小影像Koch三角及其房室结射频消融应注意的问题

The Cautions of Radiofrequency Current Ablation of Atrioventricular Node for Patients With Small Imaging Koch Triangle

为探讨小影像Koch三角房室结折返性心动过速 (AVNRT)病人射频消融时应注意的问题 ,右前斜位 30°透视下 ,将最大希氏束 (HBE)电位记录处与冠状静脉窦口 (CSo)处的影像距离容纳不下 3个 8F加硬大头电极者定义为小影像Koch三角 ,对 16例小影像Koch三角的AVNRT病人 ,参照慢径消融法行射频消融。结果 :16例病人中 ,成功消融靶点位于CSo水平以下者 12例 ,与CSo位于同一水平者 3例 ,位于CSo水平以上者 1例。 16例病人经消融后房室传导跳跃现象消失者 14例 ;跳跃现象存在 ,但无心房回波 ,异丙肾上腺素亦不能诱发AVNRT者 2例。上述 12例中有 1例于术中出现一过性房室阻滞 (AVB) ,术后 2 4h发生Ⅱ度Ⅱ型AVB ,出院后随访 3个月未能恢复正常 ,因心率为 38～ 5 0次 /分 ,并伴有脑供血不足症状 ,遂置入永久心脏起搏器。其余病人经过 3.5± 1.2 (0 .5～ 5 )年的随访 ,无AVNRT复发 ,亦无AVB发生。结论 :对于小影像Koch三角AVNRT病人的射频消融 ,应突破常规消融时的区位划分概念 ,主要在CSo前下方寻找并消融慢径 ,并根据放电后反应及时调整消融参数。

To investigate radiofrequency current ablation(RFCA) and cautions of atrioventricular nodal reentry tachycardia(AVNRT) in patients with small imaging Koch triangle. The small imaging Koch triangle was defined as that the distance between the site of the largest His potential and coronary sinus ostia(CSo) was not for more than three 8-French big-tip electrodes under X ray fluoroscopy of right anteoblique 30 degree, and the slow pathway were ablated referring to the routine ablating method in 16 AVNRT patients with small imaging Koch triangle. Results: Of 16 patients with small imaging Koch triangle, successful ablating site was located below CSo level in 12 patients, at the same level in 3 and above in 1. The leaping of atrioventricular conduction disappeared in 14 patients, only leaping but no both atrial echo and isoprenaline-induced AVNRT in 2. Among the 12 patients , there was transient atrioventricular block(AVB) during RFCA and type 2 of second degree AVB happened in 1 patient post-procedure 24 hours, which did not improve after 3 months' follow up, thus the patient received cardiac pacemaker. There were no both AVB and AVNRT recurrence in other 15 patients following 3.5±1.2(0.5～5)years. Conclusions: Mapping and ablating of slow pathway could not follow the routine ablating method, mostly, the slow pathway should be mapped and ablated in the ante-inferior field of CS ostia for the patients with small imaging Koch triangle. Meanwhile, it was necessary to regulate ablating parameter instantly according to responses of slow pathway to radiofrequency current.