may enable an effective and personalized therapeutic strategy. ...