Richmond Laura, Rajappan Kim, Voth Eric, Rangavajhala Vamsee, Earley Mark J, Thomas Glyn, Harris Stuart, Sporton Simon C, Schilling Richard J
Department of Cardiology, St. Bartholomew's Hospital and Queen Mary College, University of London, UK.
J Cardiovasc Electrophysiol. 2008 Aug;19(8):821-7. doi: 10.1111/j.1540-8167.2008.01127.x. Epub 2008 Mar 26.
The complex anatomy of the left atrium (LA) makes location of ablation catheters difficult using fluoroscopy alone, and therefore 3D mapping systems are now routinely used. We describe the integration of a CT image into the EnSite NavX System with Fusion and its validation in patients undergoing atrial fibrillation (AF) or left atrial tachycardia (AT) catheter ablation.
Twenty-three patients (61 +/- 9.2 years, 16 male) with paroxysmal (14) and persistent (8) AF and persistent (1) AT underwent ablation using CT image integration into the EnSite NavX mapping system with the EnSite Fusion Dynamic Registration software module. In all cases, segmentation of the CT data was accomplished using the EnSite Verismo segmentation tool, although repeat segmentation attempts were required in seven cases. The CT was registered with the NavX-created geometry using an average of 24 user-defined fiducial pairs (range 9 to 48). The average distance from NavX-measured lesion positions to the CT surface was 3.2 +/- 0.9 mm (median 2.4 mm). A large, automated, retrospective test using registrations with random subsets of each patient's fiducial pairs showed this average distance decreasing as the number of fiducial pairs increased, although the improvement ceased to be significant beyond 15 pairs. In confirmation, those studies which had used 16 or more pairs had a smaller average lesion-to-surface distance (2.9 +/- 0.7 mm) than those using 15 or fewer (4.3 +/- 0.8 mm, P < 0.02). Finally, for the 13 patients who underwent left atrial circumferential ablation (LACA), there was no significant difference between the circumference computed using NavX-measured positions and CT surface positions for either the left pulmonary veins (178 +/- 64 vs. 177 +/- 60 mm; P = 0.81) or the right pulmonary veins (218 +/- 86 vs. 207 +/- 81 mm; P = 0.08).
CT image integration into the EnSite NavX Fusion system was successful in all patients undergoing catheter ablation. A learning curve exists for the Verismo segmentation tool; but once the 3D model was created, the registration process was easily accomplished, with a registration error that is comparable with registration errors using other mapping systems with CT image integration. All patients went on to have subsequent successful ablation procedures. Where LACA was performed (13 patients), only four patients required segmental ostial lesions to achieve electrical isolation.
左心房（LA）的复杂解剖结构使得仅使用荧光透视法定位消融导管很困难，因此现在三维标测系统已被常规使用。我们描述了将CT图像整合到带有融合功能的EnSite NavX系统中，并在接受心房颤动（AF）或左房性心动过速（AT）导管消融的患者中对其进行验证。
23例患者（年龄61±9.2岁，男性16例），包括阵发性房颤（14例）、持续性房颤（8例）和持续性房速（1例），接受了使用EnSite Fusion动态配准软件模块将CT图像整合到EnSite NavX标测系统中的消融治疗。在所有病例中，CT数据的分割均使用EnSite Verismo分割工具完成，但7例患者需要重复进行分割尝试。使用平均24对用户定义的基准点（范围9至48对）将CT与NavX创建的几何结构进行配准。NavX测量的病变位置到CT表面的平均距离为3.2±0.9mm（中位数2.4mm）。一项大型的、自动化的回顾性测试使用每个患者基准点对的随机子集进行配准，结果显示随着基准点对数目的增加，该平均距离减小，尽管超过15对后这种改善不再显著。经证实，使用16对或更多对基准点的研究中，病变到表面的平均距离（2.9±0.7mm）比使用15对或更少对基准点的研究（4.3±0.8mm，P<0.02）更小。最后，对于13例行左心房环周消融（LACA）的患者，使用NavX测量位置计算的左肺静脉周长（178±64mm vs. 177±60mm；P = 0.81）或右肺静脉周长（218±86mm vs. 207±81mm；P = 0.08）与CT表面位置计算的周长之间无显著差异。
将CT图像整合到EnSite NavX Fusion系统中在所有接受导管消融的患者中均取得成功。Verismo分割工具存在学习曲线；但一旦创建了三维模型，配准过程很容易完成，配准误差与使用其他整合CT图像的标测系统的配准误差相当。所有患者随后均成功进行了消融手术。在进行LACA的13例患者中，只有4例患者需要进行节段性开口病变以实现电隔离。
