500及1000次/分心房电刺激对犬心房肌及肺静脉电生理的影响

The effect of 500 bpm and 1000 bpm stimulation on the electrophysiology of atrium and pulmonary vein in canine

目的观察左心耳500及1 000次/分电刺激对犬心房肌及肺静脉电生理的影响。方法 14条健康成年比格犬随机分为两组,每组7条,2组分别以500及1 000次/分起搏心房16h。测定起搏前及起搏后每2h左、右房和肺静脉左上、左下的房颤诱发率、房颤持续时间、有效不应期(ERP)、并计算有效不应期离散度(dERP)。结果1 000bpm组与500bpm组相比,RA在起搏后2、4、6、8h,LSPV在2、4、6、8、10h,LA、LIPV在起搏后2、4、6、8、10、12h的房颤诱发率增加(P<0.05);RA在起搏后4、6、8、10、12、14、16h,LA、LSPV、LIPV在起搏后2、4、6、8、10、12、14、16h的房颤持续时间均延长(P<0.05);RA在起搏后4、6h,LA在起搏后2、4、6、8h,LIPV在起搏后4、6、8h,LSPV在起搏后2、4、6hERP延长(P<0.05);在起搏后4、6h的dERP变大(P<0.05)。结论 500bpm组在房颤诱发率,房颤持续时间,ERP,dERP均低于1 000bpm组。

Objective To investigate the effects of 500 bpm and 1 000 bpm stimulation on the electrophysiological of atrium and pulmonary vein in canine. Methods Fourteen adult beagle dogs were randomly divided into two groups： 500bpm group （n=7） ,1 000bpm group （n=7） . Multielectrode catheters were sutured to pulmonary veins and atria. At baseline and after pacing every 2 hours, programmed stimulation determined the effective refractory period （ERP）, atrial fibrillation（AF） inducibility and AF duration, and calculated dispersion ERP （dERP）. Results AF induction rates, AF duration, ERP, dERP were lower in 500 bpm group than that in 1 000 bpm group. Effects on AF induction rates： RA in 2,4,6,8h; LSPV in 2,4,6,8,10 h;LA,L1PV in 2,4,6,8,10,12 h increased （P〈0.05）;Effects on AF duration, RA in 4,6,8,10,12,14,16 h;LA,LSPV,LIPV in 2,4,6,8,10,12,14,16 h were prolonged （P〈0.05） ;Effects on ERP： RA in 4,6,LA in 2,4,6,8h,LIPV in 4,6,8 h;LSPV in 2,4,6 h extended （P〈0.05）; Effects on dERP ： dERP in 4, 6 h prolonged （P〈0.05）. Conclusions AF induction rates, AF duration, ERP,dERP in 500bpm group are lower than that in 1 000bpm group.