Thornton A S, Janse P, Theuns D A M J, Scholten M F, Jordaens L J
Clinical Electrophysiology Unit, Department of Cardiology, Thoraxcentre, Erasmus MC, Dr Molewaterplein 40, 3015 GD Rotterdam, The Netherlands.
Europace. 2006 Apr;8(4):225-30. doi: 10.1093/europace/euj026. Epub 2006 Feb 21.
Steering soft, flexible catheters using an external magnetic field could have advantages for heart catheterization, especially for therapy of tachyarrhythmias. Our aims were to assess the feasibility of magnetic navigation to Koch's triangle and reliable ablation of atrioventricular nodal re-entry tachycardia (AVNRT) with a magnetic catheter.
Consecutive patients with AVNRT were mapped and ablated with a magnetically enabled catheter (Helios I or II), with, respectively, one and three magnets at the tip. The catheter was remotely advanced with the Cardiodrive system and orientated with the Navigant control system. After initial positioning with the external magnets, adjustment was made in 5 degrees steps. Success rates, procedure, and fluoroscopy times were analysed, and compared with a local contemporary series of conventional AVNRT ablations. Magnetic navigation was feasible in all 20 patients. Targets were easily reached. Catheters remained stable in position during accelerated junctional rhythms. Ablation was successful in 18/20 procedures (90%). No significant complications occurred. Median patient fluoroscopy time was 12 min, median physician fluoroscopy time was 4 min. Fluoroscopy times tended to be shorter than that in the conventionally treated group. Procedure duration decreased significantly over time, median procedure time was similar to that in the conventional group.
AVNRT can be successfully mapped and ablated using magnetic navigation. A learning curve was evident, unrelated to catheter type, but to increasing operator experience. Physician radiation times were one-third of patient times. No complications occurred. Procedure time is comparable with that of conventional ablation.
利用外部磁场操控柔软、灵活的导管进行心脏导管插入术可能具有优势，尤其是在治疗快速性心律失常方面。我们的目的是评估磁导航至科赫三角的可行性以及使用磁性导管可靠消融房室结折返性心动过速（AVNRT）的效果。
连续纳入患有AVNRT的患者，使用配备磁体的导管（Helios I或II，尖端分别有1个和3个磁体）进行标测和消融。通过Cardiodrive系统远程推进导管，并通过Navigant控制系统进行定向。在使用外部磁体进行初始定位后，以5度步长进行调整。分析成功率、手术过程和透视时间，并与当地同期进行的一系列传统AVNRT消融术进行比较。磁导航在所有20例患者中均可行。目标易于到达。在加速性交界性心律期间，导管位置保持稳定。18/20例手术（90%）消融成功。未发生明显并发症。患者透视时间中位数为12分钟，术者透视时间中位数为4分钟。透视时间往往短于传统治疗组。手术持续时间随时间显著缩短，手术时间中位数与传统组相似。
使用磁导航可以成功地对AVNRT进行标测和消融。存在明显的学习曲线，与导管类型无关，而与术者经验的增加有关。术者的辐射时间是患者辐射时间的三分之一。未发生并发症。手术时间与传统消融术相当。
