Centre de recherche, Hôpital du Sacré-Cœur de Montréal, 5400 Gouin Blvd West,Montréal, Quebec, Canada H4J 1C5.
Cardiovasc Res. 2013 Jul 1;99(1):194-202. doi: 10.1093/cvr/cvt092. Epub 2013 Apr 23.
Given the clinical interest concerning 'reflex vagal' responses to identify left atrial (LA) targets for ablative therapy of atrial fibrillation, we investigated whether vagal and bilateral atrial neural pathways may be involved in chronotropic and atrial repolarization responses to LA ganglionated plexus (GP) stimulation.
Unipolar electrograms were recorded from 191 right atrial (RA) and LA sites in anaesthetized canines prior to and during electrical stimulation of the right vagus nerve (VgN), left VgN, or LAGP at baseline and following (i) bilateral VgN decentralization, and radiofrequency ablation of (ii) periaortic/superior vena cava (Ao/SVC) and (iii) RAGP in 14 animals (anterograde group), and in the reverse order in 7 (retrograde). Repolarization changes were also measured in similar preparations during Ao/SVC (n = 8) and RAGP stimulation (n = 23). Sinus cycle length (SCL) prolongation, and RA and LA repolarization changes (affected atrial surface area) were induced during LAGP stimulation. SCL prolongation and RA repolarization changes were unaffected by VgN decentralization but reduced following Ao/SVC and RAGP ablation in the anterograde group. In the retrograde group, chronotropic and RA repolarization changes were reduced following RAGP and abolished following Ao/SVC ablation. In contrast, LA repolarization responses to LAGP stimulation were reduced following VgN decentralization and each subsequent ablation step, with small residual responses after completing the anterograde protocol. Ao/SVC and RAGP stimulation exerted predominant influences in adjacent regions as well as demonstrating LA extensions.
Vagal as well as bilateral atrial neural pathways are involved in mediating chronotropic and LA repolarization responses to LAGP stimulation.
鉴于人们对“反射性迷走神经”反应的临床兴趣，以确定左心房（LA）作为房颤消融治疗的靶点，我们研究了迷走神经和双侧心房神经通路是否参与了 LA 神经节丛（GP）刺激的变时和心房复极反应。
在麻醉犬中，在电刺激右迷走神经（VgN）、左 VgN 或 LAGP 之前和期间，从 191 个右心房（RA）和 LA 部位记录单极电图，在基线时以及在以下情况下测量复极变化：（i）双侧 VgN 去神经支配，以及（ii）主动脉周围/上腔静脉（Ao/SVC）和（iii）RAGP 的射频消融在 14 只动物（顺行组）中，在 7 只动物中以相反顺序进行（逆行组）。在类似的制剂中，还在 Ao/SVC（n = 8）和 RAGP 刺激（n = 23）期间测量复极变化。LAGP 刺激可引起窦性心动周期长度（SCL）延长以及 RA 和 LA 复极变化（受影响的心房表面积）。SCL 延长和 RA 复极变化不受 VgN 去神经支配的影响，但在前向组中，Ao/SVC 和 RAGP 消融后减少。在逆行组中，RAGP 消融后，RA 变时和复极变化减少，Ao/SVC 消融后消失。相反，LA 复极反应对 LAGP 刺激的反应在前向组完成后减少，并且在完成后仅有很小的残留反应。Ao/SVC 和 RAGP 刺激除了对 LA 有扩展作用外，还对邻近区域有主要影响。
迷走神经和双侧心房神经通路都参与了 LA 神经节丛刺激的变时和 LA 复极反应的调节。
