【摘要】 目的　建立心腔内超声和组织多普勒显像技术引导监控下的希氏束起搏和房室结消融方法。方法　 6只犬急性闭胸模型。经颈静脉插入超声导管确定希氏束和房室结准确空间位置、超声解剖结构标志及其内心肌激动顺序。引导心脏起搏或消融导管到达靶组织 ,监控刺激电极植入过程和确认消融电极与心内膜面接触。分别释放电脉冲进行靶点起搏和射频消融 ,同步体表心电图QRS波形态确认实现希氏束起搏和Ⅲ度房室传导阻滞。结果　实现了直接希氏束起搏 (1例 )和希氏束加室间隔起搏 (5例 )。希氏束起搏阈值为 :电压 (3 .0± 1 .0 )V ,脉宽 0 .5ms。希氏束起搏时导致了较早的室间隔电兴奋。窦性心律和希氏束起搏时QRS波宽度分别为 (59.7± 5 .3)ms和 (82 .8± 1 6 .6)ms (P =0 .0 2 )。完成希氏束起搏和房室结消融的平均操作时间分别为 40min(3～ 81min)和 3min(2～ 5min) ;平均X线曝光时间为 1 3min(1～ 55min)。病理解剖和组织切片表明希氏束起搏和房室结消融定位准确、效果肯定。结论　心腔内超声技术能够准确引导心脏介入导管实现希氏束起搏和房室结消融 ,减少导管操作和X线曝光时间更多还原

【Abstract】 Objective To develop an in vivo procedure f or His bundle pacing (HBP) and radio-frequency (RF) ablation of the atrio-ventricular node (AVN) guided by intracardiac echocardiography (ICE) and tissue Doppler imaging (TDI). The procedure included a custom designed bipolar active fixation pacing lead and steerable delivery catheter, and a commercial RF generator and ablation catheter. Methods Six anesthetized- closed-chest canines were tested. The anatomy in the His bundle and AVN regions, and the onset of myocardial electro-mechanical activation were identified using ICE and TDI. The lead and RF ablation catheter were navigated using an ICE catheter (for local detailed imaging) and fluoroscopy (for global imaging). Surface QRS morphologies were recorded to confirm HBP and third degree block post-ablation. Results Direct His bundle pacing was achieved in one canine, and His + ventricular septal pacing in the remaining five. QRS width in sinus rhythm and HBP were ( 59.7-± 5.3-)ms and ( 82.8-± 16.6-)ms separately (P= 0.02-). The increased QRS width for HBP was due to early septal activation. HBP thresholds were ( 3.0-± 1.0-) volts at 0.5 ms (N=5 due to a late exit block). The mean procedure durations were: HBP 40 minutes (3 to 81 minutes), AVN ablation 3 minutes (2 to 5 minutes), and total X-ray exposure 13 minutes (1 to 55 minutes). Post-mortem analysis of the lead and ablation lesions confirmed correct anatomic localization for HBP and AVN ablation. Conclusions ICE provides precise anatomic guidance of HBP lead implantation and AVN ablation and can significantly reduce exposure to fluoroscopy.更多还原