摘要
目的研究犬Bachmann束在迷走神经介导的心房颤动(迷走性房颤)维持中的作用。方法刺激犬颈部双侧迷走神经干并诱发出持续性房颤,对8只犬的Bachmann束经心外膜途径进行标测和消融,在主动脉根部后方,左、右心耳连线中点处射频消融完全阻断Bachmann束传导,消融Bachmann束前后分别测左、右心房有效不应期,Bachmann束传导,左、右房间传导时间,并用相同刺激方案诱发迷走性房颤,测量房颤波周长(AFCL),房颤诱发及持续时间,观察消融Bachmann束对迷走性房颤诱发及维持的影响。结果8只犬完成实验,均达到完全消融阻断Bachmann束传导,消融前后左、右心房之间传导显著延迟(P<0.01),左、右心房不应期无明显变化,消融后左、右心房及Bachmann束的AFCL较消融前延长(P<0.05),其中5只犬消融后高频刺激不能诱发出持续性房颤。结论本研究提示Bachmann束在犬迷走性房颤的维持中起一定的作用。
AIM To investigate the role of Bachmann's bundle (BB) in the maintenance of sustained vagotonic atrial fibrillation in canines. METHODS Cervical vagal stimulation was performed in 8 canines. All the canines were instrumented with epicardial electrodes patches on free walls of both right and left atrial appendage. Sustained AF was induced by burst atrial stimulation and BB ablation was achieved using radiofrequency catheter ablation epicardially. Atrial effective refractory period (AERP), atrial fibrillation cycle length ( AFCL), AERP difference between left and right atrium, conduction characters of BB, conduction time between left and right atrium, inducibility and duration of AF were measured before and after BB ablation during vagal stimulation. RESULTS Eight canines were studied. After ablation of BB, conduction between LA and RA prolonged significantly(P 〈 0.01 ). AERP changed from ( 109±3 ) ms to ( 112 ± 7 ) ms at the left atrium and from ( 116 ± 9 ) ms to ( 112 ±14 ) ms at the right atrium. Before ablation ofBB, AFCL of left and right atrium and BB were (88±8)ms, (84 ±13)ms and (91± 19 ) ms, respectively. After ablation of BB, AFCL of left and right atrium and BB were ( 107 ± 17 ) ms (P〈 0.05, vs preablation), ( 105 ± 13 ) ms ( P 〈 0.05, vs preablation) and ( 119 ± 10) ms ( P 〈 0.05, vs pre-ablation) respectively. Complex fractionated atrial electrograns reduced significantly in BB after ablation of BB. Before ablation, sustained atrial fibrillation was induced in eight canines. After ablation, sus-tained atrial fibrillation was induced in three canines. In the other five canines, AF terminated spontaneously in 30 seconds. CONCLUSION Bachmann's bundle may play a role in the perpetuation of vago-tonic AF in canines.
出处
《心脏杂志》
CAS
2007年第3期286-288,292,共4页
Chinese Heart Journal