心外膜射频消融治疗心房颤动的实验研究

Radiofrequency Ablation of the Epicardium as a Treatment for Atrial Fibrillation in Dogs

为探索心房颤动（ＡＦ）心外膜消融简便方法，选用健康犬及二尖瓣关闭不全模型犬各５只，应用自制线形射频电极沿左、右心耳根部，左房顶部，右心耳根部至下腔静脉根部连线及横跨界沟的线路行心外膜线形消融，同时经冠状静脉窦导管电极消融冠状静脉窦远端。开胸前、关胸后及术后２～５周分别测定ＡＦ诱发率（快速心房起搏、持续静脉滴注乙酰胆碱的条件下）、校正窦房结恢复时间（ＣＳＮＲＴ）、窦率－异丙肾上腺素反应性及高位右房有效不应期（ＨＲＡ－ＥＲＰ）。结果：与术前相比，关胸后及术后２～５周均不能诱发ＡＦ，ＣＳＮＲＴ、ＨＲＡ－ＥＲＰ无变化（Ｐ均＞０．０５），窦率－异丙肾上腺素反应性不降低（Ｐ均＞０．０５）。术后２～５周超声心动图显示心房运动正常、无血栓形成。病理检查证实射频消融区透壁性损伤，而窦房结无损伤。结果表明在心外膜按一定路线射频消融治疗ＡＦ是可行的。

The purpose of this study was to find an easier way to treat atrial fibrillation (AF).Following a designed route,ablation of the epicardium with a lineshaped radiofrequency electrode was performed in 5 normal dogs and 5 mitral valve regurgitation model dogs.Radiofrequency energy was delivered through the epicardial to the lateral right atrium,the top of left atrium,both the right and left atrial appendages,and the crista terminalis.At the same time,catheter radiofrequency ablation was performed in the distal coronary sinus.AF was induced through atrial burst pacing with injecting vein infusion acholine.Inducibility of AF,corrected sinoatrial node recovery time (CSNRT),sinus rateisoproterenol reaction,and high right atrial effective refractory periodes (HRAERP) were examined just before opening chest,after closing chest,and 2～5 weeks postoperation.As a result,AF could hardly be induced after the operation,CSNRT was not prolonged (P>0.05),sinus rateisoproterenol reaction did not decreased (P>0.05),the HRAERP changed little (P>0.05).Echocardiogram examination showed normal atrial movement with no thrombosis after the operation.Pathological examination showed transmural lesions in the radiofrequency ablation zone and did not find any lesion in the sinoatrial node.It demonstrated the procedure of radiofrequency ablating the epicardium could be a practicable treatment for AF.