Haberbusch Max, Kronsteiner Bettina, Aigner Philipp, Kiss Attila, Podesser Bruno Karl, Moscato Francesco
Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria.
Ludwig Boltzmann Institute for Cardiovascular Research, Vienna, Austria.
Front Physiol. 2024 May 21;15:1379936. doi: 10.3389/fphys.2024.1379936. eCollection 2024.
The influence of vagus nerve stimulation (VNS) parameters on provoked cardiac effects in different levels of cardiac innervation is not well understood yet. This study examines the effects of VNS on heart rate (HR) modulation across a spectrum of cardiac innervation states, providing data for the potential optimization of VNS in cardiac therapies.
Utilizing previously published data from VNS experiments on six sheep with intact innervation, and data of additional experiments in five rabbits post bilateral rostral vagotomy, and four isolated rabbit hearts with additionally removed sympathetic influences, the study explored the impact of diverse VNS parameters on HR.
Significant differences in physiological threshold charges were identified across groups: 0.09 ± 0.06 μC for intact, 0.20 ± 0.04 μC for vagotomized, and 9.00 ± 0.75 μC for isolated hearts. Charge was a key determinant of HR reduction across all innervation states, with diminishing correlations from intact ( = 0.7) to isolated hearts ( = 0.44). An inverse relationship was observed for the number of pulses, with its influence growing in conditions of reduced innervation (intact = 0.11, isolated = 0.37). Frequency and stimulation delay showed minimal correlations ( < 0.17) in all conditions.
Our study highlights for the first time that VNS parameters, including stimulation intensity, pulse width, and pulse number, crucially modulate heart rate across different cardiac innervation states. Intensity and pulse width significantly influence heart rate in innervated states, while pulse number is key in denervated states. Frequency and delay have less impact impact across all innervation states. These findings suggest the importance of customizing VNS therapy based on innervation status, offering insights for optimizing cardiac neuromodulation.
迷走神经刺激（VNS）参数对不同心脏神经支配水平下诱发的心脏效应的影响尚未完全明确。本研究考察了VNS在一系列心脏神经支配状态下对心率（HR）调节的影响，为心脏治疗中VNS的潜在优化提供数据。
利用先前发表的关于六只神经支配完整的绵羊的VNS实验数据，以及五只双侧迷走神经切断术后的兔子和四个额外去除交感神经影响的离体兔心的实验数据，本研究探讨了不同VNS参数对心率的影响。
各实验组间生理阈值电荷存在显著差异：神经支配完整组为0.09±0.06μC，迷走神经切断组为0.20±0.04μC，离体心脏组为9.00±0.75μC。电荷是所有神经支配状态下心率降低的关键决定因素，从神经支配完整组（r = 0.7）到离体心脏组（r = 0.44），相关性逐渐降低。脉冲数量呈现相反的关系，其影响在神经支配减少的情况下增加（神经支配完整组r = 0.11，离体心脏组r = 0.37）。在所有情况下，频率和刺激延迟的相关性最小（r < 0.17）。
我们的研究首次强调，包括刺激强度、脉冲宽度和脉冲数量在内的VNS参数在不同心脏神经支配状态下对心率有至关重要的调节作用。强度和脉冲宽度在神经支配状态下对心率有显著影响，而脉冲数量在去神经支配状态下是关键因素。频率和延迟在所有神经支配状态下影响较小。这些发现表明根据神经支配状态定制VNS治疗的重要性，为优化心脏神经调节提供了见解。
