Lewalter Thorsten, Burkhardt Dietmar, Bielik Helga, Schrickel Jan, Bitzen Alexander, Shlevkov Nikolai, Yang Alexander, Lüderitz Berndt, Schwab Jörg O
Department of Medicine-Cardiology, University of Bonn, Sigmund-Freud-Strasse 25, 53105 Bonn, Germany.
J Interv Card Electrophysiol. 2003 Oct;9(2):269-73. doi: 10.1023/a:1026248827908.
Electrical isolation of pulmonary veins (PV's) is crucial to achieve success in catheter ablation for trigger elimination in focal atrial fibrillation (AF). To guide ostial PV radiofrequency (RF) delivery, it is necessary to identify the electrical breakthrough (EBT) between PV and left atrium. For this purpose, coronary sinus (CS) fixed rate pacing is commonly used. This study evaluated, whether CS extrastimulus pacing is superior in identifying the EBT area as compared to fixed rate pacing.
In 9 patients (51 +/- 10 years) undergoing a left sided electrophysiological study for AF ablation, 25 PV's (10 right and 15 left-sided PV's) were mapped using a 4 French fixed-wire catheter with eight 6 mm coiled Platinum electrodes in a distal looped configuration (Revelation Helix, Cardima Inc.). For mapping and ablation the electrode loop was positioned in the PV ostium rectangular to the longitudinal PV axis. EBT area was identified as those electrodes indicating the earliest PV signals during CS pacing. We measured number of EBT electrodes and time between EBT and the latest activated bipoles at the electrode loop during fixed rate and extrastimulus pacing. The reduction of two or more EBT electrodes was defined as a significant benefit in EBT identification.
In 22 of 25 PV's mapped PV potentials could be observed. Performing fixed rate pacing the EBT area was identified in a mean of 4.2 +/- 1 electrodes, whereas using extrastimulus pacing, EBT area could be significantly reduced to 2.3 +/- 0.8 electrodes. The time between EBT and latest electrode activated increased from 14 +/- 7 ms to 22 +/- 10 ms indicating an intrapulmonary conduction delay during extrastimulus pacing. In 13 of 22 PV's mapped (59%), extrastimulus pacing was beneficial in the identification of the EBT, as the primary target for RF delivery.
CS extrastimulus pacing induces intra-PV decremental conduction properties allowing one to identify a more localised and smaller EBT area as the primary target for RF delivery. Performing PV ablation to treat focal AF, extrastimulus maneuvers allow to unmask the "true" EBT and thus may help to limit intrapulmonary RF delivery.
肺静脉（PV）电隔离对于在局灶性心房颤动（AF）的导管消融中成功消除触发因素至关重要。为了指导肺静脉口部的射频（RF）发放，有必要识别肺静脉与左心房之间的电突破（EBT）。为此，通常采用冠状窦（CS）固定频率起搏。本研究评估了与固定频率起搏相比，CS额外刺激起搏在识别EBT区域方面是否更具优势。
在9例（年龄51±10岁）因AF消融而进行左侧电生理研究的患者中，使用带有八个6毫米盘绕铂电极的4法国固定导线导管，以远端环状配置（Revelation Helix，Cardima公司）对25条肺静脉（10条右侧和15条左侧肺静脉）进行标测。为了进行标测和消融，将电极环置于与肺静脉纵轴成直角的肺静脉口部。EBT区域被确定为在CS起搏期间显示最早肺静脉信号的那些电极。我们测量了固定频率起搏和额外刺激起搏期间EBT电极的数量以及EBT与电极环上最晚激活双极之间的时间。将EBT电极减少两个或更多定义为在EBT识别方面有显著益处。
在25条被标测的肺静脉中的22条中可观察到肺静脉电位。进行固定频率起搏时，平均在4.2±1个电极处识别出EBT区域，而使用额外刺激起搏时，EBT区域可显著减少至2.3±0.8个电极。EBT与最晚激活电极之间的时间从14±7毫秒增加到22±10毫秒，表明在额外刺激起搏期间存在肺内传导延迟。在22条被标测的肺静脉中的13条（59%）中，额外刺激起搏在识别EBT（作为RF发放的主要靶点）方面是有益的。
CS额外刺激起搏可诱导肺静脉内递减传导特性，使人们能够识别出更局限、更小的EBT区域作为RF发放的主要靶点。在进行肺静脉消融治疗局灶性AF时，额外刺激操作可揭示“真正的”EBT，从而可能有助于限制肺内RF发放。
