Research Center and Department of Medicine, Montréal Heart Institute and Université de Montréal, 5000 Belanger Street, Montreal, QC, Canada H1T 1C8.
Cardiovasc Res. 2011 Mar 1;89(4):825-33. doi: 10.1093/cvr/cvq332. Epub 2010 Oct 20.
Pulmonary vein (PV)-encircling ablation, which is effective in suppressing atrial fibrillation (AF), damages autonomic ganglia near the PV ostia. This study examined the effects of PV isolation (PVI) vs. peri-PV ganglionic plexus ablation (GPA) in two discrete canine AF models: ventricular tachypacing (240 bpm, 2 weeks)-induced congestive heart failure (CHF), and atrial tachypacing (400 bpm, 1 week)-induced atrial tachycardia remodeling (ATR).
All PVs were isolated with an epicardial radiofrequency clamp in nine CHF and eight ATR dogs. Peri-PV ganglionic plexi (identified by bradycardic responses to high-frequency stimulation) were ablated in six CHF and five ATR dogs with an epicardial radiofrequency-ablation pen. Electrophysiologic measurements, including 240-electrode AF mapping, were obtained and dominant frequencies (DFs) determined. Atrial growth associated protein-43 (GAP-43) and neurofilament-M (NF-M) expression were determined immunohistologically. In CHF, neither PVI nor GPA affected AF duration, DF or the already low AF vulnerability. In ATR, PVI reduced AF vulnerability (75 ± 6% to 55 ± 11%, P< 0.05) but did not alter AF duration or DF. In contrast, GPA prolonged atrial refractory period and decreased AF vulnerability (75 ± 8 to 30 ± 10%, P< 0.05), AF duration (617 ± 246 to 39 ± 23 s, P< 0.01), and DF (11.4 ± 0.6 to 8.6 ± 0.3 Hz, left atrium) in ATR dogs. Both GAP-43 and NF-M expression were decreased in CHF (by 63.1** and 60.0%) and increased in ATR (by 65.5 and 92.1%, P< 0.001) compared with control.
PVs play a minor role in experimental AF due to CHF or ATR, but autonomic ganglia are important in AF related to ATR. Differential neural remodelling may contribute to varying effects of GPA in discrete AF substrates.
肺静脉（PV）环周消融可有效抑制房颤（AF），但会损伤 PV 口附近的自主神经节。本研究在两种不同的犬 AF 模型中比较了 PV 隔离（PVI）与 PV 周围神经丛消融（GPA）的效果：心室快速起搏（240 次/分，2 周）诱导充血性心力衰竭（CHF），以及心房快速起搏（400 次/分，1 周）诱导的房性心动过速重构（ATR）。
在 9 只 CHF 犬和 8 只 ATR 犬中，使用心外膜射频钳对所有 PV 进行隔离。在 6 只 CHF 犬和 5 只 ATR 犬中，使用心外膜射频消融笔消融 PV 周围神经丛（通过高频刺激引起的心动过缓反应来识别）。进行电生理测量，包括 240 电极 AF 标测，并确定主导频率（DF）。免疫组化检测心房生长相关蛋白-43（GAP-43）和神经丝-M（NF-M）的表达。在 CHF 中，PVI 或 GPA 均不影响 AF 持续时间、DF 或已经很低的 AF 易感性。在 ATR 中，PVI 降低了 AF 易感性（75±6%降至 55±11%，P<0.05），但不改变 AF 持续时间或 DF。相比之下，GPA 延长了心房不应期并降低了 AF 易感性（75±8%降至 30±10%，P<0.05）、AF 持续时间（617±246 降至 39±23 s，P<0.01）和 DF（11.4±0.6 降至 8.6±0.3Hz，左心房）在 ATR 犬中。与对照组相比，CHF 中 GAP-43 和 NF-M 表达均降低（分别降低 63.1和 60.0%），而 ATR 中均升高（分别升高 65.5**和 92.1%，P<0.001）。
在 CHF 或 ATR 引起的实验性 AF 中，PV 作用较小，但自主神经节在与 ATR 相关的 AF 中很重要。不同的神经重塑可能导致 GPA 在不同的 AF 底物中产生不同的效果。
