顽固性房室结折返性心动过速的射频导管消融术

Radiofrequency catheter ablation for the refractory atrioventricular nodal reentrant tachycardia

目的：比较分析68例房室结折返性心动过速（AVNRT）与9例顽固性AVNRT的心电生理特性及临床特点，探讨治疗顽固性AVNRT安全、有效的消融策略。方法：对AVNRT患者，常规取下位法消融，若无效，可逐渐将大头消融电极上移，选择在希氏（His）束与冠状静脉窦口（CSO）中点或稍上方，甚至带小H波放电，消融中在X线下严密观察大头电极是否移动，以防误蚀His束；对房室结双径路（AVNDP）合并房室旁路（AVAP）者。我们均先消融AVAP后再消融AVNDP。结果：普通组68例为单一慢-快型AVNRT，顽固组9例AVNRT中，2例分别合并隐匿性左后间隔AVAP和右侧隐匿性AVAP，1例房室结三径路。结论1对顽固性AVNRT的射频导管消融术（RFCA），应特别强调将X线解剖部位与腔内局部心内膜电图结合起来判断，选择安全有效的靶点图应为小心房（A）波大心室（V）波，A波碎裂，且A波宽度≥68ms，A／V比为0．1—0．25，无H波或H波≤（0．02±0．03）mV。若采用下位法、中位法消融无效，可采用在Koch三角基底部线性消融方法，以避免在上位法消融发生房室传导阻滞并发症。

Objective： To analyze the elcctrophysiological and clinical features of 68 common and 9 refractory atrioventricular nodal reentrant tachycardia （AVNRT） cases, thereby to seek safe and effective strategies for the treatment of refractory AVNRT with radiofrequency catheter ablation （RFCA）. Methods ： Ablation at lower zone is customarily applied in AVNRT, if noneffective, ablation electrode can be gradually moved upward, and radiofrequency energy can be delivered at a midpoint or upper position of His Bundle even with small H waves. The movement of the ablation electrode must be carefully monitored lest His bundle be eroded mistakenly. For those both atrioventricular nodal dual pathways （AVNDP） and atrioventricular accessory pathways （AVAP） are present, we always ablate AVAP first. Results： All 68 common AVNRT cases are simple slow-fast type. Among the 9 cases of refractory AVNRT, 2 cases were combined with concealed left postseptal AVAP and concealed right AVAP respectively, while 1 case with atrioventricular nodal three pathways. Conclusion： X-ray anatomical position and intraventricular local mapping should be analyzed for the use of RFCA in refractory AVNRT. Safe and effective mapping should be ： small A wave and big V wave, shattered A wave with width 〉168 ms, A/V = 0.1 - 0.25, no H or H ≤ （0.02 ± 0.03 ） mV. If lower position and middle position method are noneffective, linear ablation at mid-level of Kochg triangle seems to be a satisfactory alternative, which could avoid complications of atrioventricular block in the upper position ablation.