心房调搏对犬希氏束电位的影响

Effects ofatrial pacing on Hisbundle potential on canines

观察了静注异搏定前(A组)、后(B组)高位右房调搏对10只犬希氏束波(HBP)振幅的影响。A组右房调搏前后的HBP振幅分别为14±4μv和14±4.6μv(P>0.05);B组调搏前HBP振幅为20±7μv。在调搏频率较基础心率快20次/min,电压为起搏阈值的2倍时记录的HBP振幅为34±8.5μv(P<0.05)。调搏刺激电量为受试犬心起搏阈值的3倍,频率高于其基础心率20次/min时,记录的HBP振幅最大。

Effects of high right atrial pacing(HRAP)on His bundle potential (HBP)were studied in canines.Ten mongrel dogs were divided into two groups. HBP was recorded by catheter electrode which wastransvenously located in atrial ventricular junctional region. In non--verapamil injection group,theamplitudes of HBPwere separately 14±4 μV and 14±4. 6μV (P>0. 05)before and after HRAP. Inverapamil injection group, after injecting the drug (0. 25mg/kg), the amplitudes of HBPchanged dra-matically. HBP with 20±7μV was recorded without HRAP. But the amplitude of HBP was 34±8.5μV(P<0. 05 )following HRAP with pacing speed of 20 beats/min faster than the original heart rateand pacing voltage two times of the ventricular threshled. The maximun amplitude of HBP might berecorded with a pacing speed of 20 beats/min faster than the orignal heart rate and pacing voltage threetimes of the ventricular threshold.