消融次数对心房组织消融透壁性及肺静脉电隔离性的影响

目的 分析不同消融次数对不同厚度的离体猪心房组织消融透壁率及其对肺静脉电隔离的影响.方法 ①40例新鲜猪心用以制备离体心房组织条.将测量后的心房组织按厚度分为＜2 mm（n=152）、2～4 mm（n=192）和＞4 mm（n=136）三组.每厚度组随机选取一半数量的心房组织分为A、B两组,A组采用双极射频消融钳行1次消融,B组行3次消融.消融透壁的指标是消融时该处同时测定的电阻抗＞100 ohm.分别记录A、B组每次消融透壁的时间.②成年猪30头,随机分为C、D两组,每组15头.C组消融左侧肺静脉及左心耳各1次,消融右侧肺静脉及右心耳各3次.D组则消融左侧心房结构3次,右侧心房1次.消融前后同步记录左心房及肺静脉电位,并起搏肺静脉视左心房是否被起搏.离体及活体消融线标本均固定后切片,使用Masson染色,镜下观察消融处组织学变化及透壁性情况.结果 离体实验A、B两组透壁率分别为51.3％和98.3％.A组不同心房厚度组间单次消融时间有显著差异.B组同一部位多次消融,消融时间递减.活体实验单次及3次消融后肺静脉电隔离率分别为72.2％和100％.结论 使用国产双极消融装置3次消融显著提高心房组织透壁率及肺静脉电隔离率。

Pathological transmural and conduction block of atrial tissue after once and triple times of bipolar radiofrequency ablation

Objective To analyze the transmural and electrical isolationofpulmonary veins by once or triple times of radiofrequency（RF） ablationdelivered by domestic made RF ablation system. Methods Atrial tissue stripes were prepared from 40 fresh porcine heart. They were allocated to 〈2, 2-4, and 〉4 mm groups according to tissue thickness. Half of tissue from the same thickness group was randomly selected and ablated once by RF （Group A ） while the other half was ablated triple times （Group B ）. Ablation time was recorded for each time of ablation. Thirty pigs were anaesthetized and had median sternotomy. Fifteen pigs had their left pulmonary veins and left atrial appendages ablated once while their right pulmonary veins and atrial appendage ablated triple times （Group C ）. The other 15 pigs had right side lesions triply ablated while their left lesions ablated once （Group D ）. Epicard~alelectrocardiogram were recorded on left atrium and pulmonary vein simultaneously before and after abla- tion. Isolated pulmonary veins were paced to see if the conduction block was complete. All tissue around the ablation line was send for Masson trichrome stain. Pathological transmural were check by microscope. Results Pathological transmural was achieved in 51.3% and 98.3% atrial tissue in Group A and B respectively. In group A, ablation time was significantly different between groups of different tissue thickness. Time for 2nd and 3rd ablation became significantly shorter as compared with first-time ablation. Electrical isolation of pulmonary veins were recorded in 72.2% by once ablation and 100% by triple ablations. Conclusion RF ablation for three times could significantly improve transmural and electrical isolation of pulmonary veins as compared with ablation for once.