窦房结脂肪垫对犬右上肺静脉电生理特性影响的研究

目的研究不同水平刺激窦房结脂肪垫(SANFP)对右房(RA)及右上肺静脉(RSPV)的有效不应期(ERP)及心房颤动(简称房颤)诱发率的影响,探讨SANFP对房颤发生维持的作用。方法6只犬麻醉后经右侧开胸暴露RSPV及SANFP,以0.6～2,5,8mV三种不同电压强度水平、60ms频率刺激SANFP,同时以S1S2刺激观察三种水平下RA游离壁远、中、近端及RSPV远、中、近端ERP的变化;同样方法刺激SANFP以S1S1和S1S2程序刺激诱发房颤,测定房颤的诱发率。结果以5mV电压刺激窦房结脂肪垫RSPV近端ERP较基础时明显缩短(90±24msvs109±16ms,P<0.05),其房颤诱发率50%;以5,8mV电压刺激SANFP时RA游离壁近端、中端ERP变化较基础时明显缩短(96±20msvs117±14ms,65±20msvs117±14ms,P均<0.05),其房颤诱发率100%。结论窦房结脂肪垫可能在肺静脉起源的房颤的诱发和维持中起了重要作用。

Electrophysiological changes of the right superior pulmonary vein by sino-atrial node fat pad stimulation in canine

Objective To investigate the electrophysiological characterization of the sino-atrial node fat pad(SANFP)and its potential application to atrial fibrillation(AF).Methods Six healthy anesthesia dogs was chest-opened,then the effective refractory period(ERP)of right superior pulmonary vein(RSPV)was recorded during three(0.6-2,5 and 8 mV)level of electrical stimulation on SANFP.AF inducibility was studied in RSPV and right right atrium(RA)during SANFP stimulating.Results When the fat pad was stimulated,the proximate of RSPV shortened at 5 mV(90±24ms vs 109±16 ms,P<0.05);ERP of right atrium also shortened significantly in 12,34 electrodes at 5,8 mV(96±20 ms vs 117±14 ms,67±35 ms vs 117±14 ms,P<0.05);the rate of induced AF was 50% and 100% in the the proximate of RSPV and 12,34 electrodes of right atrium respectively.Conclusion RSPV is an important substrate in the autonomic nerve mediated AF,and SANFP may play an important role in the initial and maintenance of AF.