非接触标测和频谱分析迷走神经介导的心房颤动

目的： 对在体犬迷走神经介导的心房颤动（房颤）进行非接触标测和频谱分析，以探讨其发生和维持机制。方法: 测定8只犬基础情况及双侧迷走神经刺激时心房有效不应期及其离散度，非接触标测和频谱分析房颤时左、右房的电活动。结果: 迷走神经刺激与基础情况相比，左、右心房有效不应期缩短，但有效不应期离散度增大仅见于左房。迷走神经刺激时房颤易诱发和维持，房颤显示反复有序的激动经优先传导路径传播仅见于左房；频谱分析显示左房的主导频谱高于右房［（12.5±1.5)Hz vs (9.3 ±1.2) Hz，P<0.05］。停止迷走神经刺激，左、右房房颤频谱降低［（9.2±0.5)Hz vs (8.5±0.6)Hz， P>0.05］，房颤自发终止。结论: 左、右房电生理特性改变、激动模式差异以及频谱梯度提示迷走神经介导的房颤发生和维持依赖于左房。

Non-contact mapping and frequency analysis of vagal-mediated atrial fibrillation

AIM: To explore the mechanism of the initiation and maintenance of vagal-mediated atrial fibrillation (AF) by non-contact mapping and frequency analysis of vagal-mediated atrial fibrillation in canine.METHODS: Atrial effective refractory period (AERP) and dispersion of AERP were measured in 8 canine during baseline and bilateral cervical vagal nerve stimulation (CVNS). Left atrium (LA) and right atrium (RA) electrical activity of AF was assessed by non-contact mapping and frequency analysis.RESULTS: Compared with baseline, CVNS attenuated left and right AERP, but only increased the dispersion of left AERP. During CVNS, AF was easily induced and maintained, repetitive organized activations rotated around a preferential route were only found in the LA, and dominant frequencies (DFs) from LA were higher than those of the RA ［(12.5±1.5)Hz vs (9.3±1.2)Hz, P<0.01］. After the cessation of CVNS, DFs of AF decreased in the LA and RA ［(9.2±0.5)Hz vs (8.5±0.6)Hz, P>0.05］, and AF was spontaneously terminated.CONCLUSION: The change of electrophysiological character, difference of activation pattern, and frequency gradient between the LA and RA suggest that the initiation and maintenance of vagal-mediated AF dependent on the LA.