BioRobotics Institute, Department of Excellence in Robotics & AI, Scuola Superiore Sant'Anna, Pisa, Italy.
Unit of Translational Critical Care Medicine, Laboratory of Basic and Applied Medical Sciences, Interdisciplinary Research Center "Health Science," Scuola Superiore Sant'Anna, Pisa, Italy; Al-Farabi Kazakh National University, Almaty, Kazakhstan.
Int J Cardiol. 2024 Jan 1;394:131349. doi: 10.1016/j.ijcard.2023.131349. Epub 2023 Sep 7.
The impact of acute unilateral injury on spontaneous electrical activity in both vagus nerves at the heart level is poorly understood. We investigated the immediate neuroelectrical response after right or left cardiac vagal nerve transection (VNTx) by recording spiking activity of each heart vagus nerve (VN).
Fourteen male Göttingen minipigs underwent sternotomy. Multi-electrode cuffs were implanted below the cut level to record vagal electroneurographic signals during electrocardiographic and hemodynamic monitoring, before and immediately after cardiac VNTx (left: L-cut, n = 6; right: R-cut, n = 8).
Left cardiac VNTx significantly reduced multi-unit electrical activity (MUA) firing rate in the vagal stump (-30.7% vs pre-cut) and intact right VN (-21.8% vs pre-cut) at the heart level, without affecting heart rate, heart rate variability, or hemodynamics. In contrast, right cardiac VNTx did not acutely alter MUA in either VN but slightly increased (p < 0.022) the root mean square of successive RR interval differences (rMSSD), an index of parasympathetic outflow, without affecting hemodynamics.
Our study reveals an early left-lateralized pattern in vagal spiking activity following unilateral cardiac vagotomy. These findings enhance understanding of the neuroelectrical response to vagal injury and provide insights into preserving vagal outflow after unilateral cardiac vagotomy. Importantly, monitoring spiking activity of the cardiac right VN may predict onset of left vagal pathway injury, which is detrimental to cardiac patients and can occur as a complication of catheter ablation for atrial fibrillation.
急性单侧损伤对心脏水平双侧迷走神经自主电活动的影响知之甚少。我们通过记录每个心脏迷走神经（VN）的放电活动，研究了右侧或左侧心脏迷走神经切断术（VNTx）后即刻的神经电反应。
14 只雄性哥廷根小型猪接受了开胸术。在进行心电图和血流动力学监测的同时，将多电极袖套植入切断水平以下，以在心脏 VNTx 之前和之后（左侧：L 切断，n=6；右侧：R 切断，n=8）记录迷走神经神经电图信号。
左侧心脏 VNTx 显著降低了迷走神经残端（-30.7%与术前）和完整右侧 VN（-21.8%与术前）的多单位电活动（MUA）放电率，而不影响心率、心率变异性或血流动力学。相比之下，右侧心脏 VNTx 并没有急性改变双侧 VN 的 MUA，但略微增加了连续 RR 间期差异的均方根（rMSSD）（p<0.022），这是副交感神经输出的一个指标，而不影响血流动力学。
我们的研究揭示了单侧心脏迷走神经切断术后迷走神经放电活动的早期左侧偏侧化模式。这些发现增强了对迷走神经损伤神经电反应的理解，并为单侧心脏迷走神经切断术后保留迷走神经传出提供了思路。重要的是，监测心脏右侧 VN 的放电活动可能预测左侧迷走神经通路损伤的发生，这对心脏患者不利，并且可能是房颤导管消融的一种并发症。
