三维电解剖标测指导疑难右侧游离壁旁路的导管消融

目的应用三维电解剖标测技术详述常规消融无效的右侧游离壁旁路电解剖特征。方法本组共入选17例常规消融无效的右侧游离壁旁路患者，消融失败1～3（1．8±0．6）次。3例在顺向型心动过速下构建右心房电激动模型，14例在右心室心尖部起搏下构建右心房电激动模型。逆向传导的心房最早激动点代表旁路的心房插入端，冷盐水消融最早心房激动点。结果17例患者中，最早激动点距离对应部位三尖瓣环的宽度为9—20（13．6±3．4）mm，较相对部位三尖瓣环的局部激动时间提前18～80（31．5±16．3）ms。共14例患者记录到独立的旁路电位。1例患者在导管标测时阻断旁路逆传，冷盐水局部巩固消融；16例患者冷盐水消融均成功阻断所有旁路的传导，其中1例患者的旁路心房插入端呈广泛分布而行片状消融。无消融术相关并发症。随访了3～41（18．6±12．7）个月，无旁路传导恢复及心动过速发作。结论常规方法消融失败的右侧游离壁旁路可能具有特殊的解剖特征，如旁路在三尖瓣环水平沿心外膜走行，旁路的心房插入部位远离瓣环。三维电解剖标测有助于精确定位旁路的心房插入端并指导消融。

Right-sided free wall accessory pathway refractory to conventional catheter ablation: lessons from three-dimensional mapping

Objective To demonstrate the electroanatomic substrates of right-sided free wall (RFW)accessory pathways (APs) which were refractory to conventional catheter ablation utilizing three-dimensional (3D) mapping. Methods Seventeen patients with RFW APs that failed initial conventional catheter ablation(s)by a mean of 1～3(1.8±0.6) attempts were enrolled in the study. Electroanatomic mapping of the right atrium was performed during right ventricular pacing in 14 patients and orthodromic reciprocating tachycardia in 3patients. Radiofrequency energy was delivered via irrigation catheter to the earliest atrial activation site. Results The earliest atrial activation site, which represented the atrial insertion of the APs, was separated from the tricuspid annulus by an average of 9 ～ 20 ( 13.6 ± 3.4 ) mm, and the local activation time was 18 ～ 80(31.5±16.3) ms earlier than that of the corresponding annular point. The target electrogram demonstrated AP potential in fourteen patients and ventriculoatrial fusion in the rest three. Accessory pathway was blocked in one case during moving the catheter and RF ablation delivery on the areas. One patient exhibited an AP with wide branching on the atrial side during mapping. RF ablation with an irrigated catheter successfully interrupted AP conduction in remaining 16 patients without complications. After a mean follow-up of 3 ～ 41 (18.6±12.7) months, there were no recurrences of ventricular preexcitation or episodes of tachycardia. Conclusion RFW APs refractory to conventional catheter ablation might be due to unique anatomic AP features such as more epicardial course at the annulus level with atrial insertion distance from the tricuspid annulus. Electroanatomic mapping is helpful to accurately localize the atrial insertion sites of these APs and facilitates catheter ablation.