Acute right-sided transcutaneous vagus nerve stimulation improves cardio-vagal baroreflex gain in patients with chronic heart failure

Fig. 1. Effects of tVNS on cardio-vagal baroreflex gain in patients with chronic heart failure. Acute right-sided—but not left-sided—tVNS increased cardio-vagal baroreflex gain in the study population. Each patient underwent left-sided and right-sided tVNS during the same experimental session, in a randomized order, and separated by a 10-min recovery. One-way ANOVA for repeated measure was used, with Bonferroni correction for post hoc pairwise companions. tVNS transcutaneous vagus nerve stimulation

Fig. 2. Effects of tVNS on cardio-vagal baroreflex gain across patient subgroups. The efficacy of acute right-sided tVNS in increasing cardio-vagal baroreflex gain was consistent across different subgroups in the study population. One-way ANOVA for repeated measure was used. HFmrEF heart failure with mildly reduced ejection fraction, HFrEF heart failure with reduced ejection fraction, tVNS transcutaneous vagus nerve stimulation

Fig. 3. Effects of tVNS on HRV parameters in patients with chronic heart failure. Acute right-sided tVNS was associated with nonsignificant changes in time-domain and frequency-domain HRV parameters toward vagal predominance (all p > 0.05). One-way ANOVA for repeated measure was used. Individual data points for each parameters are reported in Supplemental Figures 1, 2, and 3. HF high frequency, LF low frequency, rMSSD root mean square of the successive differences between normal-to-normal intervals, SDNN standard deviation of the normal-to-normal intervals, tVNS transcutaneous vagus nerve stimulation