低强度压力感受器刺激治疗心房颤动的实验研究

Experiment study of treatment on atrial fibrillation with low-level carotid baroreceptor stimulation

目的 探讨低强度颈动脉窦压力感受器电刺激（LL-CBS）对9小时快速心房起搏（9hRAP）所致的心房颤动（AF）的影响。方法 14只比格犬（7-9 kg）麻醉后分为对照组（6只）和LL-CBS组（8只）。将多电极导管缝合于心房和肺静脉。所有动物均接受9hRAP,LL-CBS组的动物在行9hRAP同时给予持续的LL-CBS,将80%阈电压的电刺激定义为LL-CBS。9hRAP后测所有位点的有效不应期（ERP）、ERP离散度及AF诱发窗口（WOV）。实验末留取心房组织采用RT-PCR分析缝隙连接蛋白43（Cx43）的表达情况。结果 与对照组比较,LL-CBS组所有位点的ERP延长,Cx43的DNA含量增加,ERP离散度和AF诱导性降低,差异均有统计学意义（P〈0.05）。结论 LLCBS可抑制AF发生,这种保护机制与调控心房Cx43的表达有关。

Objective To test the hypotheses that low-level carotid baroreceptor stimulation （LL-CBS） protects against atrial fibrillation （AF） induced by 9 hours rapid atrial pacing （9hRAP）. Methods Fourteen anesthetized beagles （7-9 kg） were divided into two groups： control group （6 cases） and LL-CBS group （8 cases）. Multi-electrode catheters were attached to the. atria＇ and pulmonary vein. All animals received 9hRAP, and animals in LL-CBS group received continuous LL-CBS at the same time, a voltage of stimulation setting at 80% below the threshold was defined as LL-CBS. The atrial effective refractory period （ERP）, ERP dispersion and the window of vulnerability （WOV） for AF were measured at all recording sites after 9hRAP. DNA of Atrial tissue was reserved at the end of the protocol and expression of Cx43 was determined by real time polymerase chain reaction （RT-PCR）. Results Compared with control group, in LL-CBS group, ERP in all sites lengthened, DNA of Cx43 increased, ERP dispersion and AF inducibility decreased, the differ ences were statistically significant （P〈 0.05）. Conclusion LL-CBS can suppress AF, the protective effects of LL-CBS may be due to its regulation of atrial Cx43 expression.