背景:急性单侧损伤对心脏水平的两个迷走神经自发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)的尖峰活动,研究了右或左心脏迷走神经横断(VNTx)后的即时神经电反应。
方法:14只雄性哥廷根小型猪进行了胸骨切开术。在心电图和血流动力学监测期间,在切口水平以下植入多电极袖带以记录迷走神经电图信号,心脏VNTx之前和之后立即(左:L-cut,n=6;右:R-cut,n=8)。
结果:左心脏VNTx显着降低了迷走神经残端的多单位电活动(MUA)放电率(-30.7%vs预切割)和完整的右VN(-21.8%vs预切割)在心脏水平,在不影响心率的情况下,心率变异性,或者血液动力学.相比之下,右心VNTx在任一VN中均未显著改变MUA,但连续RR间期差异(rMSSD)的均方根略有增加(p<0.022),副交感神经流出指数,而不影响血液动力学。
结论:我们的研究揭示了单侧心脏迷走神经切断术后迷走神经尖峰活动的早期左外侧化模式。这些发现增强了对迷走神经损伤的神经电反应的理解,并为单侧心脏迷走神经切断术后保留迷走神经流出提供了见解。重要的是,监测心脏右VN的尖峰活动可以预测左迷走神经通路损伤的发作,这对心脏病患者有害,并且可能作为心房颤动导管消融的并发症发生。
BACKGROUND: 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).
METHODS: 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).
RESULTS: 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.
CONCLUSIONS: 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.