去自主神经条件下迷走神经刺激对肺静脉不同部位有效不应期的影响

目的探讨去自主神经条件下迷走神经刺激对肺静脉不同部位有效不应期(ERP)的影响。方法10只成年健康杂种犬,常规戊巴比妥钠麻醉,气管插管,接呼吸机,暴露并切断双侧颈迷走神经干,破坏颈交感神经节。双侧开胸,刺激电极分别与左、右心耳、左房及四支肺静脉缝合,行程序刺激,观察在基础状态、双侧强迷走刺激及阿托品作用时肺静脉不同部位ERP的变化。结果迷走神经刺激明显缩短肺静脉不同部位的ERP,而阿托品则可拮抗这种缩短。结论迷走神经刺激缩短肺静脉的ERP并参与房颤的发生。

Effects of vagal stimulation on effective refractory period of pulmonary veins after autonomic denervation

Objective To investigate effects of vagal stimulation on effective refractory period (ERP) at different sites of pulmonary veins after autonomic denervation. Methods 10 mongrel dogs were anesthetized with pentobarbital. The cervical vagal trunks were isolated bilaterally and decentralized. The ansae subclaviae were exposed bilaterally as they exited from the stellate ganglia, doubly ligated, and cut. After bilateral thoracotomy, multielectrode catheters were sutured to the left atrial appendage(LAA), the right atrial appendage(RAA), the left atrium(LA), and 4 pulmonary veins. ERP were determined at different sites of atria and 4 pulmonary veins in the baseline state, during bilateral vagal nerve stimulation (VNS) and intravenous infusion of atropine. Results VNS shortened the ERP at all sites. Intravenous infusion of atropine abolished the ERP shortening. Conclusion The vagal stimulation shortens ERP of pulmonary veins which involves in the initiation of focal atrial fibrillation.