Lim Kang-Teng, Murray Connor, Liu Hao, Weerasooriya Rukshen
Department of Cardiology, Royal Perth Hospital, GPO Box X2213, Perth, Western, Australia.
Europace. 2007 Mar;9(3):149-53. doi: 10.1093/europace/eul187. Epub 2007 Jan 25.
In this prospective pilot study, pre-procedural MRI was performed on patients undergoing radiofrequency ablation of the cavotricuspid isthmus (CTI) to assess variation in isthmus anatomy and its impact on catheter ablation.
In 41 patients, 34 males, mean age 56 +/- 11.5 years, pre-procedural MRI was performed prior to ablation. On the basis of the magnetic resonance imaging (MRI), isthmus length and description of isthmus morphology was determined. Catheter ablation of the CTI was then performed using a standard technique by an experienced operator without prior knowledge of the MRI findings.
The following morphological variants of isthmus morphology were demonstrated: long isthmus, concave isthmus shape, simple pouches, and eccentric septally directed pouches distinct from the coronary sinus. There was a trend towards longer RF times for long and concave shaped CTI. Eccentric septally directed pouches were associated with significantly longer radiofrequency energy delivery times (29.5 +/- 24.5 min RF versus 14.5 +/- 12.9 min RF; P = 0.037).
The anatomy of the CTI is highly variable. Ablation difficulty can be predicted by the presence or absence of morphological variants and the length of CTI demonstrated by cardiac MRI.
在这项前瞻性试点研究中，对接受三尖瓣峡部（CTI）射频消融术的患者进行术前磁共振成像（MRI），以评估峡部解剖结构的变异及其对导管消融的影响。
对41例患者（34例男性，平均年龄56±11.5岁）在消融术前进行了术前MRI检查。根据磁共振成像（MRI）确定峡部长度和峡部形态描述。然后由经验丰富的操作人员使用标准技术对CTI进行导管消融，操作人员事先并不知晓MRI检查结果。
显示出以下峡部形态学变异：峡部长、峡部呈凹形、单纯袋状以及与冠状窦不同的偏心性间隔方向袋状。峡部长和呈凹形的CTI有射频时间延长的趋势。偏心性间隔方向袋状与显著更长的射频能量释放时间相关（射频时间29.5±24.5分钟对14.5±12.9分钟；P = 0.037）。
CTI的解剖结构高度可变。心脏MRI显示的形态学变异的有无以及CTI的长度可预测消融难度。
